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Densities and melting points of normal straight chain hydrocarbons Keays, John Lake 1942

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DENSITIES AND MELTING POINTS OF i .NORMAL STRAIGHT-CHAIN HYDROCARBONS  by JOHN LAKE KEAY'S  Thesis submitted.in P a r t i a l of t h e Requirements :  ...  '  Fulfillment  f o r t h e Degree  of.  MASTER- OF.APPLIED SCIENCE ' ' ~" , •  i n t h e Department of ' CHEMICAL ENGINEERING:-  The U n i v e r s i t y  of B r i t i s h  May,  1942.  Columbia  PREFACE The w o r k d e s c r i b e d i n t h i s t h e s i s r e p r e s e n t s ; ( l ) t h e a u t h o r ' s own r e s e a r c h e s d u r i n g t h e p a s t y e a r , and (2) c o r r e l a t i o n o f t h i s work w i t h t h a t o f o t h e r w o r k e r s  a i n the  same f i e l d , , , p a r t i c u l a r l y o f t h o s e who p r e c e d e d t h e a u t h o r i n this  laboratory. The u l t i m a t e p u r p o s e  d a t a on t h e n o r m a l  o f t h i s p r o j e c t was t o c o l l e c t ; ,  s t r a i g h t - c h a i n hydrocarbons,  such d a t a t o  be o f v a l u e t o t h e p e t r o l e u m i n d u s t r y a n d t h o s e w o r k i n g w i t h petroleum products.  T h a t ..the p e t r o l e u m i n d u s t r y i s i n t e r e s t e d  i n s u c h i n f o r m a t i o n i s p r o v e d by t h e f a c t . t h a t i t s p o n s o r s v a s t amount  o f p h y s i c a l and c h e m i c a l r e s e a r c h .  a  In particular,  t h e p r e s e n t w o r k was made p o s s i b l e by a s c h o l a r s h i p from: the: S t a n d a r d O i l Company o f ' B r i t i s h C o l u m b i a , a n d t h e a u t h o r wishes t o express h i s thanks f o r t h i s  assistance.  I n a d d i t i o n , t h e a u t h o r w o u l d / l i k e t o t h a n k D r . W.F... Beyer, o f the Department o f C h e m i s t r y , f o r h i s c o n s t a n t h e l p and a d v i c e t h r o u g h o u t t h e c o u r s e o f t h e w o r k .  1  - • -  S e v e r a l o f . t h e s e n i o r . s t u d e n t s , a l s o , gave v a l u a b l e a s s i s t a n c e i n .the p r e p a r a t i o n a n d p u r i f i c a t i o n o f t h e h y d r o c a r b o n s ; two o f t h e most h e l p f u l were E .L.. . S m i t h , a n d S. Cavers.  Signed? May,  1942.  CONTENTS .1  Introduction. M a t e r i a l s Used ' S y n t h e s i s . . . . . v.. . Purification.......;.  ...................... .2 <,.«,2 ;/  Experimental Procedure T e m p e r a t u r e C o n t r o l . . . . . . . . . . . . . . . . . . . . . . . . . . 10 D i l a t o m e t e r Tube * . . l l C a l i b r a t i o n o f D i l a t o m e t e r Tube. ....12 .15:  M e l t i n g P o i n t s of the Hydrocarbons (Table  o f S e l e c t e d V a l u e s ) . . . . . . . . . . . . . ... . .58  G~©n© 1^3,1 Tfi© Gjtr*y«»* • • • • * • • • • •» • • • * • • * • • *  ••«•»«•  3.3  R e s u l t s a n d General D i s c u s s i o n o f Each Hexadecahe .... .....46 p « 0 «•••-•<• c 5^ D oiccoos s an . S £iexi.©.•••••« *•# ••• e <• s •• « • • © • 55,-Tetracosane • • • « ••**«*« »« e *59 Hexacosane. fii. Octacosane. Nonacosane. .... ...66 T r i a c o n t a n e . ............... ..... . .68 D o t r i a c o n t a n e . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 • i »•»  i » •  •  c  •  •  • » » » • • • « » »  t  »  • i.  Correlation of Results sjL*tjxon . P o i x i t 3 • » • 75.... L i m i t of T r a n s i t i o n Points... ...77 Shape o f . C u r v e s o v e r E n t i r e Range.'.............81 •  1  3 utiniiiSjX y •• • • • « • • Bit)  •  •  •  «  «  «  »  •  e**• •  « » »  •  • ••  «« * • «***.».» • •. • ^ » » •«• • *»«««.•»•.«.*.• ••»••• 35  o^3^*3i^)i!i » • * • • • • • • « • • * * • * •  • •<»«•.• ».•»•.*••.• • •.«8 6  Appendix... I ( P r e p a r a t i on a n d P u r i f i c a t i o n )  8'9  A p p e n d i x I I (Sample C a l c u l a t i o n s ) ....................*95 A p p e n d i x I I I ( S p e c i f i c Volume o f M e r c u r y ) . . . . . . . 9 8 " Appendix;.IV/ ( D e n s i t y V a l u e s ) ........  .........100  DENSITIES AND MELTING POINTS OF NORMAL STRAIGHT-CHAIN HYDROCARBONS This i n v e s t i g a t i o n and others c a r r i e d out i n the same laboratory are intended' t o serve two ends.  From a  purely t h e o r e t i c a l p o i n t of view, they add t o the general accumulation  of s c i e n t i f i c data.  primary need i n design work.  In a d d i t i o n , they are a  The design of p l a n t s  or  the?  development of chemical processes on a commercial scale w i l l be, i n general, e f f i c i e n t and p r o f i t a b l e i n d i r e c t proportion! to the number of unknown f a c t o r s which can be e l i m i n a t e d . These unknowns u s u a l l y i n v o l v e p h y s i c a l constants of the reacting  substances. The p r e c i p i t a t i o n o f the heavy hydrocarbons i n  petroleum by the a d d i t i o n of l i g h t p a r a f f i n s may be taken as a p r a c t i c a l example of the need f o r exact p h y s i c a l d a t a . In order t o increase the e f f i c i e n c y of the process, i t was f i r s t necessary t o o b t a i n accurate and complete data on the mutual s o l u b i l i t y of the p a r a f f i n s .  A study of these  solu-  b i l i t i e s l e d : t o an i n v e s t i g a t i o n i n t o the phase r e l a t i o n ships between d i f f e r e n t members of the p a r a f f i n  series..  A part o f t h i s work d e a l t with the s o l u b i l i t y of 32 i n v a r i o u s lower members o f the normal, s t r a i g h t - c h a i n 2  aliphatic series. ^  I t was d i s c o v e r e d t h a t the f r e e z i n g -  —2--  point curves of d i c e t y l i n propane and  "butane showed a  change i n curvature at approximately 15°C p o i n t of the the  fact.that  forms, and  2  dicetyl. ^  below the  T h i s d e v i a t i o n was  attributed  d i c e t y l e x i s t e d i n at l e a s t two  i t was  meltingto  crystalline  found necessary to obtain more p r e c i s e  i n f o r m a t i o n on the  c r y s t a l l i n e s t r u c t u r e of the  paraffin  hydrocarbons.  •  Since v a r i a t i o n to be was  i n c r y s t a l l i n e s t r u c t u r e was  accompanied i n many cases by  decided to study the  variation  i n density,, i t :  change of density of the  p a r a f f i n members with change i n temperature.  known  The  pure dilato-  metric method, seemed to be  best s u i t e d  f o r t h i s purpose.  The  investigation  d e n s i t y and  t r a n s i t i o n p o i n t s off  the  higher a l i p h a t i c hydrocarbons was  i n t o the  continued by Yatabe32 and  begun by M o r r i s - ^  and  21  Patterson -'.  MATERIALS USED Synthesisi I t was members of the  necessary f i r s t series  of a l l to  obtain•individual  i n as pure a state as p o s s i b l e .  homologues s t u d i e d thus f a r have been 16-34- i n c l u s i v e the  even members, and  the  single  odd  member 2 9 .  of each specimen used, together with d e t a i l s of are given i n Appendix. I . Purification; In the case of p r a c t i c a l l y a l l the synthesized i n t h i s l a b o r a t o r y , the  first  The  The for sources  purification,  hydrocarbons  step i n p u r i f i -  c a t i o n was  to heat the crude product with small p o r t i o n s of  concentrated s u l p h u r i c a c i d at 130°C,  f o l l o w i n g the method:  2 2  of P i p e r . ' The.sulphuric a c i d q u a n t i t a t i v e l y removed ketones and a l c o h o l s .  In general t h i s treatment  r a i s e somewhat the m e l t i n g p o i n t of the sample.  tends t o Because the  f a t t y a c i d s are s o l u b l e to an a p p r e c i a b l e extent i n sulphuric; a c i d , whereas t h e o r e t i c a l l y the hydrocarbons are not, treatment  should a l s o be e f f e c t i v e i n removing any  this  fatty  a c i d impurity remaining from the Peterson s y n t h e s i s . ( c f . p.. ) The m e l t i n g ' p o i n t s of the p a r a f f i n s b e i n g somefehat higher: than those of the corresponding f a t t y a c i d s from which they are made, i t i s reasonable to suppose that removal of any a c i d impurity present .would r a i s e the m e l t i n g p o i n t of the. hydrocarbon.  In p r a c t i c e i t i s found t h a t there i s considerable: l o s s of hydrocarbon  i n the hot, concentrated s u l p h u r i c ac&dU  P i p e r mentions a l o s s up to 2<2?o  9  l e a s t , the loss,was  c l o s e r to 5 0 ^ before completely  free, s u l p h u r i c . a c i d was hydrocarbon.  but i n the case of 2 0 a t chair-  obtained upon h e a t i n g with the  In the case of 18 the hydrocarbon  was  consi-  dered too v a l u a b l e to r i s k l o s i n g a l l or any p a r t of i t i n t h i s was;  i n consequence i t was  not t r e a t e d with sulphuric,  acid.  For those p a r a f f i n s s y n t h e s i z e d by a Grignard 1  reagent, Oldham and Ubbelohde ^ suggest t h a t a more r a p i d  p u r i f i c a t i o n can "be e f f e c t e d by h e a t i n g the p a r a f f i n with 2 0 ^ oleum at 100°C. u n t i l the t e s t f o r h a l i d e i s negative, then h e a t i n g f o r a short time with concentrated sulphuric, a c i d a t 130°G; i n order t o remove any sulphonic a c i d s p r e s e n t . F o l l o w i n g i s a d e s c r i p t i o n of the general method and apparatus used i n the p u r i f i c a t i o n of many of the homologues . i n v e s t i g a t e d .  The method d e s c r i b e d was employed f o r  18, 2 0 , 2 6 , and 3 4 .  The most common method of p u r i f i c a t i o n  involves  the r e c r y s t a l l i z a t i o n of the hydrocarbon from some solvent such as a c e t i c a c i d , e t h y l a l c o h o l , or e t h e r .  Acetic  acid  i s c o n s i d e r e d to be the best s o l v e n t , because the h i g h e r members o f the p a r a f f i n s e r i e s are only s l i g h t l y  soluble  i n g l a c i a l a c e t i c a c i d a t b o i l i n g temperatures, and- almost • completely i n s o l u b l e i n the a c i d at room temperatures.  The  l a r g e r the volume of s o l v e n t used f o r a given weight of hydrocarbon, the greater w i l l be the amount o f s o l u b l e impurity removed.  I n p r a c t i c e the p a r a f f i n i s d i s s o l v e d  i n h o t , g l a c i a l a c e t i c a c i d by r e f l u x i n g to the extent of from 1-3 grams of hydrocarbon per l i t e r of a c i d .  Upon  c o o l i n g , the hydrocarbon c r y s t a l l i z e s out i n a mass o f s m a l l , white n e e d l e s .  T h i s procedure i s repeated u n t i l the  sample gives a constant m e l t i n g p o i n t .  In some cases i t was found necessary t o repeat the c r y s t a l l i z a t i o n s as many as twenty times, ,the f i n a l ' m e l t i n g  p o i n t being approached a s s y m p t o M c a l l y .  In order t o f a c i l i -  -  t a t e the o p e r a t i o n a n d to reduce the p o s s i b i l i t y of contamina t i o n from outside sources, the apparatus shown i n Figure I was  devised and blown from pyrex g l a s s . Two  condenser.  6 - l i t e r f l a s k s are connected as shown across a  The hydrocarbon to be p u r i f i e d isr. d i s s o l v e d i n  pure g l a c i a l a c e t i c a c i d and poured i n t o f l a s k B-3 through the* condenser under vacuum a p p l i e d through 1 and 3 .  If this  method i s not p r a c t i c a l , then B 3 i s f i l l e d with thd a c i d andt the  soled hydrocarbon i s dropped down through the condensers  F l a s k B5is then heated and the mixture i s allowed t o r e f l u x for  s e v e r a l hours.  By t h i s method i t was  p o s s i b l e to p u r i f y  up to 5 0 grams of the hydrocarbon at one time.  The a c i d was  allowed to c o o l to room temperature,  whereupon the hydrocarbon c r y s t a l l i z e d out and c o l l e c t e d as a d i f f u s e white, c l o u d - l i k e l a y e r on top of the a c i d . The s e c t i o n marked ( 6 ) i n f i g u r e I c o n s i s t s of four inches o f . 1 - i n c h bore pyrex: g l a s s , j o i n e d on to i - i n c h bore tubing. f l a s k A.  T h i s t u b i n g i s connected through stop-cock 4. t o The expanded s e c t i o n 6 . i s f i l l e d w i t h acid-washed",  g l a s s wool and so packed as t o provide a f i l t e r  f o r the hydro-  carbon c r y s t a l s and whatever s o l i d or i n s o l u b l e impurity be with the sample b e i n g p u r i f i e d .  might  With stopcocks 3 and 2  c l o s e d , s u c t i o n i s a p p l i e d through 1 ,  t r a n s m i t t e d through  stopcock 4 , through 5 and 6 t o the bottom of f l a s k B.  When  a l l the mother l i q u o r has cocks 2 and to f l a s k A.  4 are  "been drawn i n t o A from; B,  stop-  3 i s opened, and heat i s  applied  closed,  A c i d i s d i s t i l l e d i n t o B u n t i l one  remain i n the bottom of  inches  A.  With successive c y c l e s i n B. becomes cleaner and regular  or two  of o p e r a t i o n the  hydrocarbon  the a c i d i n A becomes d i r t i e r .  At,  i n t e r v a l s a sample of hydrocarbon i s withdrawn from  B.  This i s done as follows?  has  been suctioned i n t o A, a long glass tube i s i n s e r t e d  to B through the mouth of the several are  cc.of a c i d and  when a l l but  50-100cc. of a c i d  condenser at 7, through which  c r y s t a l s are drawn o f f .  The  crystals  f i l t e r e d o f f , washed thoroughly with d i s t i l l e d water,  d r i e d , and  a m e l t i n g point  determination i s made.  When the hydrocarbon i s considered pure, as i n d i c a t e d by and  in  4- are  closed,  constant melting p o i n t ,  pressure i s a p p l i e d  d i r t y a c i d i s discharged through 2.  sufficiently stopcocks 3  through 2, and The  by t h i s time contains m e g l i g i b l e soluble  c o l d a c i d , which impurity, i s drawn  from B:3 i n t o A, heated i n order to ensure complete of ,A, and  as before, H>lown out .through 1.  the  cleansing  M a s k B3 i s then  r e f i l l e d with f r e s h acetic, a c i d , heated to boiling,., and e n t i r e contents of the  f l a s k , that i s , a c i d and  l i q u i d , hydrocarbon was  not  the:  whatever  taken i n t o s o l u t i o n d u r i n g  r e f l u x i n g , are drawn over i n t o A.  From there they are  or blown d i r e c t l y i n t o a r e c e i v i n g  flask.  the drawn  A l l passages are:  — 8 —  c l e a r e d of hydrocarbon by drawing hot a c i d washings down through 7 , ; up. through 6, 5 , and 4 , and out at 1 . The method was found t o be slow i n the case of 34,_as the higher members of the s e r i e s are i n c r e a s i n g l y insoluble i n acetic acid.  Carothers^- made use of the  f o l l o w i n g solvents f o r the p u r i f i c a t i o n of h i g h e r a l i p h a t i c : members; Member.. 20  M e l t i n g Point. ' 3 5 . 0 - 35*6' 66.0  Solvent used f o r C r y s t a l l i z a t i o n Absolute E t h y l a l c o h o l  30  65.0-  40  80.5r 81.0  Ethylene C h l o r i d e  91.9-  92.3::  L i g r o i n p l u s Petroleum Ether  98.5-  99.3. '  B u t y l Acetate  50  ;  60 70  105*  -105.5  Absolute E t h y l plus E t h y l Ether  B u t y l Acetate Table I.,  A slight m o d i f i c a t i o n i n the above method of: p u r i f i c a t i o n was necessary f o r the lower members such as 2 0 . In t h i s case the hydrocarbon was too s o l u b l e i n the a c i d aU room temperatures t o e f f e c t ; a good s e p a r a t i o n of c r y s t a l s , , so f l a s k B^was kept under a spray of c o l d water  after  refluxing.  The above method made i t p o s s i b l e t o keep the hydrocarbon from the a i r and other p o s s i b l e sources of  — 9 —  contamination d u r i n g p u r i f i c a t i o n .  The sources of contamin-  a t i o n were thus reduced to the apparatus i t s e l f , the reagents used, and subsequent  treatment of the hydrocarbon.  The f i r s t source was  e l i m i n a t e d i n s o f a r as p o s s i b l e  by c l e a n i n g the apparatus s u c c e s s i v e l y with dichromate t i o n , d i s t i l l e d water, and a c e t i c a c i d .  solu-  In order to e l i m i -  nate the p o s s i b i l i t y of contamination from the v a s s e l i n e  used  on the stopcocks, s e v e r a l l i t e r s of hot a c e t i c a c i d were drawn through a l l stopcocks,, before the hydrocarbon  was  introduced i n t o the f l a s k .  The second source of contamination, namely, the a c i d i t s e l f , c o u l d never be completely c o n t r o l l e d .  In the  case of one sample of 3 4 , the specimen being p u r i f i e d had a decidedly yellow tinge which was crystallizations.  not removed by  forty  The a c i d r e s i d u e s were removed s e v e r a l  times, but each time a f t e r s e v e r a l d i s t i l l a t i o n s the r e s i dues were yellow i n c o l o r .  In t h i s case i t was  that e i t h e r a l l the a c i d used was  contaminated,  manner decomposed upon repeated h e a t i n g . that t h i s p a r t i c u l a r sample of 3 4 was  I t may  suspected or i n some, be  mentioned  never obtained c o l o r -  l e s s , and i n the d i l a t o m e t e r gave a s e t t i n g p o i n t of 71.5::* which i s s e v e r a l degrees lower than the accepted v a l u e . ( c f p.38) The question arose as to whether or not t h i s method of p u r i f i c a t i o n could be used to advantage  on q u a n t i t i e s  of  m a t e r i a l greater than that s o l u b l e i n b o i l i n g a c e t i c a c i d . .  — 10-The r e f l u x i n g ensures intimate contact "between the hydrocarbon! and the a c i d , and i n s p i t e of the f a c t that i t was no longer a matter of -straight r e c r y s t a l l i z a t i o n , i t was b e l i e v e d that;: considerable q u a n t i t i e s of pure p a r a f f i n could be obtained by t h i s method r e g a r d l e s s of whether or not a l l the hydrocarbon a c t u a l l y had been taken i n t o s o l u t i o n and  crystallized:  out. EXPERIMENTAL PROCEDURES The apparatus and technique used by a l l i n v e s t i g a t o r s i n t h i s work have been e s s e n t i a l l y the same.  Fbr t h i s  reason only a rough o u t l i n e of,the equipment and procedure f o l l o w e d . i s given, except f o r those d e t a i l s which are c o n s i dered of importance and have not appeared  elsewhere.  Temperature Controls The constant-temperature bath used-*-^ consist&dl o f a large g l a s s c o n t a i n e r equipped w i t h ^ s t i r r e r , v a r i a b l e heating c o i l , tus  stand f o r d i l a t o m e t e r b u l b , c i r c u l a t i o n appara-i»  f o r c o l d water, f a c i l i t i e s  f o r keeping the l e v e l of: water  constant i n the bath, and thermoregulator. O r i g i n a l l y i t was tive liquid  the p r a c t i c e to change the s e n s i -  i n the thermoregulator b u l b whenever r e q u i r e d .  The author found i t more convenient to arrangd- a"complete s e r i e s of s e n s i t i v e l i q u i d s c o v e r i n g the range from 15-9.0°© In approximately 5°C; i n t e r v a l s .  Once made, these tubes could:  be placed i n the c i r c u i t whenever needed, and could be used  i n d e f i n i t e l y , thus saving on time and m a t e r i a l s . The  s e n s i t i v e l i q u i d c o n t r o l i s dependent upon baro-  metric pressure, and the temperature of the hath was  found to  f l u c t u a t e i f l e f t unattended^ hut by c a r e f u l manual c o n t r o l i t was  p o s s i b l e to maintain any temperature i n the range 20°~  80° to w i t h i n 1/50  of a degree f o r as long a p e r i o d as d e s i r e d .  The t o t a l range covered was  from 0-95 °®»  temperature obtainable with the bath used.  the h l g h e s t i  using a high  b o i l i n g - p o i n t l i q u i d i n the bath ( g l y c o l , f o r example) and with a s l i g h t m o d i f i c a t i o n of the dilatometer tubes to take care of the increased volume needed £or the added expansion of the hydrocarbon,. the density curves could be i n v e s t i g a t e d at higher  temperatures.  Dilatometer  Tubes;•  Some d i f f i c u l t y was  encountered i n p l a c i n g the  sample i n the dilatometer bulbs.. From a piece of  small-bore  t h i n - w a l l e d glass tubing i s drawn a t i n y funnel as shown. This funnel i s cut o f f to such a length as w i l l j u s t c l e a r the dilatometer bulb stem.  Figure I I  The bulb, funnel and cork are placed i n an oven atL 100°G^, and the l i q u i d sample i s poured i n . The e n t i r e u n i t i s withdrawn  from the bath with as l i t t l e disturbance as  p o s s i b l e and the hydrocarbon Is allowed t o s o l i d i f y . bath may be used i f necessary.  The f i l t e r  An ice:  i s then withdrawn,  i f p o s s i b l e i n such a manner that i t does not touch the w a l l s of the stem.  I f t h i s i s not p o s s i b l e , then a c e r t a i n amount  of hydrocarbon w i l l c l i n g t o the w a l l s of the d i l a t o m e t e r bulb stem.  To remove t h i s , the bulb i s i n v e r t e d  (freezing  the hydrocarbon i f i t i s l i q u i d at room temperature), and a--; small t w i s t of clean paper used to remove a l l t r a c e of hydrocarbon from the w a l l s .  During the course of t h i s and subse-  quent operations, the hydrocarbon should be p r o t e c t e d as much as p o s s i b l e from the atmosphere.  A complete d e s c r i p t i o n of the method o f p r e p a r i n g the d i l a t o m e t e r bulbs and tubes i s g i v e n by P a t t e r s o n . .  20  C a l i b r a t i o n o f the tubes: The theory of the determination of absolute d e n s i t y i s r e l a t i v e l y simple.  A weighed  sample o f pure hydrocarbon i s  p l a c e d i n a bulb attached t o a c a p i l l a r y stem.  A weighed  amount of Hg i s p l a c e d i n the remainder of the b u l b , and i t s height i s measured above a f i x e d r e f e r e n c e point on the stem at some f i x e d temperature.  T h i s gives us the weight of mercury  alone, and, the s p e c i f i c , volume of mercury being a c c u r a t e l y known, i t s volume at the temperature r e q u i r e d .  By removing  —13—  the hydrocarbon and r e p l a c i n g i t with mercury, measuring theheight a t the same temperature and making c o r r e c t i o n s for: the expansion  o f the g l a s s , we can o b t a i n the volume of the  mercury plus hydrocarbon.  S u b t r a c t i n g one from the other  gives the volume of hydrocarbon alone, and d i v i d i n g i n t o the weight gives the d e n s i t y .  By measuring c a p i l l a r y h e i g h t s a t v a r i o u s temperatures and making the necessary temperature-density  curves.  c a l c u l a t i o n s , we can o b t a i n  The shape o f the courve obtained  i n d i c a t e s the changes of c r y s t a l l i n e s t r u c t u r e with tempera*ture.  A sample o f the c a l c u l a t i o n necessary  for calibration  of the tubes and conversion o f c a p i l l a r y h e i g h t s t o d e n s i t i e s i s given i n Appendix I I . .  For the convenience of anyone who might be making: the same c a l c u l a t i o n s , which are somewhat t e d i o u s , the s p e c i f i c volume of mercury a t one degree i n t e r v a l s i n the range 0-100°C:is  given i n Appendix. I I I .  MELTING POINTS OF THE NORMAL STRAIGHT CHAIN HYDROCARBONS  Diiring the course temperature-density  of the i n v e s t i g a t i o n i n t o the  curves, i t was found  f e a s i b l e a t the same?  time t o study the m e l t i n g - p o i n t r e l a t i o n s h i p s of the normal straight-chain paraffin  series..  A survey of the l i t e r a t u r e r e v e a l s t h a t considerable? v a r i a t i o n may e x i s t i n the m e l t i n g - p o i n t values given f o r any h  I  •  was reached w i t h i n a few minutes, 'but not so i n the curves sections A-^-Bland B^-G:;. As the r e g i o n s of sharp t r a n s i t i o n were approached, the time r e q u i r e d f o r the mercury  level to  reach a constant value increased r a p i d l y . . In the •0.1-0.2°© i n t e r v a l between ti^., and  (that i s , a t a temperature  just  below the s e t t i n g point):. i t r e q u i r e d from one t o two weeks f o r e q u i l i b r i u m to be e s t a b l i s h e d .  During t h i s time i t was  necessary t o c o n t r o l the temperature as c l o s e l y as p o s s i b l e . In a c t u a l p r a c t i c e , due t o the n e c e s s i t y f o r l e a v i n g the bath unattended overnight, the temperature v a r i e d by as much  Temperature Figure I I I . When .the h i g h e s t p o s s i b l e mercury  l e v e l had been  reached, the temperature was lowered by s u i t a b l e increments,, readings taken, ..and the values p l o t t e d i n order t o provide a check on the previous curve.  It.was found that on a descend-  ing* temperature s c a l e , . the p o i n t GO f ;  o  r  any given sample?  The c a p i l l a r y heights, were p l o t t e d Immediately found.  T h i s was done f o r two reasons.  as  The c a p i l l a r y h e i g h t -  temperature  curves w i l l "be close i n shape to the d e n s i t y -  temperature  curve, .and t h e r e f o r e any discrepancy In the  latter latter:.  (due t o impurity, say) w i l l show up at once i n the F u r t h e r , the c a p i l l a r y h e i g h t - d e n s i t y curves show at:  a glance the temperature  at which any t r a n s i t i o n p o i n t s occur  and thus i n d i c a t e what regions must be r e i n v e s t i g a t e d .  The  'general method of o b t a i n i n g these curves f o l l o w s . A f t e r the tubes had been p l a c e d i n the constantt temperature bath, the h e i g h t . o f the mercury column i n the d i l a t o m e t e r stem, above a. f i x e d zeno c l i p , was p l o t t e d : against: temperature. , The general, form.of the curve obtained i s shown i n Figure III,,where Hi represented the f i r s t  transition  point .and C.'the second t r a n s i t i o n or m e l t i n g p o i n t . Readings were begun at.O°"Gj. t h i s temperature  The bath was kept at  u n t i l a constant r e a d i n g of the mercury  had been obtained;: the temperature was then r a i s e d  level  several  degrees and h e l d constant u n t i l e q u i l i b r i u m had been reached. The process was repeated at temperature  intervals  sufficiently  close together., to ensure a smooth and continuous curve.  The:  curve given i n Figure I I I i s an i d e a l i z e d form o f the curvefor. a l l members of the. aliphatHc, s e r i e s g r e a t e r than 18 and l e s s ..than 44. 1  In the regions AAA ,, B;-B?-, . and O G ^ j e q u i l i b r i u m  n  M e l t i n g P o i n t s . Observed', b.v; Hildebrandl Piper This Lab.  16  18? 20  36.4-  36:.55  22  44.0  44.0  24.  50.9  51.0  26'  56SO  57,0  56.4-56.6:  28  61.4.  62.0  61.4-61.55  29  6:3.5.  64.0  63.4-63.6  30  65.  V  66.0  65;. 6 - 6 5 " . 8  3.2  69.8  70  6 9 . 5 5 - 6 9 . V,  34.  72.9  :  73.5  Table I I . s e t t i n g p o i n t , obtained upon c o o l i n g , as d i s t i n g u i s h e d fronr the melting p o i n t , obtained.upon h e a t i n g , f o r purposes of e s t a b l i s h i n g the p u r i t y of the members under i n v e s t i g a t i o n . Where the exact.melting point was found t o be somewhatt indeterminate, or at l e a s t v a r i a b l e , with observer and r a t e o h e a t i n g , the s e t t i n g p o i n t , determined the f i r s t  by the appearance of.  c r y s t a l upon slow cooling', c o u l d be reproduced t o  w i t h i n ,0.2.-0.1°G3 f o r any one sample.  As can be seen from the  d e n s i t y temperature curves, the same t r a n s i t i o n values were obtained upon h e a t i n g or c o o l i n g with a l l members except; 16 and 1 8 , and i n the case of these, members the higher value i s taken as being i n best agreement with values obtained other sources..  from  one hydrocarbon.  0  Hildebrand and Wachter -; f o r example,  found that the melting-points recorded f o r 3 2 v a r i e d 68°C:.to7S°C:«  from  S e l e c t i n g the best values a v a i l a b l e i n the-  range 19 to 3 8 , they p l o t t e d the number of carbon atoms against the melting p o i n t , and from the r e s u l t i n g curve, suggested a set of values i n the range 19 to 3 6 . i s probably as s a t i s f a c t o r y as any,  T h i s method,  so long as the m e l t i n g  p o i n t s vary r e g u l a r l y with the number of carbon atoms, and provided there i s no a l t e r n a t i o n between the m e l t i n g p o i n t s of the odd and even members of the s e r i e s i n the range sidered.  I t was  con-  our purpose t o extend the above c o r r e l a t i o n ,  and to d i s c o v e r what i r r e g u l a r i t i e s , i f any,  existed.  The p u r i t y of the samples used i n t h i s work was f i r s t determined  by the constancy of the m e l t i n g - p o i n t , d e t e r 2 2  mined by the method of P i p e r *  The values obtained.are  given i n Table I I , together with the .corresponding values a c c o r d i n g to Hildebrand, and those given f o r the same membersby P i p e r . A l l the values obtained except that f o r 22 are lower than those suggested by Hildebrand, but they are i n good agreement with P i p e r ' s v a l u e s .  As p o i n t e d out by P i p e r  the slow h e a t i n g used i n h i s method, r e s u l t s i n values 0 . 4 o.7°  lower than those obtained by the u s u a l method of m e l t i n g  point determination.  In our work i t was  found a d v i s a b l e to use the  could be determined with an accuracy l i m i t e d only be the r i g i d i t y of temperature c o n t r o l , the accuracy of temperature measurement, and the patience of the observer. In  the case of 20, f o r example, an i n i t i a l  mination f i x e d point 03 between 3690J and 37°C'.  The  deter-  temperature  was r a i s e d to approximately 50°CT (that i s , w e l l above the melting p o i n t ) and readings retaken along C^-ffi. ature was  The  temper-  lowered by 0.1°C. increments below 37 G.:, and Gj was G  found to l i e between 36.2: and 3 6 . 3 ° 0 - . .  The temperature  was  once more r a i s e d w e l l above the m e l t i n g p o i n t and 0:'~ffi retraced.to 36.3°CC  The temperature of the bath was  held  1  constant.at 3 6 . 3 ° C f o r h a l f an. hour, d u r i n g which no change i n the mercury height could be observed.. The was  temperature  then powered".by 0.02°C: increments and kept constant at.  each p o i n t u n t i l i t was  c e r t a i n that the height d i d not  change..  /  This procedure was had been lowered to 36.22°G-;.  repeated u n t i l the temperature, While the temperature  was  dropping from 36.24- to 36.22°C_, the l e v e l i n the d i l a t o m e t e r tufee. wavered f o r a few seconds and then suddenly dropped. With the temperature b e i n g maintained at 36.22-36.20°G: f o r two days, c a p i l l a r y h e i g h t s were recorded at r e g u l a r  intervals  u n t i l e q u i l i b r i u m had been reached. Table I I I gives the values obtained j u s t below the f i r s t t r a n s i t i o n point  (,cf, p.. 14)  f o r 22, and these f i g u r e s  p l o t t e d i n Figure  IW.  C a p i l l a r y Height.  Time.  29.70  1 min  28.9.5.  2  28.42  5.  11 11  27.72  10  11 it  26.08  20  11  25.68..  30.  111!  24.80.'  40  lilt  24.10  5.0  III!  23.48?  60  III!  22.36.  80  fill  21.45  100  till  20.60  120  Utl  18/68. 17.34  J* r  <.i  3 hours 4:  11 11  16.20  5  15.03  6..'  14.75J  7.  ti  14.30  8  11  14.00  9  13.92  10  11  13.89  15  it  Table I I I  11  ti  200.,.  300 . 400 Time i n Minutes FI&URE IV.  500  600  It:.can be seen that considerable time i s r e q u i r e d ; f o r the hydrocarbon  t o reach e q u i l i b r i u m at the t r a n s i t i o n  p o i n t under,conditions of constant temperature.  The curve  i s assymptotic.to a c a p i l l a r y height of 1 3 . 8 5 cms, t h i s value representing equilibrium. determined  In the case of 2 0 , . p o i n t C was  three times, the values obtained agreeing w i t h i n  I / 5 0 of a degree CC.  T h i s point,, being f i x e d , , determinable  to a high degree of.accuracy, and e x a c t l y reproducable, i s taken as the s e t t i n g p o i n t f o r 2 0 . , The corresponding  values  thus found f o r the other hydrocarbons i n v e s t i g a t e d are given i n Table IV/..  n. 16-:;  S e t t i n g Point -  18.3'-'  18.  27.6'  20  36.2  22.  44. l'  24  50.77  26  55.8  28;  61.2  2.9:  63.2  30.  65.4.  32  69.5.  34:  72.9..  Table: IV/, As.has been;shown, these s e t t i n g p o i n t s are  r e p r o d u c i b l e with a high degree of coincidence f o r any g i v e n sample.  The same high degree of r e p r o d u c a b l l i t y i s not o b t a i n -  able, however,, with d i f f e r e n t specimens of the same member. In the case of 3 2 , f o r i n s t a n c e , two d i f f e r e n t samples from two d i f f e r e n t sources, supposedly  of an equal degree of p u r i t y  were used;, the melting p o i n t s found i n P i p e r ' s  apparatus  checked w i t h i n 0.2°Gj, but the s e t t i n g p o i n t s obtained by the d i l a t o m e t e r method v a r i e d by 0 . 5 ° 0 i  I t may be assumed t h a t  t h i d d i f f e r e n c e i n melting point was due to d i f f e r e n c e i n purity.  2 2 was s i m i l a r l y checked, u s i n g two samples made from  the'same a c i d by i d e n t i c a l methods of s y n t h e s i s , p u r i f i e d i n the same manner, and enclosed i n almost  i d e n t i c a l tubes, buH  even here the m e l t i n g p o i n t s v a r i e d by 0.2°G3,  It .was t h e r e f o r e assumed that the hydrocarbons were •not. s u f f i c i e n t l y pure t o warrant r e c o r d i n g t h e i r settings p o i n t s to w i t h i n more than 1 / 1 0 ° G j .  P a r t i c u l a r are was taken  i n the p u r i f i c a t i o n of theyhydrocarbon samples, but there  still  remains p o s s i b i l i t y of contamination... ...from the m a t e r i a l s used i n the s y n t h e s i s and not completely  removed d u r i n g  p u r i f i c a t i o n , from,the chemicals used i n p u r i f i c a t i o n , or p o s s i b l y introduced while s e t t i n g up the d i l a t o m e t e r b u l b s . Nevertheless, we b e l i e v e that the d i l a t o m e t e r method d e s c r i b e d here can be r e f i n e d t o provide means of determining  melting:  p o i n t s w i t h i n any d e s i r e d degree of refinement,  and should he  s e r i o u s l y considered as a means f o r determining  microanalyiii-  c a l l y the melting p o i n t s of: such homologous s e r i e s as the.:.  paraffins, fatty acids, alcohols, etc. A d e t e r m i n a t i o n o f t h e s e t t i n g p o i n t f o r 22 a s d e s c r i b e d above t o o k a t l e a s t two w e e k s , a n d t h i s f a c t w o u l d made t h e p r o c e d u r e a s o u t l i n e d p r o h i b i t i v e  i n many  cases.  However, a d i l a t o m e t e r - tub®-; s i m i l a r t o t h e one shown i n Figures-V/'might  be u s e d t o s h o r t e n c o n s i d e r a b l y t h e t i m e o f f  melting-point or s e t t i n g - p o i n t determination. The and  kept  to f i l l  sample t o be t e s t e d c o u l d be p l a c e d i n t h e bulb)  i n a m o l t e n s t a t e w h i l e t h e m e r c u r y was p o u r e d i n completely.the  b u l b and e n l a r g e d  stem.  The b u l b )  c o u l d t h e n be p l a c e d o n i c e , a n d - m e r c u r y added a s n e e d e d , so t h a t at.some r e f e r e n c e t e m p e r a t u r e , w o u l d be l e v e l w w i t h t h e g r a d u a t i o n  s a y 0°S^ t h e m e r c u r y on t h e d i l a t o m e t e r s t e m .  W i t h t h e stem i n s e r t e d a n d t h e m e r c u r y s e a l f i l l e d ,  t h e com-  p l e t e d d i l a t o m e t e r t u b e w o u l d be r e a d y t o be p l a c e d i n a constant  temperature bath.  I f t h e m e l t i n g p o i n t were known,  w i t h i n a d e g r e e o r s o , i t s h o u l d be p o s s i b l e t o d e t e r m i n e t r u e m e l t i n g p o i n t t o any d e s i r e d d e g r e e o f a c c u r a c y  7  the  within  a few h o u r s .  In c o r r e l a t i n g the m e l t i n g - p o i n t s o f the normal p a r a f f i n s e r i e s ^ , we a t t e m p t e d i n s o f a r a s p o s s i b l e t o s e l e c t . values  o b t a i n e d by one s e t o f w o r k e r s .  F o r t h i s p u r p o s e we •  have u s e d t h e s e l e c t e d v a l u e s  o f Deanesly and C a r l e t o n  t h e r a n g e 6-18, a n d o u r own f r o m 18-34.  5  for  F o r 4 0 , 5 0 , 60 a n d  70 we s e l e c t e d t h e m e l t i n g p o i n t s g i v e n b y G a r o t h e r s ^ - , a n d  < j r G a p i l l a r y stem, s m a l l  bore  rBulb  Capillary,  large bor  Calibrated  0  Ground'glass  P r o p o s e d D i l a t ometer Tube  joint;  f o r . , 3 6 , 5 2 , 6 2 , and 64, those of No  Gascard.^^  s i n g l e curve could he found to f i t the e n t i r e  s e r i e s , which i s -shown p l o t t e d as m e l t i n g p o i n t versus number of carbon atoms i n Figure V/K  Moullin  1 1  suggested  that the s i n g l e equation l o g ( n - 2 ) = 1 . 0 6 5 5 4" 5 • 9 t i / l 0 . 2 could, 2  be used.  From t h i s equation he  p o i n t s c a l c u l a t e d from 3 to 3 1 .  obtained values f o r meltingA comparison  with the values-,  from the I n t e r n a t i o n a l C r i t i c a l T a b l e s ^ . s e l e c t e d v a l u e s , together with M o u l l i n ' s c a l c u l a t e d m e l t i n g p o i n t s , i s g i v e n i n Table W. .  M o u l l i n suggests t h a t a d i s c o n t i n u i t y occurs at n=28, the l i n e being d i s p l a c e d approximately to  itself*  3°G3parallel  T h i s i s s c a r c e l y borne out by a comparison  the c a l c u l a t e d values with the suspect I n t e r n a t i o n a l  of Critical  Tables values given i n column 3> .even l e s s so with the ted  values given i n column 5«  selec-  o Yl = Y\o • C. oToms. FIGURE  VI  Table ru  m. p. (Calc'd)  *200 3 4 -1453 5 -111 6. - 87.5. 7i — 69.5; 8 • - 54.5 9 - 43.5 - 30.77 ii - 21..0 12 - 12 5 - 4.6 13 14. • - 2.7: 15. 9.3. 16: 16.3 21 17. 18 26.3 31.2 19 36 20 21 40.5 22 44.6. 4 8.6. 23 24 52.5 56.1 25. 59.6 26 63.O 27 66.2 28 29 69.3; 72.2 30 75. 31 32..  m. p. (1926IC.T) -190 -135 -131 - 94 - 90 - 56.5, - 51.0 - 32.0 - 26.5 - 12..b " - 6,21 5*5'. 10 20 25 28 32 38 40.4 . 44,4 47.8 51.0 54.0 60 59.5 65 '63.6.:. 66. 68  V/.  Dev. -10 -10 20 6.5 20.5 2 7.5.i  1.3 5.5 —0.5. 1.6 - 2.8 - 0.7 - 3.7 . - 1.5 - 1.7 - 0.8 - 2.0 0.1 0.2 0.9 1,5 2.1 - 0.4 3.5.. 1.2 5.7. J 6.2 7.0  m. p. (Selected)  -95.3: -90.6: -56.8 -53.7? -29.71 -25.6: - 9.6 - 6.0 5.5 10.0 18.1 22.0 28.0 31.4 36.2 40.4 44.0 47.0 50.6 . 53.3 55.8 59.1 61.2 6.3.2 65.4. 68.0  Dev.  7.8 21.1 2.3 10.2 -1..0 4.6" . -2.9 1.4 -2.8 -0.7?' -1.8 -1.0 -1.7 -0.2 -0.2 0.1 0.6 1.6 1.9 2.8 2.8 2,9 4.0 6,1 6.8 7.0  As shown i n f i g u r e ¥ 1 and as p o i n t e d out by 1  Tsakalotos and others^" ", the n-mp;curve i s i r r e g u l a r a t l e a s t as high as Gl . Tsakolotos proposed the equation 15 t = 85-0.01882(n-1) where n i s the number of carbon n-1 , 2  s  atoms and t i s the d i f f e r e n c e i n m e l t i n g p o i n t between n and the next.lowest  member of the s e r i e s .  As shown i n Table VI,  values c a l c u l a t e d from h i s equation are i n e x c e l l e n t agreement.  from 16 t o 35 with values taken from K r a f f t - ^ (from which the :  o r i g i n a l equation was d e r i v e d ) , and with the s i n g l e value of 6 0 taken from H e l l and Hagelle m. p... Tsak.Eqn. lo"  ;  17. 18 : 19 20 21 22 23  m. p Erafft  17.1  Dev?. -0.9 0.5 0.3 0.0  18? 22.5 28.0 3? 36^7?  • 23 27.7 32.0 36.2  40.1  •-Q.5'  40.4  24  50.4 .  25 26 27 28 29 30 31 32 33 34 35 36 60  53.5 56.4  -0,3. -0.7. -0.5 -0.7  44.4 47.7 51.1  43,7. '47.2  59.8 62.4  .  59.5  0.3  6B.1L 70.5 •'  0.3 0.7 .  74.7  2.3  64.9 67.3 69.0: 11*2 73.3 75.3 77.0 78.8 101.5  101.0-5  m. p. Selected". 18.1 22.0 28 . 0  31.4  36.2  40.4  44.0 47.0 50.6 53.3 55.8 59.1 61.2 63.2 : 65.4 68 69.55 72.0 73.5 75 76 4,98.9  Dew. -1.0 1.0 -0.3 -0.6 -0.0 -0.3 -0.3 0.2 -0.2 0.2 0.6 0.7 1.2 1.77 1.9 1.0 1.7/ 1.3: 1.8 2.0 2.8 2.6--  : ;  Table V.I  A comparison  of the calculated...values with those  s e l e c t e d i n t h i s work, however, shows t h a t although the agreement i s e x c e l l e n t from.,16 t o 2 5 , a d e f i n i t e and almost^constant d e v i a t i o n i s shown f o r members greater than 28.  Garner^,  from a p l o t of Q/T versus n and Q versus  n f o r the hydrocarbons  2 2 , 2 6 , 3 0 , 3 4 , obtained the  eauations s Q/T: - 0^001991n ~ 0.00404 andi Q = 0.6085n - 1.753 whene  Q «=> heat of t r a n s i t i o n  and  T = absolute temperature of t r a n s i t i o n .  E l i m i n a t i n g Q gives the equation: Tf - 0.6085n - 1..751: , 0.00149In - 0.00.404 He used t h i s equation to o b t a i n the s e t t i n g spoints of the hydrocarbons from 5 - 70.  The values thus c a l c u l a t e d are  compared with the f i n a l s e l e c t e d values ( c f page 3 8 ) i n Table VTI. C o n s i d e r i n g the small number of p a r a f f i n s used t o o b t a i n the equation, m e l t i n g p o i n t s d e r i v e d from i t are i n f a i r l y good agreement with the s e l e c t e d values the e n t i r e range.  throughout  In the case of the above members, i e 22,  26,, 30, and 34, agreement i s w i t h i n 0.2°C.  Figure M I against l o g ( n - 2 ) .  shows a p l o t of the s e l e c t e d values a  From F i g u r e VII four equations have been  obtained, and these equations, together with, the malting p o i n t s c a l c u l a t e d from"and the d i f f e r e n c e between s e l e c t e d and c a l c u l a t e d values are given i n the f o l l o w i n g s e c t i o n s .  -r30— n  m. p. Gale & 1  6 7 8. 9 10 11 12 13 14 15 165 17r 18 19. 20 22 26. 30 34. 353 36 40 50 54. 60 62 64. 70  ,  -126.7 - 99.1 >- 7 7 . 8 - 59.6 - 44.2 - 31.1 - 19.8. 9.9 - 1.3 6.4. 13.3 19.7. 25.O . 30.0 ; 34. 7/ 43.0 55.6 65.6.: 73,0 74.7. 76.2 81.6: 92.0 94.9 99.9 100.5 101.0 104.2  m. p.. Selected  Dev/.  -  -33.77 - 9.9 -21.1 - 5.5 -14.5 - 3.5, - 9.8 - 3.6' - 4.2 - 4.1 ~ 4.7. - 2.5 - 3.3 - 2.0 ~ 1.53 - 0.2 0.1 - 0.1 - 0.0 0.3. 0.6 1.6 1.4: 0.9 - 0.2 - 0.6' - 1.0 - 1.2  93: 89.7 56.7 54.1 29.77 27.6 10.0 6.3 5,5. 10.5; 18.0 22.5 28.3 32.0 36,2 43.2 44.4 65>7f 73.0 74.4 75.6 80.4, 90.6: 94.0 99 100.5 102 105.4-  Table  :  TO  The equation log(n-2) - 1.067 - 0.004l0t  was  found to c o r r e l a t e most s a t i s f a c t o r i l y the members 7 - 9 - 1 1 - 1 3 15-16..  d 2  n C\i Z5 cnGLr  -P-p - I CP  /_ O  - a o  ox •  o  0  o  o  (2-u)0l9oi  FIGURE VII  'n  IE. p. O'alc'd  m. p. Selected  -89.7  -90.6  0.9  -54.1  -53.7  -0.4  11  -27.6  -25.6  -2.0  13  - 6.25.  - 65.0  -0.3.  11.4  10.0  1.4  19.3  18.1  1.2  7 9  * "  15. 16.  -  dev.  Table V I I I  The c a l c u l a t e d ! values are f a i r l y c l o s e to the observed values, except i n the case of C - q . Members lower than 0^,, f o r both the odd and even members, are not i n c l u d e d , as the d e v i a t i o n o f observed from c a l c u l a t e d m e l t i n g p o i n t s are too g r e a t . For the even members 6.-8-10-12-14-16, the best: equation was found t o be log(n-2) =• 1 . 0 5 1 — n.  0.0048lt.  m. p» Calc'd.  m.p.. Selected:  65  -93.3  -95.3  8  -56.7  10  -29.7  -30.8  -1.1  1.2 .  -  -10.6  -1.1  9.6  •  -56.8:  14.  5.5  5.2  16:  19.3  18.-1  Table IX  dev/. 2.0 0.1  0.35 1.5  Here again the c o r r e l a t i o n i s f a i r l y from  1941  The  e d i t i o n of Hydrocarbon  good, apart  C o n s t a n t s ^ ^ giv.es  the m e l t i n g p o i n t of Cg'-to be -94.5, which would reduce the d e v i a t i o n t o 1.2 C, but there i s no reason to assume that, 0  10  t h i s l a t t e r v a l u e , taken from Parks -, Is any more r e l i a b l e than t h a t . o f - 9 5 . 3 , obtained by I t may  2  Shepard ^".  be noted i n r e f e r e n c e to the m e l t i n g - p o i n t s  recorded by Deanesly and C a r e l t o n , that. C^g, was  used as a  r e f e r e n c e p o i n t , and that the p r o p e r t i e s of both C]_2  were c a r e f u l l y checked by them.  values f o r C_ = 0.003;.  12  G^and'  Their melting-point  were -9.6o4°C =-0.003,. and f o r G ^ . 18.145°G  I t .is p o s s i b l e to o b t a i n an equation a p p l i c a b l e  to 1 0 - 1 2 - l 4 - a n d 1 6 ,  g i v i n g d e v i a t i o n s from observed values  of l e s s than 0.5°C, but G^^would then be c a l c u l a t e d 3.5.°G. too high.  From F i g u r e VII i t can be seen that three of the l i n e s  converge  i n the neighborhood  of C-j_ga . Assuming t h a t the break  from one curve to another i s not sharp,\ as shown, then the c a l c u l a t e d m e l t i n g - p o i n t s f o r G^g-, G^y;/ and G-iq w i l l be too high.  As shown i n Table X, ..these three values are a l l c a l c u -  l a t e d too high.. The range C^g to 0 ^ 4 i s covered by the equation log(n-2) All  1.02  - 0.0065t  of the. c a l c u l a t e d values between 19  and: 2 9 are  too low, and an equation can be obtained f o r this: range with a maximum d e v i a t i o n of 0.5°  T  as. shown i n Table XI .  - 3 4 -  n.  m. p. Galc'd  m. p. Observed 18.145 22.0 28.0 31.4 36.2 40.4 44.0 47.0  16-. 19.4: 17 . , 24.0 18 28.3: 32.4. 19 20 36.2 21 39.8: 22. 43.2 23. 46.5 24 . 49.6 25 52.5 26  27. 28 : 29 30  i 31 32  33 34. 35  • dev.  1.3 2.0 0.3 1.2 -0.0 -0.6-; -0.8 -0.5 -1.0 -0.8 -0.4 -1.0 -0.55 -0.0 0.3 0.1 0.8 0.5 1.1 2.1  50.66  53.3 55.8 59.1 61.2 63.2 65.4 68 69.5 72.0 73.5 75,0  55*4. 58.1 60.7 63.3 65.7 68.1 70.3 72.5 74.6 76.6  Table X.  n  dev.. 0.5  20 21 22  —0.1 -0.3 -0.00  23  24. 255  -0.5 -0.3.  26::  0.1  27;  -0.5  28.  -0.0  29  0.5,  -0.®  30 31 32  -0.6: -1.3  Table XI However, the data used f o r the c a l c u l a t i o n s i s not considered s u f f i c i e n t l y r e l i a b l e  shown i n Table XI  t o draw any  conclusions from.the small d e v i a t i o n s thus  obtained.  For the remainder of the s e r i e s , from 3 3 up t o 7 0 , , was  d e r i v e d the equation: log(n-2) = 1,02 n  m. p», Calc'd  28 29  64.0  $5>65 67.2 68.7 70.2  30 31  32 .  33 34. 35; 365 377 38.. 39 40  71.67  73.0 74.4. 75:. 6 7 76.9 78.0: 79.2 80.4 81.5  41 42  82.65  437 44  83.6 84.8 90.6 94.0 98.7 100.2 102.2 105.4.  5P  54 60  62 64. 70  . - 0.0065t. m. p. Observed 7  61.2 63.3... 66.4, 68\ 69.5 72.0 72.9 75, 765 76.4 77.6? 78.8? 80.7? 81.77 82.9 83.8 86.4. 92.1 95.0 98.9 100.5 102.0 105.3  Ref.  «•#  *•»  365 8  7  8 8 '3535? 3535. 35357  37 37  3535. 35355' 35357 3 35 7? 3 3. 7 7 3 T( 77 3 3 li 3  Dev. 2.8 2.4 1.8  0.7 0.7  -0.4 0.1 -0.6" -0.4 0.5 0.4 0.4 -0.3  -0.£  -0.35 -0.2 -1.6  -1.5  -1.0 -0.2 -0.3 0.2 33,1  Values obtained i n t h i s l a b o r a t o r y . Table The  XII  closeness of the agreement to a general  i n t h i s range i s r a t h e r s u r p r i s i n g .  equation  4 4 and 5 0 show appreciable  d e v i a t i o n , but out of 2 0 m e l t i n g p o i n t s compared, s e l e c t e d from h a l f a dozen o r i g i n a l sources, twelve i n 0.4°C  of the c a l c u l a t e d value, and 17  of them are w i t h -  are w i t h i n 0 . 7 ° C  The apparent  smoothness of t h i s curve i s a l l the more  remarkable when i t i s considered how  l i t t l e work has been  done on the higher members of the a l i p h a t i c hydrocarbons s e r i e s , and how  difficult  i t i s to o b t a i n the i n d i v i d u a l mem<  bers i n the pure form.  Included among the various attempts made to f i n d r e l a t i o n s h i p s between the molecular weights and m e l t i n g p o i n t s of homologous s e r i e s , Austen!- proposes the equation: log M = A  -  4t/l0  4  where A i s a constant dependent upon the s e r i e s Table X I I I givds the value of A f o r the p a r a f f i n  considered. series.,  c a l c u l a t e d f o r the m e l t i n g p o i n t s shown. n.  m.  20 22  36.2 44.1 : 50.7 55.8 61.2 63.2 $5.4 69.8  24. 26 28 29 30 32  1  p.  A/.. 2.3055 2.3160 2.3269  2.3400 2.3510 2.3580 2.3640 2.3750  Table X I I I The p l o t of A-n. shown i n F i g u r e VIII shows that the v a r i a t i o n of the constant i s l i n e a r with the. range consideredand Austen's equation becomest l o g M = A - Ht - 4 t / l o \  . where B i s another  This equation, s i m i l a r to a l l others proposed  f o r homologous  s e r i e s , holds good only over a l i m i t e d range of the series.  constant.  total  From the foregoing data and c u r v e - f i t t i n g , we suggest the f o l l o w i n g values  f o r the melting p o i n t s o f the  normal s t r a i g h t - c h a i n hydrocarbon members. n  mp.  dev.  6 -93.0 7 -89.7 8- -56.7 -54.1 9 10 . - 2 9 . 7 11 -27,6 ; 12 -10.0 - 6.3 13 14 . 5.5 10.5 15:;. 16 18.0 17 22.5 18 28.3 32.0 19 20 36.2 21 • 39.8 22; 43.2 23 46.5 24 49.6. 25. 52.5  1.0 0.5 0.3 0.3 0.5 1.0 0.5 0.3 0.3 0.5 0.2 0.5 0.3 0.5 0.2 0.4 0.5 0.5 0.5 0.5  n  mp.  dev.  • • 26 .55.5 0,3 58.1 27. 0.5? 28 60.7, 0.5 j 29 0.3 63.3 • !30 65.7 0.3 ! 31 68.0 0.3 32 70.0 0.5 0.4 33 71.6 34 73.0 0.4 0.4 : 35. 74.4 0.4 36 75.6 0.4 37. 76.9 0.4 38 78.0 79.2 0.4. 39 40 80.4 . 0 . 4 41 81.5 0.4 42. 82.6" 0.3 43 83.7 0.3 44 84.8 0.3 45 :  J  ;  n  mp.  dev.  90.6:  0.2  94.0  0.2  60  99.0  0.2  61 62  100.55  0.2  102  0.2  105.4  0.2  46 47 48 49 50  51  52 53  54. 55 56'  57 58 59 •;  63  64 65;  66 67 68 69  70 Table XIW General Theory The  normal a l i p h a t i c hydrocarbons being  symmetrical and uninfluenced  completely  by the presence of p o l a r groups,  lend themselves t o a study of atomic s t r u c t u r e and molecular ' measurements. Muller^  ± u  X-ray s t u d i e s on the s e r i e s , made.by S a v i l l e ^ S ,  , P i p e r " , and others, have e s t a b l i s h e d the f a c t  that many members of the p a r a f f i n s e r i e s e x i s t i n s e v e r a l e n a n t i o t r o p i c forms.. These s t u d i e s have shown that at the  point of t r a n s i t i o n  from,one c r y s t a l l i n e f o r m t o a n o t h e r ,  t h e r e i s a l a r g e change i n t h e 001 l a t t i c e relatively  spacings w i t h a  s m a l l change i n t h e a r e a o f t h e b a s a l  plane.  T h a t i s t o s a y , in- t h e change f r o m one f o r m t o a n o t h e r :  there  i s a change i n the. d e n s i t y . : B e c a u s e o f t h i s f a c t , t h e d e n s i t y changes c a n be u t i l i z e d i n t h e d e t e r m i n a t i o n temperature a t which t r a n s i t i o n  occurs.  of the  One o f t h e o b j e c t s  o f t h i s work was a u s e o f t h e d i l a t o m e t r i c measurements a s a means o f t h r o w i n g  some l i g h t on t h e c o m p l e x  crystalline  s t r u c t u r e a n d c r y s t a l changes o f t h e p a r a f f i n s , a s w e l l a s to  f i n d some r e l a t i o n s h i p b e i n g d e n s i t y change a n d  crystalline  form.  T h e r e a p p e a r s t o be g e n e r a l a g r e e m e n t t h a t t h e a l i p h a t i c hydrocarbons e x i s t  i n at least three  crystalline  forms,: A form.  ••••  The c h a i n a x i s i s v e r t i c a l t o t h e 001 p l a n e , a n d t h e p l a n a r s p a c i n g s ' a r e a d i r e c t measure o f t h e l e n g t h o f t h e molecules.  E v e n members o f 18 o r more c a r b o n atoms a n d  odd members o f 11 o r more c a r b o n atoms show t h i s  form  near t h e m e l t i n g p o i n t ( t h a t i s , i n t h e t r a n s i t i o n r e g i o n ) . Muller -^ gives the f o l l o w i n g 001 spacings: 1  n  A.units  26  34.95 36.38 37 38.68 40.5 41.5 42.33 45-5 46.64 47.5  27  28 29 30 31 32  34 • 35 36  T a b l e XV/ Prom t h e above d a t a i t can,be s e e n t h a t t h e s p a c i n g s a r e a d i r e c t measurement o f t h e c h a i n l e n g t h . B,form:  Even-numbered p a r a f f i n s up t o 24 a t n o r m a l t e m p e r a t u r e s c r y s t a l l i z e w i t h t h e c h a i n axes i n c l i n e d a t a constant a n g l e t o t h e 001 p l a n e . Muller,  The s p a c i n g s , a s g i v e n by ,  a r e given i n Table  XVI.  r  ,  —41—  n.  units'  26 28 32 34 36  31 33.25 37.8 39.86 42.33  Table The  001  XVI  spacings of t h i s m o d i f i c a t i o n are  t h a n t h e A f o r m of t h e . t r a n s i t i o n r e g i o n . t h e h y d r o c a r b o n s resume t h e B C  On c o o l i n g ,  form.  form:  26  i s the only hydrocarbon  and t h e v a l u e o f the 0 0 1 it  shorter  t h a t shows a l l t h r e e  s p a c i n g i s g i v e n ad 32.6:, t h a t i s ,  shows a v a l u e , l y i n g b e t w e e n t h e o t h e r two  A f o r m ' i s s u p p o s e d t o be numbered members n o r m a l l y  spacings.  t h a t form i n t o which.the crystallize.  The  members c r y s t a l l i z e w i t h a t i l t e d C f o r m ,  and  T h i s i s b o r n e out by  temperature-density  o b t a i n e d f o r 29  as c o n t r a s t e d w i t h t h e c u r v e s  The  odd-  even-numbered  t r a n s i t i o n temperature. curve  forms,  show a h i g h e r the  ( c f page  68  )}  o b t a i n e d f o r t h e e v e n members.  —42  —  Odd-numbered p a r a f f i n s , n e v e r assume t h e C f o r m . I n o u r -work i t was f o u n d t h a t w i t h some members t h e d e n s i t y c u r v e o b t a i n e d upon h e a t i n g d i f f e r e d f r o m 1  o b t a i n e d upon c o o l i n g . spacings;  Muller -^ obtained values f o r the long  i e , t h o s e . s p a c i n g s d e p e n d e n t m a i n l y on t h e l e n g t h Two s u c h v a l u e s were r e c o r d e d f o r 18  of t h e carbon c h a i n . and 2 0 .  that  A s i m i l a r phenomenon o c c u r s w i t h 2 2 , v a l u e s f o r  which are not given.  The  .' n  d  18  25.3  23.3  20  27.4  25.4  l  V  c o n n e c t i o n i s n o t a p p a r e n t , b u t t h e above s p a c i n g s  may a c c o u n t f o r t h e f a c t t h a t 20 a n d 22 e x h i b i t t h e same g e n e r a l d e n s i t y - t e m p e r a t u r e . c h a r a c t e r i s t i c s as 24, 26, e t c . , on a r i s i n g t e m p e r a t u r e  s c a l e , a n d t h e y p o s s e s s t h e same  f o r m a s t h e l o w e r even-numbered members on a d e c r e a s i n g temperature  scale .  As t h e h y d r o c a r b o n s 60°,  are heated 0 ( F i g u r e IX) approaches  s h o w i n g h e x a g o n a l c l o s e p a c k i n g above t h e m e l t i n g p o i n t .  18 a n d 20 do n o t r e a c h t h e s t a t e a t t h e m e l t i n g p o i n t , w h e r e a s 22 d o e s . an e x t r e m e  This l i q u i d c r y s t a l l i n e  c o n d i t i o n may be  c a s e o f m o l e c u l a r space a r r a n g e m e n t 2  i n liquids,  as s u g g e s t e d by S t e w a r t ^ i n h i s p a p e r d e a l i n g w i t h c y b o t a x i s  a-a Figure IX It  i s p o s s i b l e t h a t above t h e m e l t i n g p o i n t t h e h e x a g o n a l  c r y s t a l arrangement o f t h e p a r a f f i n molecules  increases  w i t h t e m p e r a t u r e , a n d , on a p p r o a c h i n g t h e b o i l i n g the c r y s t a l l i n e  point,  s t a t e g i v e s way i n a r e g u l a r m manner t o a  s t a t e o f random m o l e c u l a r A relatively  distribution.  s i m p l e i n t e r p r e t a t i o n c a n be made o f t h e  change i n d e n s i t y a t t h e t r a n s i t i o n p o i n t .  The h y d r o c a r b o n  e x i s t s i n t h e s o l i d s t a t e a s c r y s t a l s o f t h e B f o r m . ;;»'.>•  When i t i s h e a t e d , t h e o n l y increase  i n t h e 001 s p a c i n g .  change i s a r e g u l a r  When t h e f i r s t  p o i n t i s r e a c h e d , t h e p i c t u r e becomes.  transition  t h e volume o c c u p i e d  p e r m o l e c u l e i n c r e a s e s r a p i d l y , and  there i s a sharp decrease i n d e n s i t y . transition region a r i s e  Throughout the  i n t e m p e r a t u r e i s marked Toy  c u b i c a l e x p a n s i o n o n l y , w i t h no change i n c r y s t a l l i n e structure  ( a t l e a s t no s t r u c t u r a l change m e a s u r e a b l y  e f f e c t i n g the temperature). a uniform,  At. t h e m e l t i n g p o i n t t h e r e i s  r a p i d change t o t h e h e x a g o n a l c l o s e  packing  above t h e m e l t i n g p o i n t , and a t t h e m e l t i n g p o i n t t h e r e i s a r a p i d decrease i n d e n s i t y .  I n t h e c a s e o f 20 and 2 2 , where no t r a n s i t i o n  was  o b t a i n e d upon h e a t i n g , t h e C f o r m p a s s e s o v e r i n t o t h e hexagonal form of the l i q u i d s t a t e .  Upon c o o l i n g f r o m t h e  l i q u i d s t a t e , a l l members above 16" show t h e two This subject w i l l  transitions.  be d e a l t w i t h a t g r e a t e r l e n g t h i n t h e  d i s c u s s i o n of the i n d i v i d u a l hydrocarbons. • • F o r t h e even-numbered p a r a f f i n s g r e a t e r t h a n 1 6 , . as they are c o o l e d from the l i q u i d s t a t e , c r y s t a l l i z a t i o n takes p l a c e i n the normal or A-form.  first  This A form c o n t r a c t s  __45~  w i t h r e g u l a r l y i n c r e a s i n g d e n s i t y u n t i l the second point i s reached.  transition  I t has n o t y e t been determined e x a c t l y  what change i n t h e i n t e r m o l e c u l a r a n d i n t r a m o l e c u l a r forees  i n v o l v e d causes t h i s  change i n t o t h e s t a b l e A f o r m .  As t h e t e m p e r a t u r e d e c r e a s e s t h e d e n s i t y i n c r e a s e s , t h e m o l e c u l e s come c l o s e r t o g e t h e r ,  the forces of  cohesion  i n c r e a s e , and a t the t r a n s i t i o n p o i n t the e q u i l i b r i u m e x i s t i n g before  between t h e s e f o r c e s i s d e s t r o y e d  and  another c r y s t a l l i n e form appears, e i t h e r the B form or 0 form w i t h t i l t e d a x i s . According  to P i p e r  2 2  and K o l v o o r t ^ , the lower  t r a n s i t i o n p o i n t i s more s t r o n g l y a f f e c t e d by than the upper.  This  contamination  i s l o g i c a l i n view o f the d e l i c a t e  e q u i l i b r i u m e x i s t i n g between o p p o s i n g m o l e c u l a r  forces.  RESULTS Following are the r e s u l t s obtained.  I n t h e case  of each i n d i v i d u a l hydrocarbon a graph i s i n c l u d e d , w i t h a d i s c u s s i o n of the curve.  I n order  t o c u t down  t h e m a i n body o f t h i s w o r k , t h e a c t u a l d e n s i t i e s a r e given i n Appendix IV.  together  --46--  Hexadecane The 53),  first  sample  tested  known t o he impure  hut f o r purposes of comparing  i t w i t h o t h e r members  o f t h e s e r i e s , i t was d e c i d e d t o make t h e d e n s i t y No t r a n s i t i o n c o m p a r a b l e was f o u n d .  calculations.  t o t h a t f o u n d i n t h e h i g h e r members  A s s e e n f r o m F i g u r e X, two s e p a r a t e c u r v e s were  obtained i n the s o l i d  The  state.  exa,ct c o n d i t i o n s by w h i c h  one f o r m i s c o n v e r t e d  i n t o t h e o t h e r c o u l d n o t be d e t e r m i n e d .  The l o w e r  (A) was. o b t a i n e d a t l e a s t t w i c e w i t h t h e t e m p e r a t u r e down.  ( c f page  A r e g i o n o f i n s t a b i l i t y was e n c o u n t e r e d w i t h  section going rising  t e m p e r a t u r e a t 1 2 - 1 3 ° G , a n d i n a n e f f o r t t o f i n d a smooth c u r v e i n t h i s p a r t i c u l a r r e g i o n , t h e t e m p e r a t u r e was h e l d c o n s t a n t f o r as l o n g a time as p o s s i b l e . was s e t a t 1 2 . 5 ° C one n i g h t ; still  12,5°C, and t h e mercury  c o r r e s p o n d i n g to. c u r v e B.  The t e m p e r a t u r e  the f o l l o w i n g morning l e v e l had dropped  P o i n t s on t h i s s e c o n d  i t was  to a point curve  were o b t a i n e d f r o m 1 2 . 5 down t o o°C, a n d b a c k up t o t h e m e l t i n g p o i n t , b u t i t was n o t p o s s i b l e t o d u p l i c a t e  this  curve.  A smooth c u r v e  (B) c o u l d be p l o t t e d f r o m t h e m e l t i n g -  p o i n t down t o 0°C a n d f r o m 0 - 1 2 ° C a n d r e c h e c k e d w i t h good r e s u l t s , b u t f r o m 12°C t o t h e m e l t i n g p o i n t , r e a d i n g s c o u l d n o t be o b t a i n e d .  consistent  It had  s h o u l d be e m p h a s i z e d t h a t t h i s p a r t i c u l a r  o b v i o u s l y become c o n t a m i n a t e d .  sample  I t was somewhat y e l l o w  i n c o l o r , gave a m e l t i n g p o i n t a t l e a s t 2 d e g r e e s t o o l o w , and was o n l y u s e d b e c a u s e a t t h e t i m e no o t h e r available. liquid exact  Nevertheless,  values  f o r the density i n the  s t a t e a r e i n good a g r e e m e n t w i t h v a l u e s measurement.  For instance,  o b t a i n e d by  Deanesley^ gives the  d e n s i t y o f h e x a d e c a n e a t 20°G a s 0 . 7 7 3 3 5 , was  s p e c i m a n was  and our value  0.7736.  Evidently sufficient  impurity to a l t e r the melting  p o i n t by s e v e r a l d e g r e e s i s n o t s u f f i c i e n t t o c a u s e any marked change i n . t h e d e n s i t y .  A s e c o n d sample o f h e x a d e c a n e , o b t a i n e d  from the S h e l l  O i l D e v e l o p m e n t Company was i n v e s t i g a t e d , a n d was f o u n d t o have a m e l t i n g p o i n t o f 1 8 . 3 ° C a n d a s e t t i n g p o i n t o f l6.6°C. At the time of w r i t i n g the d e n s i t y c a l c u l a t i o n s f o r t h i s sample have n o t b e e n made, b u t a r o u g h c a l c u l a t i o n  places  t h e d e n s i t y o f t h e s o l i d p h a s e ( f o r w h i c h o n l y one c u r v e was o b t a i n e d ) i n t h e n e i g h b o r h o o d o f A r a t h e r t h a n B.  Sicosane: W i t h t h e even-numbered p a r a f f i n s b e l o w 26, i n t h e  solid  s t a t e , t h e y assume t h e B f o r m , w i t h a s p a c i n g b e t w e e n t h a t o f t h e C and A f o r m , a a c o r d i n g t o Muller...  I t does n o t  e v i d e n t on t h e o r e t i c a l g r o u n d s t h a t t h e s e 001  spacings  taken- as a d i r e c t measurement o f t h e d e n s i t i e s ; evidence  Qualitatively,  temperature  i n t h o s e r e g i o n s c l o s e t o the  should f a l l  t h e A f o r m and t h o s e  n.  direct  densities  transition  somewhere b e t w e e n t h e d e n s i t i e s i n  of the C form.  \  (l) Density 2°C b e l o w t r a n s  n.  16  0.899  20  0.909  22  0.906  Table  . (2) D e n s i t y 2° below trans..  30  0.876  32  0.873  34  0.879  n.  (3) D e n s i t y 2 ° below, t r a n s .  30  0.924  32  0.923  34  0.923  XVII  be  i t i s indicated.  I f the assumption i s t r u e , t h e n the v a l u e s o f the f o r 20, 2 2 , 24,  can  t h a t i s , as  t o p r o v e t h a t t h e d e n s i t y measurements a r e a  f u n c t i o n of these s p a c i n g s .  appear  —50—  (l) w i l l and  c o r r e s p o n d t o t h e B f o r m , (2). t o t h e A f o r m ,  ( 3 ) t o the, C f o r m . - The c o r r e l a t i o n a p p e a r s good f o r t h e s e members, b u t  i n t h e case o f 24, t h e B form i s a c t u a l l y h i g h e r f o r the C form, r a t h e r than lower.  than  that  I f t h e above a s s u m p t i o n  were c o r r e c t , n a m e l y , t h a t t h e A, B, and C c r y s t a l l i n e  forms  were a f u n c t i o n o f t h e s e c t i o n s  then  the  solid region  of the density  f o r 2 6 , 2 8 , 32 and 3 4 s h o u l d  curves,  l i e i n one  r e g i o n , t h o s e f o r 1 8 , 2 0 , 2 2 , and 24 i n a n o t h e r , a n d t h e t r a n s i t i o n points  f o r 26, 28, 32, 34, i n s t i l l  Whether t h i s i s s o , o r w h e t h e r t h e d e n s i t y  another.  f o r a l l even  members o f t h e s e r i e s f r o m 16 t o 3 4 a t 0°C s h o u l d a proportional increase with increase not  certain.  i n chain  show  length, i s  T e m p e r a t u r e i n °QFIGURE X I  Docosane: Considerable good r e a d i n g s temperatures. t u r e , and  d i f f i c u l t y was  f o r t h i s sample, p a r t i c u l a r l y No  t r a n s i t i o n was  obtained  s c o p e , was  line  ascending,  on r i s i n g t e m p e r a -  s e e n t o q u i v e r , and  were o b t a i n e d  of  10°C.below t h e m e l t i n g p o i n t .  m e r c u r y s u r f a c e , as v i e w e d t h r o u g h t h e  readings  for  there appeared a tendency towards d i s t u r b a n c e  e q u i l i b r i u m at approximately The  encountered i n o b t a i n i n g  cathatometer  i n t h i s temperature  region  at d i s t a n c e s c o n s i d e r a b l y below  the  shown.  .In.-.. 3 -samples, 20,  22,, and  particularly  r e g i o n ( i n a l l cases approximately  10°C  26,  below the  t h e r e was  from the p o i n t s o b t a i n e d  on r i s i n g t e m p e r a t u r e .  As  drawn  mentioned  i n t h e n o t e on m e l t i n g p o i n t s , c e r t a i n s e c t i o n s o f t h e curves, mainly  i n t h e l i q u i d r e g i o n , c o u l d , w i t h any  d u p l i c a t e d any  r a c y of the  number o f t i m e s w i t h i n t h e  instruments  used.  A l l transition  s e n s i t i v e t o t e m p e r a t u r e c h a n g e , and c a s e o f 22 and It of the  one  regions  sample-  accuare  so i n t h e  26.  i s b e l i e v e d t h a t t h e p o i n t s l y i n g on t h e s e  curves  density  l i m i t of  particularly  a  melting  p o i n t ) where a c o n s i s t e n t l y s m o o t h ; c u r v e c o u l d n o t be  be  tele-  are not r e l i a b l e .  considered  are d o t t e d , although  included.  .The  considered  t o be  The  sections  p a r t s o f . t h e curve  t h e d e n s i t y v a l u e s have b e e n  s e c t i o n s i n heavy l i n e s are r e p r o d u c i b l e reliable.  The  so  dotted regions w i l l  bear  and  —53—  f u r t h e r i n v e s t i g a t i o n , e m p l o y i n g a more r i g o r o u s method o f temperature  c o n t r o l over a longer p e r i o d of t i m e .  Te^raoos^Mj B e f o r e d i s c u s s i n g the curve o b t a i n e d f o r 2 4 , . i t  might  be p e r t i n e n t , a t t h i s p o i n t t o g i v e a resume^ o f a r e c e n t / 0  a r t i c l e by K o l v o o r t - ' o n t h e c r y s t a l l i n e homologue.  s t r u c t u r e of. t h i s  He u s e d a sample o f s e t t i n g - p o i n t e q u a l t o 50.B,  a value almost i d e n t i c a l w i t h t h a t found i n t h i s  ;  laboratory,.  By e x - r a y m e a s u r e m e n t s , K o l v o o r t f o u n d two t r a n s i t i o n  points  and t h r e e c r y s t a l l i n e s f o r m s , g i v e n b e l o w . :  Form  Range  Transition  50.8-46-  50-. 8}  bo.  46  46  CV.  below  -41 41  Temperature  41  l)ablefXVlIT[li He  s u g g e s t s t h a t ; t h e c f o r m i s m o n o c l i n i c , Upon h e a t i n g  i t p a s s e s o v e r i n t o t h e o r t h o r h o m b i c bo f o r m , r e t a i n i n g  the  o r i e n t a t i o n of the m o l e c u l e s w i t h r e s p e c t t o each o t h e r i n t h e 001 p l a n e .  The  o r i g i n a l l y t i l t e d molecule i n - t h e c form  t a k e s up a p o s i t i o n p e r p e n d i c u l a r t o t h e 001 p l a n e w i t h  no  r o t a t i o n o f t h e zigzag?, m o l e c u l e s .above t h e i r l o n g i t u d i n a l axes.. K o l v o o r t ..made a d i l a t o m e t r i c i n v e s t i g a t i o n o f t h e and f o u n d t h a t . i n t h e change f r o m . t h e  c t o the b.form,  marked change t o o k p l a c e i n t h e d e n s i t y . was  No d e n s i t y  sample,, a  change  o b s e r v a b l e i n the t r a n s f o r m a t i o n from the c t o the a  I n the c form the angle between.the  o p t i c a l axes  form.  decreases  within-,0.3  d e g r e e s b y 20/£ o f i t s f o r m e r v a l u e .  I n t h e b: f orm  t h e a x i a l a n g l e g r e a t l y depends on t h e t e m p e r a t u r e up t o t h e point  o f t r a n s i t i o n f r o m t h e b t o t h e a f o r m a t 46, a t w h i c h  p o i n t the f i g u r e f o r u n i a x i a l c r y s t a l s i s formed. m e l t i n g p o i n t , the c r y s t a l remains  uniaxial.  d u l l e r n o t e s t h a t a change t a k e s The  a and b , a x e s  alter their  Up t o t h e  place  f i r s t with  24.  l e n g t h as the temperature i n -  c r e a s e s , J u s t a s t h e y d i d i n t h e c a s e o f 20 a n d 22, b u t when a c e r t a i n temperature has been r e a c h e d ( c o r r e s p o n d i n g transition point),:there  t o the  i s a s u d d e n change i n s t r u c t u r e .  t e m p e r a t u r e o f t h i s t r a n s i t i o n i s g i v e n as 4 0 - 4 1 .  The;  Assuming-  t h a t t h i s v a l u e i s t h e t r a n s i t i o n . p o i n t , we -have t h e t h r e e following  values? Transition  Point.  There  from a  Kolvoort -  40-41  Muller ^-'  47.9.  This  0  obtained  sample  one v a l u e  known t o be  For  5  1  Labi  XIX:  i s no a p p a r e n t e x p l a n a t i o n  change i n d e n s i t y t a k e s 46.4,  Source  41  Table  Kolvoort  '-  f o r t h i s wide v a r i a t i o n - .  of.. 36°G. f o r t h i s t r a n s i t i o n  impure.  place  w h i c h w o u l d be i n f a i r l y  I t i s possible that  a t the f i r s t  transition,.  good a g r e e m e n t w i t h  our  comparison, 3 i n t e r p r e t a t i o n s of the c r y s t a l l i n e  of: o c t a c o s a n e a r e g i v e n  i n Figure  XIW.  point, the 45.8value.  changes  Millar solid  orthorhomblc or triclinic  hexagonal  tr,pt. transition  m.p.  liquid.  Piperr_B^£orai molecule obliaue to 001 t,  A form molecule^ 1 001  m.Kolvoort monoclinic orthorhombic ipseudohexagonal  m.p,  FIGURE XIV  hexagonal  - 5 8 -  Temperatu're "m F i g u r e XV  Hexacosane; Two  "  '. • •  s p e c i m e n s o f 26 were i n v e s t i g a t e d .  I n the  first  c a s e , shown i n . F i g u r e X V I I , t h e d e n s i t y c a l c u l a t i o n s were n o t made.  As  seen from the c a p i l l a r y  height-temperature  curve", t h i s s p e c i m e n showed marked d e v i a t i o n s from: t h e curves. curves  These c a n be no q u e s t i o n a s t o t h e obtained.  t h r e e t i m e s , ,and  shape o f  S e c t i o n A-B'^Gjof F i g u r e X V I I was i n one  c a s e , p o i n t :A was  a t 4-9.84o.04°G:. on d e s c e n d i n g  usual  the  repeated  h e l d f o r 24  temperature s c a l e .  As  hours  before,  t h e d o t t e d p a r t o f t h e c u r v e marks a r e g i o n o f u n c e r t a i n readings.  A r e g i o n . o f i n s t a b i l i t y was  r i s i n g t e m p e r a t u r e b e t w e e n D and E. dency t o o s c i l l a t e , and  i n some c a s e s  found t o e x i s t  The  on  m e r c u r y had a  two r e a d i n g s a t  tenthe  same t e m p e r a t u r e were w i d e l y d i v e r g e n t f o r c o n s e c u t i v e  A n o t h e r sample was d e n s i t y curve  p u r i f i e d and  investigated.  i s shown i n F i g u r e X V I I I , , and  r e l i a b l e of those  o b t a i n e d by t h e a u t h o r .  t h e r e was  The  observed  the  readings  from the  were  general  same r i s e  second i n t h a t the  The  Again  ( t o a much  a t the t r a n s i t i o n p o i n t .  member o f t h e s e r i e s showed t h i s phenomenon. differed  least  f o r purposes of comparison.  a r e g i o n o f i n s t a b i l i t y and  l e s s e r e x t e n t ) was  The  i t i s the  taken i n a h u r r y , i t b e i n g d e s i r e d t o o b t a i n the shape o f t h e d e n s i t y c u r v e  runs. .  No  first  f o r m e r showed no  sample indica-  t i o n whatsoever of a sudden drop i n c a p i l l a r y h e i g h t a t t r a n s i t i o n p o i n t , w h e r e a s i n t h e s e c o n d c a s e t h e r e wa.s u s u a l .drop, a l t h o u g h  other  the the  t h e m e r c u r y d r o p p e d s e v e r a l cm. b e l o w thee  v a l u e . s h o w n on t h e c u r v e , and t h e n r o s e a g a i n . As g i v e n i n t h e g e n e r a l d i s c u s s i o n on t h e o r y , 26 e - r a y r e s u l t s d i f f e r i n g f r o m any o t h e r o f t h e s e r i e s .  showed In a  p l o t o f s p a c i n g v s number o f c a r b o n a t o m s , g i v e n i n F i g u r e XVI:, values for 26,27 28,29,30,  P i p e r , u s i n g h i s own  and 36',' and t h o s e o f M u l l e r and S a v i l l e  for 20,  31,  32,  34,  35,,  22,  and  24,  shows t h a t 26 h a s t h r e e s p a c i n g s , i n c o n t r a s t t o t h e o t h e r two Thus i t m i g h t be e x p e c t e d t h a t 26 w o u l d  well-marked s e r i e s . differ  f r o m t h e o t h e r members, b u t no e x p l a n a t i o n c a n be  f o r t h e r e a s o n s why  offered  i t s h o u l d show s u c h marked d e v i a t i o n s  t h e a d j a c e n t members.  from  -  so  Figure  XV!  . C e r t a i n l y w i t h the apparatus used the temperature was  control  n o t s u f f i c i e n t l y e x a c t t o o b t a i n a smooth cnvve i n t h e r e -  gion of t r a n s i t i o n .  W i t h d e s c e n d i n g t e m p e r a t u r e , i t was  I m p o s s i b l e t o o b t a i n good r e a d i n g s f r o m 40-56°C. sample i n v e s t i g a t e d , t h i s r e g i o n was  carefully  temperature b e i n g kept w i t h i n t h i s range t h e r e g i o n B3-B3* ( F i g u r e X V I I ) , was f o r 15°G.  The  l i n e was  found  I n the  first.,  checked, the  f o r s e v e r a l weeks,'and,  c h e c k e d e v e r y 0.2°  eqch  found t o correspond i n slope t o  l i n e s f o u n d i n t h e same r e g i o n f o r o t h e r members.  The  way  similar straight.  —61— l i n e o b t a i n e d was  ^ p r o d u c i b l e w i t h i n the degree  o f t h e c a t h a t o m e t e r , and t h e c r y s t a l l i n e stable  one,  f o r m was  of accuracy evidently  a  -63—  FIGURE XV7III  —64— Octacosane; The tion hut  and  o c t a c o s a n e c u r v e was melting point.  i t i s not the  first  The  o n l y one  regular with respect  heavy curve i s the  obtained.  When t h e  i n v e s t i g a t e d , t h e t e m p e r a t u r e was  one  obtained.  On  uniform  divergence  t o o k p l a c e , and  on .the way  back.  and  s i x curves obtained,  of the  f o l l o w e d A-C.,  The  reached.  the  e n t i r e c u r v e was  w i t h i n the  be  mercury would not w o u l d be  fill  From t h e n on  minute v o i d s are  completely.  traced  two  divergence.  It  formed w h i c h  the  I f t h i s were t r u e , t h e n the;c a p i l l a r y - h e i g h t readings  t h e d e n s i t y w o u l d be  e n t i r e c u r v e w o u l d be .'displaced v e r t i c a l l y , constant  a  t r a c e d f o u r t i m e s more,  too  low.  I n t h a t c a s e , h o w e v e r , i t w o u l d seem l i k e l y t h a t  the  heavy  f r o m 0°Gj,  f o u r f o l l o w e d A-B-: and  d r o p f a r enough, t h e  t o o h i g h , and  thee  l i m i t o f measurement.  that i n s o l i d i f y i n g ,  m e r c u r y does n o t  The  same c u r v e was  I t i s d i f f i c u l t t o see what c a u s e d t h i s may  was  r a i s e d t o 8 5 ° G and  t a k i n g t h e t e m p e r a t u r e up  t h e p o i n t s c h e c k e d u n t i l p o i n t A was  transi-  assumed,  sample  c u r v e p l o t t e d on a d e s c e n d i n g t e m p e r a t u r e s c a l e . l i n e was  to  deviation actually  obtained.  the  r a t h e r than w i t h  FIGURE X I X  —66— Nonacosane; . Muller attributes 29:  orthorhombic,  a t l e a s t t h r e e c r y s t a l l i n e forms t o  m o n o c l i n i c , and t r i c l i n i c ,  arrangement i n the t r a n s i t i o n r e g i o n . the lize  As d i s c u s s e d  elsewhere  odd members w i t h 11 o r more c a r b o n atoms n o r m a l l y i n t h e A form, and t h e f i r s t  been p o s t u l a t e d  spacings  2 0  For the t r a n s i t i o n  a c r y s t a l l i n e form h a v i n g  correspond  cross section.  :  normally  T h i s f o r m may  t o M u l l e r ' s t y p e B : w i t h no m o l e c u l a r  From t h e f o r e g o i n g i t m i g h t be e x p e c t e d  region  t h e same 0 0 1  as t h e A f o r m - ( i n w h i c h t h e t r a n s i t i o n form  c r y s t a l l i z e s ) b u t of d i f f e r e n t  crystal-  t r a n s i t i o n i s n o t accompan-  i e d by a change i n t h e 0 0 1 s p a c i n g . has  w i t h a hexagonal  tilt.  t h a t the s o l i d  s e c t i o n f o r 2 9 w o u l d be i n t h e same r e g i o n a s t h e t r a n s i t i o n f o r m s f o r t h e e v e n members. t h a t t h e t r a n s i t i o n ,1s  From t h e c u r v e  f a r l e s s marked t h a n  i t c a n be s e e n f o r the even  members, a n d b y c o m p a r i s o n w i t h 2 8 and 3 0 , ' i n c l u d e d f o r comparison, t h e curve lated.  shows t h e same g e n e r a l  shape a s p o s t u -  T e m p e r a t u r e .in ° C FIGURE XX.  Triacontane; ;  The 0 f o r m i s t h e c r y s t a l l i n e  state  f o r the* e v e n members,  is  only  configuration 1  M u l l e r ^ - mentions  o b s e r v a b l e when t h e c r y s t a l s  fact  of 3 0 .  t h a t a l l o f t h e members i n v e s t i g a t e d by t h e  may be n o t e d t h a t crystallized  pattern  parallel lines  It is  dilatometer  i n the s o l i d s t a t e . I t :  i n t h i s w o r k t h e s a m p l e s must o f n e c e s s i t y  from.the l i q u i d  I n 30 there  solvent,  c a n be i n t e r p r e t e d i n t h e l i g h t ^ o f t h e  method show p r a c t i c a l l y  be  t h a t the C form  a r e o b t a i n e d from a  e x c e p t when t h e members a r e i n t h e n e i g h b o r h o o d h a r d t o see how t h i s  i n the s o l i d  are 2 l i n e s  i n the t r a n s i t i o n  state.  formed  i n the x-ray  regionone  diffusion  close, t o the o r i g i n a l  1 1 0 l i n e s , a n d t h e s e c o n d ;weaker, a b o u t h a l f way b e t w e e n t h e original  110 and 2 0 0 r e f l e c t i o n s .  approaches  60° n e a r t h e m e l t i n g  The a n g l e 0 (o£' p>43)  point,  close packing f o r the l i q u i d range. 3 0 appears t o be e n t i r e l y point, transition upper  ". ?.  regular  as r e g a r d s  s t r u c t u r e may r e s u l t  changes  magnitude.  melting,  or d i f f e r e n c e s i n  f r o m t h e above s p a c i n g  t i o n s h i p s , t h e y do n o t show up i n d e n s i t y rable  hexagonal  temperature and r a n g e , and lower s o l i d and  l i q u i d r a n g e s , so w h a t e v e r  crystalline  indicating  rela-  v a r i a t i o n s o f measu-  —70—  Dotriacontane t .:  s a m p l e s o f 32 were i n v e s t i g a t e d .  Three separate  curves obtained  are very 26,  e n t i r e range.  28,  c l o s e t o one  30,  32 and  34  another throughout  from the  others  i n t h a t the  three the  show good c o r r e l a t i o n i n  the r e l a t i o n s h i p between d e n s i t y c u r v e s . ent  The  32  i s somewhat  change f r o m one  differ-  state to  another  through the t r a n s i t i o n r e g i o n f o l l o w s a p e r f e c t l y r e g u l a r and  does n o t  show t h e  same l i n e o f c o n s t a n t  slope  curve  ( indicating  a s t a b l e c r y s t a l l i n e form i n the t r a n s i t i o n r e g i o n )  as do  the  others. I t was  wondered whether or hot the d e n s i t y c u r v e s c o u l d  u t i l i z e d as a means o f i n d i c a t i n g t h e p u r i t y o f t h e The  most o b v i o u s c h e c k w o u l d be  shown by  Piper  2 2  , two  specimen.  the m e l t i n g p o i n t , but  as  hydrocarbons of unequal l e n g t h c o u l d  c o m b i n e d i n s u c h a p r o p o r t i o n as t o g i v e t h e  be  same m e l t i n g  be point,  as a homologue l y i n g b e t w e e n them. According  to P i p e r  point i s p a r t i c u l a r l y be  2 2  and  0  K o l v o o r t , the  s e n s i t i v e t o i m p u r i t y , and  t a k e n as a c r i t e r i o n o f p u r i t y .  importance, at p r e s e n t , are not  This  h o w e v e r , as t h e  one  therefore  might  practical  lower t r a n s i t i o n  points  reliability..  s p e c i m e n i n v e s t i g a t e d w h i c h showed a marked d e p r e -  s s i o n o f m e l t i n g p o i n t was and X X I I t h a t t h e i n t h a t the  transition  i s of l i t t l e  known w i t h a s u f f i c i e n t d e g r e e o f  The  lower  16  and  32  change f r o m t h e  16.  I t may  be  seen from F i g u r e s  c u r v e s h a v e one s o l i d t o the  property  X.  i n common  l i q u i d form f o r 16,  and  — T i t h e change front l i q u i d t o t r a n s i t i o n forms i n 3 2 , curved s e c t i o n .  The r e a s o n i n e a c h c a s e may  mamely,.the p r e s e n c e o f i m p u r i t y . light i t may  show a b r o a d  be t h e same;  On t h e o t h e r h a n d , i n t h e  o f t h e f a c t t h a t 3 s i m i l a r c u r v e s were o b t a i n e d f o r 3 0 , be t h a t 32 shows t h i s i r r e g u l a r i t y b e c a u s e  molecular forces peculiar to i t s chain length.  The  f r o m l i q u i d t o s o l i d s t a t e w i t h o u t t r a n s i t i o n was s h a r p i n t h e c a s e o f t h e p u r e sample  of 16;  of  interchange  extremely  on t h e b a s i s  of  t h i s e v i d e n c e i t w o u l d a p p e a r as t h o u g h some c o n s t a n t i m p u r i t y were p r e s e n t i n a l l  t h r e e samples  o f 32  examined  Tetratrlacontane; 34,  t h e d e n s i t y c u r v e f o r w h i c h i s shown i n F i g u r e X X I I I ,  appeared normal i n every r e s p e c t .  —72 —  FIGURE "XXI I .  T e m p e r a t u r e i n °C FIGURE X X I I I  CORRELATION OP RESULTS Transition Points: The t e m p e r a t u r e o f t h e s e c o n d t r a n s i t i o n , p o i n t upon c o o l i n g ) i s g i v e n  i n T a b l e XX;  (obtained  Included w i t h these  f o r 44.  i m e n t a l l y determined temperatures i s the single value According shable  1  t o M u l l e r ^ , . the' t r a n s i t i o n  f r o m t h e m e l t i n g p o i n t f o r 44.  indistingui  A s s u m i n g t h i s t o be  Transition  16  p o i n t becomes  exper-  true  Point  None  18" 32  20 22 24. 26 28  40 47.9  48.8 54.0 57.1 60,0 63.5 68.4 84.8  29  3032  34. 44  T a b l e XX. and  u s i n g o u r s e l e c t e d v a l u e s f o r t h e m e l t i n g p o i n t o f 44,, (cf.  p..  ) i t s value  i s t a k e n a s t h e t r a n s i t i o n p o i n t o f 44.  values  are p l o t t e d i n F i g u r e XXIV.  values  of the second t r a n s i t i o n  From t h e c u r v e  These  obtained,  p o i n t h a v e b e e n s e l e c t e d and  I n T a b l e X X I t h e y a r e compared w i t h t r a n s i t i o n  temperatures  g i v e n by P i p e r . 24  shows t h e g r e a t e s t d e v i a t i o n f r o m a smooth c u r v e .  t h e d i s c u s s i o n on 24  ( c f . p.55...) i t was p o i n t e d  out t h a t  member showed marked d i f f e r e n c e s i n s e v e r a l r e s p e c t s .  In  this  —76—  00  Transition Temperatures p l o t t e d against Number of Carbon Atoms f o r the n - s t r a i g h t chain a l i p h a t i c s ,  90  80  18  20  22  24  26  28  30  3 2 34 36 38 40 42 Number o f Carbon Atoms,  FIGURE  XXIV  44  46  48  50  It  i s n o t p o s s i b l e t o give a c l o s e comparison  s e l e c t e d v a l u e s and those o f P i p e r .  of the  The t r a n s i t i o n - , p o i n t s  o b t a i n e d from t h e t e m p e r a t u r e - d e n s i t y curves a r e o b t a i n e d i n e x a c t l y t h e same manner a s t h e s e t t i n g p o i n t , a n d t h e y c a n be m e a s u r e d w i t h any d e g r e e o f f i n e n e s s d e s i r e d  (cf. pvie),  w h e r e a s P i p e r . r e c o r d s two s e t s o f v a l u e s , one r e s u l t i n g  from  a d e s c e n d i n g , t h e o t h e r from an a s c e n d i n g temperature, and furthermore, they are given i n a range. Selected Trans p t .  n.  20  21 22 24 25 26 27  28  38  39 40 41 42 43 44 45  Diff.  32.0°C:  -1.2°C  40.0  -0.0  47.9:  .2.9  48.8"  -0.4  54.0 57.1 60.0  -1.2 -0.4 0.0  63.5  -1.0  68.4  -0.2  36.3:  23  33 34 35 36 37  Observed Trans p t .  26.0 29.7 33.2  18 19  29 30 31 32  Piper's Values ' f o r Trans P o i n t Cooling. Heating.  .  40.0 42 ..2 45.0 47.8 50.2. 52.9 55.2 57.5 60.0 62.3 64.5 66.8 68.6. 70.4 72.8 74.2 76.0 77.6 79.1 80.8 82.0 83.4 84.8  48.3 51.0 54 55-8 58.0 61.8 63.9 68.5 70.5 ••7.2.5  51.5-52.0 52.8-53-0 57.0-57.5 57.3-57.5 59.0-59.5..:, 62.0-62.5 65.2-65.4  ., .-'  69.2-69.4 71.8-72.0 73.9-74.1  T a b l e XXIT  —78—  The  t r a n s i t i o n p o i n t can approach the m e l t i n g p o i n t i n  e i t h e r one  o r b o t h o f two ways.  The  temperatures can  converge,  or t h e d e n s i t y , o f t h e t r a n s i t i o n s t a t e ' c a n a p p r o a c h  t h a t of the  solid  of the  state.  I n Table XXII i s r e c o r d e d the d e n s i t y  hydrocarbons  i n v e s t i g a t e d a t the t r a n s i t i o n p o i n t , t o g e t h e r w i t h  the  t r a n s i t i o n temperature, the s e t t i n g p o i n t temperature,  the  d i f f e r e n c e b e t w e e n them.  In Figure too  XXV  i s shown a p l o t of. t. v s n.  The  points  d o e s seem a t e n d e n c y  temperature  f o r d i f f e r e n c e between the  and m e l t i n g p o i n t t o a p p r o a c h  ( c f . p.39 ) approach  e a c h . o t h e r a t 44, t h e n ( f r o m F i g u r e XXV0, t h e d e n s i t y the  solid  s t a t e s h o u l d be a p p r o x i m a t e l y O . 8 9 8 .  shown a n e x t r a p o l a t i o n o f s o l i d  slightly  above t h a t  y\  In Figure  c u r v e f o r 44 w i l l  o f 34) down t o t h e m e l t i n g p o i n t  d e n s i t y o f 44 a c c o r d i n g  an  be o f 44.  t o t h i s e x t r a p o l a t i o n w o u l d be 0.917/  compared t o t h e O . 8 9 8 f r o m F i g u r e  From F i g u r e X  o f 44 i n  f o r m d e n s i t i e s ( b a s e d on  a s s u m p t i o n t h a t the s o l i d phase d e n s i t y only  trantision  0 a t n = 44.  I f t h e d e n s i t i e s o f t h e A and C forms  The  are  s c a t t e r e d t o w a r r a n t d r a w i n g a c u r v e t h r o u g h them, a l t h o u g h  there  is  and  XXVI.  i t - would appear  t h a t the l a t t e r  l o w , and t h a t t h e p r e d o m i n a t i n g e f f e c t w i t h length i s a d i m i n i s h i n g - t r a n s i t i o n range.  f i g u r e i s too  increasing  chain  n  Density a t . t .p.  Temp. o f t .p.  20  0.8670  32.0  22  0.8690  40.0  44.1  4.1  24  0.8673  47.9  50.7 ,  2.6  26  0.8722  48.8  55.8  7.0  .28  0.8788  54.0.  61.2  7.2  -30  0.8802  60.0  65.4  5.4  32  0.8782  63.5  69.5  6.0  34  0.8836  68.4  72.9  4.5  29  57.1*  63.3  6.2  31  6-1.8*  68.0  6.2  35  70.5^  74.4  3.9  m.p.  t.  36.2  4.2  18^  .  * Values t a k e n from  ;  Piper.  Table  XXII  P l o t of _ Number of Carbon Atoms vs Density at the T r a n s i t i o n Point f o r the.Normal S t r a i g h t - C h a i n A l i p h a t i c Hydrocarbons•  \ o  \  \  P l o t of Number of Carbon Atoms? vs -Temperature D i f f e r e n c e between^ M e l t i n g Point a n d • T r a n s i t i o n P o i n t i f o r the Normal S t r a i g h t Chain o A l i p h a t i c Hydrocarbons • 1  \  \ \ \  \ \ \ \  \ o  \  18  20  22  24  26  28  30  32  34'.  FIGURE  36^  38  40  42  44  46  48  The  q u e s t i o n a r i s e s a s t o t h e shape o f t h e d e n s i t y c u r v e s  over t h e e n t i r e temperature  range  f r o m 0-500°Abs, t h a t i s f r o m  a b s o l u t e z e r o t o w e l l above t h e b o i l i n g p o i n t . e f f i c i e n t of expansion of a c r y s t a l l i n e at  s u b s t a n c e becomes z e r o  0°Abs,.it i s p r o b a b l e t h a t t h e d e n s i t y a p p r o a c h e s  v a l u e c l o s e t o 1.0 a t v e r y l o w t e m p e r a t u r e s . of  Since the co-  some  The d e n s i t i e s  t h e l o n g - c h a i n members have n o t b e e n m e a s u r e d a t h i g h e r  t e m p e r a t u r e s , b u t i t was t h o u g h t p o s s i b l e t o o b t a i n some knowledge o f these r e g i o n s from d a t a a l r e a d y o b t a i n e d f o r the l o w e r members.  I f we assume t h a t t h e l i q u i d l i n e s  f o r a l l hydrocarbons  a r e p a r a l l e l a n d o f t h e same g e n e r a l shape t h r o u g h o u t , t h e n t h e s l o p e 'of a l l members a t any g i v e n t e m p e r a t u r e  interval  between  b o i l i n g - p o i n t a n d m e l t i n g - p o i n t ( s a y , h a l f - w a y between')' s h o u l d be  a p p r o x i m a t e l y t h e same.  t a k e n from  The ing  The d a t a , g i v e n i n T a b l e X X I I T i s  Deanesley.  temperature  i n t e r v a l b e t w e e n b o i l i n g poSlnt a n d f r e e z -  p o i n t f o r 26 i s 3 6 6 . 4 - 5 5 , o r 3 1 1 ° G V In Figure XXVII, t h i s  interval  i s divided into  fractions,  and v a l u e s o f the c o e f f i c i e n t  fractional  distances within this  interval  decimal  of expansion a t ( t a k e n from t h e l a s t  c o l u m n o f T a b l e 'XXIII a r e p l o t t e d . b o i l i n g p o i n t we know, ( i t i s e s s e n t i a l l y 2  know t h a t d ( d ) / d t  2  infinity.)  We  i s 0 f o r t h e 15-20°Gj. r a n g e .above t h e  also  n  d(d)/dt  t u p . , at;. 760 mm. 76b mm.. 36.1 2> 0.000975 -129.7 6 0.0008917 68.7 ' - 95.3 98.4 - 90.6 7 0.0008407 8 0.000803 ; 1 2 5 . 6 - 56.8 9 0.000774 1 5 0 . 7 : - 53.7. 10 0.000751 1 7 4 . 0 - 29.7: 11 0.000733 195.8 - 25.6: 12 0.000719 216.2 - 9.60 0.000708 2 3 5 . 5 6.00 13 14 0.000699 253.65 5.5 0.000692 270.6 ' 10.0 15 16 0 . 0 0 0 6 8 6 2 8 6 . 5 18.1 :  ts , bp to fp 165.8 • > 164.0 189.0' 182.4 204.4 203.7; 221.4 225.8 241.5 248.1 260.6 268.4 5  :  t,20° F r a c t i o n o f 20°CJ t o mp. b e t h . bp a n d f p . 0.962 149.7 0.704 115.3 110.6 0.584 0.421 76.8 O.360 73.7 0.244 49.7 45.6 0.2062 29.6 0.131 26 .0 0.108 0.058 14.5 10. 0.042 2'. 0 ..007  .T&ble X X I I I I  m e l t i n g p o i n t (deduced from t h e l i n e o b t a i n e d i n t h e case  o f c o n s t a n t d e n s i t y change  o f each hydrocarbon  investigated.)  Table  X X I V g i v e s t h e v a l u e s o f d ( d ) / d t . i m m e d i a t e l y above t h e m e l t i n g p o i n t f o r t h e e v e n members. n.  d(d)/dt  18 20 24 26 28 30 32 34  O.P00634 O.OOO632 0.000622 O.OOO668 0.000628 .0.000641 0.000620  Average:  O.O0O636 Table  Therefore  t h e curve  XIF7.  i n F i g u r e X X V I I s h o u l d be a s y m p t o t i c ,  t o d ( d ) / d t = O.OOO636 a t t h e l o w e r b o u n d a r y l i m i t . lower l i m i t i n g v a l u e o f d ( d ) / d t from t h e curve 0.00069.  A c t u a l l y the  i s O.OOO68 t o  I t i s n o t p l a i n why t h e c a l c u l a t e d v a l u e o f d(d)/dt'.  a t t h e m e l t i n g p o i n t s h o u l d be so much h i g h e r  than the observed  value. Despite  the u n s a t i s f a c t o r y q u a n t i t a t i v e r e l a t i o n s h i p  shown i n F i g u r e X X V I I , h o w e v e r , i t does i n d i c a t e t h a t t h e r e i s probably  no marked i n c r e a s e  I n the slope  of the d e n s i t y  curve  as t h e t e m p e r a t u r e a p p r o a c h e s t h e b o i l i n g p o i n t , a n d t h a t t h e sharp decrease i n d e n s i t y a t the b o i l i n g point takes w i t h i n a s m a l l r a n g e , say l e s s t h a n  5°®..  place  —85  —  SUMMARY.. 1.  M e l t i n g .Point v a l u e s  f o r the e n t i r e n - p a r a f f i n hydrocarbons  have b e e n compared and a t a b l e o f t e n t a t i v e v a l u e s 2.  Density  c u r v e s f o r 16,20,22,26, a n d 34 have b e e n  3.  The above c u r v e s ,  together  32 have b e e n d i s c u s s e d i n the l i q u i d , 4.  arranged. obtained.  with those f o r 24,28,29,30,  i n terms of c r y s t a l l i n e  t r a n s i t i o n and s o l i d  and  structure  states.  T r a n s i t i o n p o i n t s o f a l l members f r o m 16 t o 44 o f t h e e v e n s e r i e s h a v e b e e n c o r r e l a t e d , and t h e a p p r o a c h  of m e l t i n g  p o i n t and t r a n s i t i o n p o i n t w i t h i n c r e a s i n g c h a i n  length  discussed. 5.  An a t t e m p t h a s been made t o p r e d i c t t h e shape o f t h e d e n s i t y t e m p e r a t u r e c u r v e s f o r t h e e v e n n - p a r a f f i n h y d r o c a r b o n s of. long carbon chain  over the e n t i r e temperature  range.  BIBLIOGRAPHY I . . A u s t e n . J . Am, Chen. S o c . 5 2 , , 1 0 4 9 , 1930. ( G i v e s r e l a t i o n b e t w e e n m e l t i n g p o i n t s a n d number o f c a r b o n atoms f o r a l l homologous s e r i e s . ) 2  '  3,  B u c k l e r a n d G r a v e s . I n d . E n g . Chem., 19, 7 1 8 , 1927. |A s t u d y o f h y d r o c a r b o n s i n v a r i o u s k i n d s o f waxes.) Garothers.  Hill.  5 2 7 9 , , . 1930.  K l r b y . Jacobson.. J . Am. Chem. .Soc., 5 2 . .  (Gives melting p o i n t s f o r 40,50,60,70, a l s o  synthesis.)  4-'  Go 1 1 i n s . J . S o c . Chem. End.-, 5 4 , 3 3 , 1 9 3 5 . (The a c i d s : o f C h i n e s e a n d E s p a r t o G r a s s Waxes a n d t h e H y d r o c a r b o n s o f E s p a r t o a n d ande 1 i l i a . Waxes ..)'..  5>  D e a n e s l e y a n d Gar l e t on. J . ' P h y . Chem. 4 5 , 1 1 0 4 , 1941.. ( P h y s i c a l Constants o f Hydrocarbons.)  6..  G a r n e r . Van B i b b e r , and K i n g . J . Chem. S o c . 1 5 3 3 , , 1931.. (The M e l t i n g P o i n t s a n d H e a t s o f C r y s t a l l i z a t i o n o f t h e Normal Long-Chain HydrocBbons,)  7.  G a s c a r d . A n n . Chem, 1 9 2 1 , 1 5 , 3 3 2 . . ( G i v e s m e l t i n g p o i n t s ' o f 36^ 5 4 , 6 2 , a n d 64.)  8.  H i l d e b r a n d a n d W a c h t e r . J . Am Chem. Soc.,, 5 1 , 2 4 8 7 , 1929. (The M e l t i n g P o i n t s o f N o r m a l P a r e f f f i n s . )  9.  K o l v o o r t . J o u r n . I n s t . P e t . Tech.,, 24„ 3 3 8 , 1938. "["Crystal T w i n s o f N o r m a l 24 a n d t h e I n f l u e n c e o f P h a s e T r a n s i t i o n s on T h e i r O r i e n t a t i o n . )  10. M o r r i s . M a s t e r ' s T h e s i s . U n i v e r s i t y of B r i t i s h Columbia. ( M e l t i n g p o i n t and d e n s i t i e s f o r 3 2 . ) 1 9 3 8 . II.  M o i l l l n . . P r o c . Camb. P h i l . S o c , 3 4 , 4 5 9 , 1 9 3 8 . Ja n o t e on t h e M e l t i n g P o i n t s o f P a r a f f i n s a n d F a t t y  Acids.)  1 2 . M u l l e r . . P r o c . R o y . S o c . ( L o n d ) A 1 2 0 , 4 3 7 , -1028.. I f e a s u r e m e n t on a s i n g l e c r y s t a l o f 2 9 ( x - r a y . ) ) ,13. - M u l l e r . P r o c . R o y . S o c . ( L o n d ) A 1 2 4 , 3 1 7 , 1 9 2 9 . ( E x p l a i n s why o d d a n d e v e n members behave d i f f e r e n t l y . ) 14. M u l l e r . . P r o c . R o y . S o c . ( L o n d . ) A 1 2 7 , . 3 0 , 1 9 3 0 . (The C r y s t a l S t r u c t u r e o f t h e N o r m a l P a r a f f i n s a t . T e m p e r a t u r e s Ranging from t h a t of L i q u i d A i r t o t h e M e l t i n g P o i n t s )  __87—  •: BIBLIOGRAPHY .(Continued) 15.  M u l l e r . P r o c . Roy. S b c . ( L o n d ) A 1 5 4 , 624, 1 9 3 1 . (The V a n d e r W a l l s P o t e n t i a l and t h e L a t t i c e E n e r g y o f a NormaL-CH C h a i n M o l e c u l a r I n a P a r a f f i n C r y s t a l . ) 2  16.  M u l l e r . P r o c . R o y . S o c . (Lond) 514, 1932. (An x - r a y I n v e s t i g a t i o n o f t h e N o r m a l P a r a f f i n s Near Their Melting Points.)  17.  Oldham, a n d . U b b e l o h d e • J . Chem. S b c . 2 0 0 , - 1 9 3 8 . . (A M o d i f i e d G r i g n a r d R e a c t i o n i n t h e S y n t h e s i s o f H y d r o c a r b o n s .)  18.  P a r k s a n d H u f f m a n n . J . Am. Chem. S o c . 5 2 , 1 0 3 0 , 1 9 3 0 . • TGives H e a t s o f C r y s t a l l i z a t i o n o f 5 , 6 , 7 * 8 , a n d 2 0 a n d m e l t i n g p o i n t s o f t h e s e members.)  19  P a r k s a n d T o d d . I n d . E n g . Chem. 2 1 , 1236,.. 1 9 2 9 . ( H e a t s o f F u s i o n o f Some P a r a f f i n H y d r o c a r b o n s . )  20.  P a t t e r s o n , M a s t e r s T h e s i s ; U n i v e r s i t y o f B r i t i s h Columbia 1940, ,(Preparation (The D e n s i t i e s a n d T r a n s i t i o n P o i n t s o f C e r t a i n L o n g Chain P a r a f f i n Hydrocarbons.)  21.  Peterson. Z e i t . Electrochemis. 1 2 , 141, 1936. ( P r e p a r a t i o n s o f Normal S t r a i g h t - c h a i n h y d r o c a r b o n s by Electrolysis.)  22.  P i p e r . e t . a l . ...Bio. J . 2 5 , 2 0 7 2 , . 1 9 3 1 . ( S y n t h e s i s and C r y s t a l l i n e S p a c i n g s o f C e r t a i n Long C h a i n P a r a f f i n s , Ketones, and Secondary A l c o h o l s . )  23.  S a v i l l e . . Chem S o c . 1 2 7 , 5 9 1 , . 1 9 2 5 . (Arrangement o f A l i p h a t i c Chains.)  8  ;  . ...  24.  S e v e r . J . Am. Chem. S o c . 6 0 , 8 2 7 , 1 9 3 8 . ( F r e e z i n g P o i n t C u r v e s o f 32 i n 1 2 , 1 0 , 8 , 6 , C y c l o h e x a n e and Benzene.)  25.  S e y e r a n d F o r d y c e . J o u r n . Am. Chem. S o c . 5 8 , 2 9 2 9 , 1 9 3 6 . ( F r e e z i n g P o t a t / C u r v e o f 32 i n Propane and Butane.)  26.  S h e p a r d , Henne„ a n d M i d g e l e y .  J . Am Chem. S o c . 5 8 , 1 9 4 8 ,  1931.  ( P h y s i c a l P r o p e r t i e s of the n o r m a l - P a r a f f i n Hydrocarbons, P e n t a n e t o Dodecane.). 27.  S t e w a r t . Chem. R e v i e w s , 6 , 4 8 3 , 1 9 2 9 . X l o l e c u l a r S t r u c t u r e a s I n t e r p r e t e d by x-Ray Measurements i n L i q u i d s . )  diffraction  —88—  28.  S t e w a r t jand Morrow. .  .  P h y s i c a l Reviews, 2 9 / 9 1 9 , 30,  232,  1927.  1927..  ( M o l e c u l a r Arrangement C a l l e d C y h o t a x i s , g i v i n g x - r a y d i f f r a c t i o n patterns.) .* , P h y s i c a l R e v i e w s , 3 1 , 2, 1928. . 32,  558,  ( D e t a i l e d account of x-ray d i f f r a c t i o n p a t t e r n s •conclusions.)  1928.  and  2299  Stoll-Gbmpte. R u z i k a . H e l v . Actfea. 9 , 4 9 9 , , 1 9 2 6 . . t I n c l u d e s d e n s i t y c u r v e r e l a t i o n s h i p f o r n o r m a l aliphatics«,)  30.  St o i l and S t o l l - C o m p t e . Helv.. Chim. A c t a . TStudy o f H y d r o c a r b o n R i n g s . )  31.  13,  II85,  1930  Tsakolotos. Compt R e n d . .143, 1 2 3 5 , 1900. (On t h e M e l t i n g P o i n t s o f H y d r o c a r b o n s Homologous w i t h ' .' Methane.) i  32.  Yatabe.  Master's Thesis.  U n i v e r s i t y of B r i t i s h  Columbia,,  1939.  (The 33. .  D e n s i t y and T r a n s i t i o n P o i n t s o f n-24.)  K r a f f t , Ber, 19, 2219, 1886.. (.Synthesis o f - H y d r o c a r b o n s . )  34.  H e l l and H a g e l l e .  35•  Hydrocarbon  36..  International Critical  37.  Sorabji. J . Chem. Soc. 47, 39,. 1885. X M o d i f i c a t i o n of K r a f f t S y n t h e s i s of Hydrocarbons.) •  1  Ber..  Constants.. Tables.  '  APPENDIX I  PREPARATION AND PURIFICATION OF  THE  HYDROCARBONS  :;  T e t r a d e c a n e V Pentadecane, a n d Hexaclecane: : These t h r e e members were o b t a i n e d  from Parks o f the  U n i v e r s i t y o f S t a n f o r d , a n d were p a r t o f t h e same m a t e r i a l s 14 a n d 15 were  u s e d i n h e a t o f f u s i o n measurements. considered  t o be o f s u f f i c i e n t p u r i t y t o be e m p l o y e d a s  received The sample o f 1 6 was f o u n d t o h a v e a s e t t i n g p o i n t o f 15.9°G, a t l e a s t 2.0°C below t h e accepted and  i t was deemed n e c e s s a r y  ation.  A.5-gram  t o repeat  sample was o b t a i n e d  value  ( c f page 3 8 ) ,  the d e n s i t y  determin-  through the courtesy  o f t h e S h e l l D e v e l o p m e n t Company, a n d was p a r t o f a specimen u s e d by Deanesly and C a r r o t h e r s ^ p o i n t , and r e f r a c t i v e considered order  index measurements.  This  melting-  sample was  t o be o f t h e h i g h e s t p o s s i b l e p u r i t y , . a n d i n  t o a v o i d any ' c o n t a m i n a t i o n , .was t r a n s f e r r e d t o a  d i l a t o m e t e r bulb w i t h as l i t t l e and w i t h o u t  further  exposure t o a i r a s p o s s i b l e ,  treatment.  Octadecane:  .  18 was s y n t h e s i z e d b y t h e P e t e r s o n 89-90)  i n density,  f r o m Kodak C a p r i c a c i d .  a c e t i c acid-hydrocarbon  ( c f page  A c e t i c a c i d was u s e d as a  solvent,', the c r y s t a l l i z e d n e e d l e s b e i n g temperature, just s l i g h t l y  synthesis  filtered off at a  above t h e f r e e z i n g p o i n t o f t h e  solution.  --90--  APPENDIX I Eicosane: 20 was  (Continued)  s y n t h e s i z e d from D e c y l  same method as t h a t u s e d f o r 2 4 ,  a l c o h o l (Kodak) by  28,  and  f r o m s u l p h u r i c a c i d , a c e t i c a c i d , and the  care taken  i n t h e s y n t h e s i s and  was  considered  t o be  one  32,  then  purified  ethyl alcohol.  and  the  of t h e p u r e s t  f o l l o w i n g equations  24,  28,  1,  C H ^ 0 H 4. HI  2.  ••2QiG>H-^i'  are  to  i t  members, u s e d .  The general  a p p l i c a b l e i n form  to  32.  and  ——*  2  1 0  Due  p u r i f i c a t i o n of 2 0 ,  S o r a b j i - ^ m o d i f i c a t i o n of the K r a f f t - ^ r e a c t i o n i s a one,  the  2Na  C  1 0  —»  H2 I 3  2NaI  -t- HgO ". CgoH^  '  -  Docosane: 22 was  s y n t h e s i z e d f r o m L a u r i e a c i d (Kodak) by  electrolysis.  The  method o f p r e p a r a t i o n , ' t a k e n  from P e t e r s o n  N e u t r a l i z e 15 g. ! a u r i c a c i d by w a r m i n g w i t h  approximately  2 1  i s as f o l l o w s : a.  5g. b.  Add  2  together 5g.  c.  of K C 0 ^ p l u s 75cc  Place has  with 50cc  of w a t e r .  o f 96%  e t h y l a l c o h o l and  another  of l a u r i c a c i d . s o l u t i o n i n a 3 0 0 c c b e a k e r , and when t h e d r o p p e d t o 45°C, p a s s a c u r r e n t o f 0.84  between 2 p l a t i n u m  electrodes  temperature amps  ( I f the e l e c t r o d e s  smooth, t h e  surface  a r e a s h o u l d be  h o l d i n g the  t e m p e r a t u r e b e t w e e n 45  approximately and  50°C.  CD. are 15cm?),  —91—  APPENDIX I d.  (Continued)  E v e r y two h o u r s a d d 6 g . o f l a u r i c a c i d d i s s o l v e d I n a l c o h o l u n t i l 40g. o f l a u r i c  a c i d have been a d d e d ,  the e l e c t r o l y s i s p r o c e e d i n g f o r f i f t e e n hours.  The  hydrocarbon  liquid  and  c o l l e c t s on t h e s u r f a c e a s a n o i l y  c a n be removed a s a s o l i d upon c o o l i n g t o room  temperature. e.  Reflux;with a solution  of potassium carbonate or h y d r o x i d e  i n o r d e r t o remove t h e decomposed f.  B o i l w i t h water, a l t e r n a t e l y  g.  any C / q H ^ C O Q C ^ H ^  The c h i e f r e a c t i o n s .1.  .  and b o i l i n g u n t i l a  solution i s obtained.  R e f l u x w i t h a l c o h o l i c potash ly  acid.  cooling, pouring o f fthe  water, and adding f r e s h water clear  lauric  .•2G H 4000H 2  11  i n t h e P e t e r s o n synthesis a r e :  • >:  2C H CpO 1 1  2 . C H C 0 0 -t-H 0  3..  20^2^000  4.  2C  5.  .'CiiHgjCOOH + C H C H 0 H  1 1  25  H  2 5  complete  formed.  2.  11  i n order t o saponify  +  2 3  > 2'C H G00H  2  1:L  23  H  2  +0  H  »- ° 2 2 4 6 •+ 2 C 0  C00  C  5  H  il 23  2  C  0  0  C  >  2  H  ll 23 C-^H^COOC^  These r e a c t i o n s a r e q u i t e g e n e r a l , a n d any o f t h e r a d i c a l used  i n o b t a i n i n g o t h e r members o f t h e s e r i e s c o u l d  be s u b s t i t u t e d f o r t h e C - ^ H ^  group.  APPENDIX I  (Continued)  Docosane; (Continued) R e a c t i o n 3 i s t h e o n l y one d e s i r e d . R e a c t i o n 4 i s s u p p r e s s e d by t h e a d d i t i o n o f p o t a s s i u m carbonate. P e t e r s o n decided from t h e h i g h s a p o n i f i c value o f h i s p r o d u c t t h a t a p p r o x i m a t e l y 4.4% o f C^Hg-jCOOC^Hg,^ and a p p r o x i m a t e l y 2.9%, during the e l e c t r o l y s i s .  of  C^Hg^QOOCgH^.  were  formed  They a r e removed by p r o c e d u r e ' f '  above. That: r e a c t i o n , o f e q u a t i o n ( 2 ) t a k e s p l a c e t o some e x t e n t was d e d u c e d f r o m t h e h i g h e The p e r c e n t y i e l d The p a r t i c u l a r  current  consumption.  i s f r o m 85 t o 9 0 .  sample o f 20 u s e d was n o t t r e a t e d  with  s u l p h u r i c a c i d , a f a c t w h i c h may a c c o u n t f o r t h e somewhat low m e l t i n g p o i n t  ( c f page .21.)  ....  Tetracosane: 24 was s y n t h e s i z e d f r o m E a s t m a n Kodak Company L a u r y l a l c o h o l , u s i n g t h e K r a f f t method ( c f page 90).' Of a l l t h e h y d r o c a r b o n members i n v e s t i g a t e d , 24 gave t h e most marked d e v i a t i o n s from homologous p r o p e r t i e s , and f o r t h i s  reason  ' may be c o n s i d e r e d t o be t h e most s u s p e c t a s r e g a r d s p u r i t y .  —93 — APPENDIX I  .  (Continued)  Hexacosane: 26 was . p r e p a r e d i n t h e s same manner as 2 2 , myristic acid 15g.  (Eastmann Kodak) u n d e r  using  the f o l l o w i n g  conditions  m y r i s t i c a c i d p l u s 4|- g. p o t a s s i u m c a r b o n a t e t o g e t h e r  w i t h 7 5 c c w a t e r p l u s 5 0 c c 9Q% d e n s i t y of 0.96  alcohol, using a current  amps a t a t e m p e r a t u r e  o f 55-60°C.  The  per  85-90  c e n t y i e l d was  Octacosane: 28 was  o b t a i n e d from m y r i s t i c a c i d  ( K o d a k ) , by means  of the F i t t i g R e a c t i o n : -j  a. - 2 5 g .  o f m y r i s t i c a c i d i s m e l t e d and h y d r o g e n  iodide i s -  b u b b l e d i n , t h e HI b e i n g g e n e r a t e d by t h e a c t i o n water  ( 1 p a r t ) and I  2  (11 p a r t s ) .  c o n s i d e r e d c o m p l e t e when a l l r e a c t i o n f l a s k remains Tetradecyl iodide b.  The  The  of  reaction i s  the m a t e r i a l i n the  l i q u i d / a t room t e m p e r a t u r e .  i s formed.  product i s slowly poured  i n t o 200cc  of dry e t h e r  c o n t a i n i n g a s l i g h t e x c e s s o f t h e t h e o r e t i c a l amount o f Ns r e q u i r e d f o r t h e  mixture Is r e f l u x e d  reaction.  c.  The  d.  The-ether i s e v a p o r a t e d o f f a n d t h e e x c e s s Na r e m o v e d w i t h 95%  ethyl  for s i x hours.  alcohol.  -_94--  APPENDIX I ( C o n t i n u e d ) Octacosane: e.  (Continued)  The a l c o h o l  i s e v a p o r a t e d o f f and t h e hydrocarbon  i s p u r i f i e d by t r e a t m e n t w i t h s u l p h u r i c acetic  formed  a c i d and  acid.  NOnacosane: The Bureau ation  sample o f 29 u s e d was o b t a i n e d f r o m t h e A m e r i c a n  of Standards.  I t was p u r i f i e d by r e p e a t e d c r y s t a l l i z  from g l a c i a l a c e t i c a c i d and pure  ether.  Triacontane or d i c e t y l : ' 30 was o b t a i n e d by e l e c t r o l y t i c s y n t h e s i s , u s i n g a s original.charge lOOcc  2 0 g. o f p a l m i t i c a c i d  ( K o d a k ) , 5 g. o f KOH,  o f w a t e r , and 7 5 c c o f e t h y l a l c o h o l , m a i n t a i n i n g a  c u r r e n t d e n s i t y o f 2 . 5 amps/square d e c i m e t e r a t 5 v o l t s , a t a t e m p e r a t u r e o f 70°C. . 3 g - o f p a l m i t i c a c i d ,  dissolved  i n h o t a l c o h o l , were added e v e r y two h o u r s , a n d t h e p r o d u c t was p u r i f i e d b y t r e a t m e n t w i t h c o n c e n t r a t e d s i k l p h u r i c a c i d and  c r y s t a l l i z a t i o n from g l a c i a l a c e t i c  acid.  Dotraicontahe: 32.was s y n t h e s i z e d from C e t y l a l c o h o l same method a s t h a t f H P f i u s e d f o r 2 0 . the  u s u a l manner.  ( K o d a k ) , by t h e  I t was p u r i f i e d i n  I n t h i s case 3 d e n s i t y - t e m p e r a t u r e 1  0  c u r v e s were o b t a i n e d - - ,  two f r o m s y n t h e s i z e d samples a n d  one f r o m a sample o f t h e h y d r o c a r b o n o b t a i n e d f r o m t h e E a s t m a n Kodak Company.  —95  APPENDIX I  —  (Continued)  Tetratriacontane: The 34. )  Peterson  e l e c t r o l y t i c method was  U s i n g Kodak s t e a r i c a c i d , an r e c o v e r y  o b t a i n e d w i t h a c u r r e n t d e n s i t y o f O.98 of  sample o b t a i n e d  obtained  Ubbelohde  by  of 75-80%  was  at a temperature  t h i s method was  in a colorless state.  reason l i e s  circulation  found  t  "Owing t o t h e a p p r e c i a b l e  of a i r o v e r t h e  impossible  I t i s possible that  I n t h e f o l l o w i n g s t a t e m e n t of Oldham  l i q u i d p a r a f f i n s a t 130°G, i t was  the  synthesize  75°C One  to  used to  and  o x i d a t i o n of c e r t a i n  advisable to hinder  surface  the  of the p a r a f f i n  the  during  purification." T h i s we  d i d not  do,  and  i t may  p u r i f i c a t i o n at temperatureswe11 the  formation  of p r o d u c t s  the  sample we  were a t t e m p t i n g  be  that  o v e r 100°C r e s u l t e d I n  of o x i d a t i o n which to  repeated  purify.  contaminated  --96-APPENDIX  II  CALIBRATION OF HEXADECANE DILATOMETER TUBE  76.1775g  Mass o f m e r c u r y Volume o f m e r c u r y a t 50°G  5.654115g  Volume o f m e r c u r y a t 30°C  5 .633722,g,  D i f f e r e n c e i n volumes  o f mercury a t 50°C and 30°C  0.020393  C o r r e c t i o n f o r expansion of g l a s s = 30(5 .633722) (0.0000096)  0.001566p;  Net e x p a n s i o n o f m e r c u r y .  0.019311  Difference  3.120  i n mercury l e v e l s  cm.  A = c r o s s - s e c t i o n a l a r e a of tube = 0.019311/3.120  0.006163  (Average value o f A found over range  cm  0-80°C 0.006l75cm  range Volume o f b u l b t o 0 - p o i n t a t 3 0 C S  =  V  30  V  '= 3 0  "  h  A  = 5.633722-524.87550.0061755 5.48044  cc  2  2  —97— APPENDIX I I ( C o n t i n u e d ) C a l c u l a t i o n of d e n s i t y : t  = t e m p e r a t u r e a t w h i c h r e a d i n g was  h -  h e i g h t of mercury  taken  c o l u m n above z e r o  A = c r o s s - s e c t i o n a l area of c a p i l l a r y  clip  tube  V^ = volume o f t h e b u l b t o z e r o - p o i n t a t 30°C 0  h v^ = t o t a l volume o f m e r c u r y 0  t o h e i g h t h a t 30°C ~- V| - hA Q  = t o t a l volume t o h e i g h t h a t  t°C v| (t-30)(0.0000096),  V  = 30"  where 0 . 0 0 0 0 0 9 6 of g l a s s ,  i s the c o e f f i c i e n t of c u b i c a l expansion  (Pyrex)  W =• t o t a l mass o f m e r c u r y V.J. =• volume o f m e r c u r y  i n dilatometer with  i n dilatometer at  o r ( W ) ( s p e c i f i c volume o f mercury w ~ weight  t°C)  of t h e h y d r o c a r b o n i n d i l a t o m e t e r b u l b ,  =  t  hydrocarbon  t°C at  v^ =• volume o f h y d r o c a r b o n I n b u l b a t  D  Q  = d e n s i t y o f h y d r o c a r b o n a t t°C  =  t°C V  V  t ~ w/V  t  t  —98  —  APPENDIX I I ( C o n t i n u e d )  Example:  c a l c u l a t i o n of the density  t  = 30 C  h  = 26.55  o f h e x a d e c a n e a t 30°C  U  cm.  A = 0.006175  s q . cm.  hA = ( 2 6 . 5 5 ) ( 0 . 0 0 6 1 7 5 )  O.I638I  =  5.48044  V° 3o V  30  =  V  30 "  h  A  Z  5.48044 - 0.16381  5.64425  -  5.64425  (Since W = 63.6800  there  i s no c o r r e c t i o n f a c t o r )  g.  v £ = ( 0 . 0 7 3 9 5 5 2 ) (63.6800)  v  = v£  t  w D.  - V  = o'.7l67 z  w/v,  t  - 5.64425  4.70947  - 4.70947.. i  0.93478  g.  = 0.7167/0.93478  //  0.7666  —99 — APPENDIX I I I SPECIFIC  VOLUMES OF MERCURY FROM 0°C t o 95°C  The v a l u e s f r o m 0-40°C a r e t a k e n f r o m t h e C h e m i c a l E n g i n e e r s Handbook ( P e r r y ) , page 3 5 8 , and t h o s e  from  40-95°C a r e c a l c u l a t e d from t h e f o l l o w i n g e q u a t i o n : V  t  - 0 . 0 7 3 5 5 4 0 1 1 ->- 1 0  _ 6  (l8l.456t  0.000006608t  3  •+- 0 . 0 0 9 2 0 5 t  2  +0.000000067320t  Temp.  S p e c . Volume  Temp.  0.0 1.0 2.0 3-0 4.0  0.0735566 5694 5828 5961 6095  25.0 26.0 27.0 28.0 29.0  0.0738966 9036 9170 9304 9437  5.0 6.0 7.0 8.0 9-0  30.0 31.0 32.0 33*0 34.0  9571 9705 9839 9973 0.0740107  10.0 11.0 12.0 13.0 14.0  6228 6362 6496 6629 6763 6893 6893 7030 7164 7298 7431  35.0 36.0 37.0 38.O 39.0  0241 0374 0508 0642 0776  15.0 16.0 17.0 18.0 19.0  7565 7699 7832 7966 8100  40.0 41.0 42.0 43.0 44.0  0891 1024 1158 1223 1426  20.0 21.0 22.0 23.0 24.0  8233 8367 8501 8635 8768  45.0 46.0 47.0 48.0 49.0  1560 1695 1829 1963 2097  Spec.  Volume  4  &t)  --100--  APPENDIX I I I ( C o n t i n u e d ) Temp.  S p e c - Volume  Temp.  Spec. Volume  50.0 51.0 5210 53.0 54.0  0.0742231 2365 2500 2634 2768  75.0 76.0 77.0 78.0 79.0  0.0745087 5733 5868 5996 6130  55.0 56.0 57.0 58.0 59.0  2903 . 3037 3171 3305 3440  80.0 81.0 82.0 83.0 84.0  6264 6399 6535 6670 6804  60.0 61.0 62.0 63.0 64.0  3843 3709 3843 3978 4112  85.0 86.0 87-0 88.0 89.O  6939 7074 7209 7344 7479  65.O 66.0 67, 0 68.0 69.0  4246 4381 4516 4650 4785  90.0 91.0 92.0 93.0 94.0  7584 7749 7884 8019 8154  70.0 71. or ^2.0 73.0 74.0  4919 5053 5188 5322 5457  95-0  8288  :  7  —101 —  APPENDIX  IV  Hexadecane: Lower  Curve  0.7579  U p p e r C u r v e , same 8 5 C down t o 1 5 . 6 Temp. Density. 15.6 0.7765 0.8398 15.1 15.0 0.8465 0.8501 14.9 14.8 0.8526 14.7 0.8543 14.6 0.8556 14.5 0.8571 14.4 0.8584 0.8596 14.3 14.2 0.8607 14.1 0.8615 14.0 0.8625 0.8632 13.9  0.7637 0.7666  13.8 13.7 13.6  5  Temp. 85.6 84.0 82.0 78.0 76.0 74.0 70.0 66.0 62.0 58.0 54.0 50.0 46.0 42.0 38.0 34.0 30.0 28.0 26.0 24.0 22.0 20.0 18.0 17.0 16.0 15.6 15.0 14.9 14.8. 14.7 14.5  14.0 13.5 12.0 10.0 8.0 6.0 4.0 2.0 0.0  Density. 0.7264 0.7282 0.7294 0.7324 0.7336  0.7354 0.7383 0.7412 0.7440  0.7464 0.7496 0.7524 0.7552 O.7608  0.7681 0.7695 0.7709  13.5 13.1 13.0  0.7729  12.5  0.7736 0.7748  0.7761 0.7760 0.7765 0.8471  0.8536 0.8613 .  0.8707 0.8774  0.8937 : O.898I 0.9046 0.9080 0.9099 0.9109 0.9120 0.9129 0.9137  •  12.0 11.5 11.0 10.5 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0  0.8640  ,;  0.8651 0.8655 0.8661 0.8686 0.8691 0.8712 0.8743 0.8749 0.8759 0.8774 0.8781 0.8795 0.8810 0.8823 O.8836 0.8854 0.8864  0.8876 0.8890 0.8902 0.8916  --102--  APPENDIX I V ( C o n t i n u e d ) Elcosane:  Temp. 75.0 74.0 73.0 72.0 71.0 70.0 69.0 68.0 67.0 66.0 65.0 o4.0 03.O 62.0 61.0 60,0 59.0 58.0 57.0 56.0 55.0 54.0 53.0 52.0 51.0 70.0 49.0 48.0 47.0 46.0 45.0 44.0 43.0. 42.0 41.0 40.0 39.0 38.0 37.0 36.30  Density 0.7573 0.7581 0.7583 0.7587 0.7600 0.7601 O.7603 0.7609 0.7616 0.7620 0.7628 0.7635 0.7640 0.7631 0.7651 O.7656. 0.7661 0.7666 0.7675 0.7676 0.7686 0.7689. 0.7695 0.7699 0.7705 0.7712 0.7711 .0.7718 0.7726 0.7733 0.7735 0.7741 0.7749 0.7755 0.7748 0.7763 0.7771 0.7776 0.7782 0.7790'  Temp. 35-5 35-0 34.0 33.0 32.O 30.O 28.0 26.0 22.0 20.0 16.0 14.0 12.0 10.0. 8.0 4.0 0.0  Falling . Teirra. * 36.O 35.5 34.O 33.5 33.0 32.5 32.0 31.9 31.7 31.3  Density 0.8978 0.9065 0.9108 0.9108 0.9102 0.9102 0.9106 0.9124 0.9149 0.9159 0.9180 0.9190 0.9199 0.9207 0.9214 0.9229 0.9242  Temperature Density 0.8315 O.8525 0.862$ 0.8621 O.8654 0.8662 0.8677 0.8978 0.9060 0.9073  —103 —  APPENDIX I V  (Continued)  Docosane: L i q u i d Range  Temp. R i s i n g .  Temp.  Temp.  95.0 94.0 92.0 84.0 80.0 74.0 70.0 62.0 58.0 54.0 53.0 46.0 44.1  Density 0.7462 o.7466 0.7505 0.7531 0.7556 0.7596 0.7620 O.7672 O.7696 0.7721 0.7733 0.7785 0.7797  Temp. D r o p p i n g Temp. 43.5 43.0 42.0 41.0 40.0 39.8 39.6 39.4 39.0  Density  "  0.8596 0.8628 O.8650 0.8670 0.8690 0.8900 0.9012 0.9027 0.9039  43.4 43.0 42.8 42.4 42.0 4l.o 40.0 39.0 38.0 37.0 34.0 32.0 30.0 28.0 26.0 24.0 20.0 16.0 15.0 12.0 19.0 8.0 4.0 0.0  Density. 0.8882 0.8970 O.8989 0.9010 0.9022 0.9033 0.9040 0.9010 0.9029 0.9052 0.9081 0.9096 0.9108 0.9120 0.9138 0.9148 0.9173 0.9199 0.9200 0.9218 O.9227 O.9237 O.9251 0.9268  —104—  APPENDIX I V ( C o n t i n u e d ) Tetracosane: Temp.  Density.  7 5 .0 70 .0 65 . 0 60 . 0 55 .0 52 . 0 50 . 7 50 .6 50 . 5 50 .0 49 . 0 48 .3 48 .0 47 .8 47 .6 47 .5 47 .2 47 .1 46 .8 46 .6 46 .0 45 .0 42 .0 40 .0 3 5 .0 35 .0 30 . 0 25 . 0 20.0 15 . 0 10 . 0 5 .0  0 .7621 0 .7651 0 .7681 0 .7713 0.7744 0 .7764 0 .7772 0 .8468 0 .8601 0 .8616 0 .8648 0 .8658 0 .8663 0 .8722 0 .8932 0 .8939 0 .8974 0 .9136 0 .9147 0 .9172 0 .9205 0 .9306 0 .9322 0 • 9347 0 .934© •0 . 9 3 5 4 0. 9 3 7 0 0 .9386 0 .9399 0 .9397 ' 0.9409 0 .9420  — 105 —  APPENDIX I V ( C o n t i n u e d ) Hexacosane:  Temp. 90.0 80.0 70.0 •60.0 56.0 55.8 55.6 55.2 54.-8 54.5 54.0 53.0 52.0 51.0 50.0 48.8 48.6 48.2 48,. 0 47.0 46.0 44.0 40.0 36.0 32.0 ' 28.0 24.0 20.0 16.0 12.0 8.0 4.0 9.0  Density 0.7565 0.7642 0.7707 0.7768 0.7793 0.7796 0.8574 0.8607 0.8623 0.8634 0.8640 O.8658 0.8672 0.8688 0.8702 0.8722 0.8960 0.8992 0.9020 0.9055 O.906O 0.9071 0.9097 O.9120 0.9145 O.9169 0.9193 0.9219 0.9241 0.9266 O.9290 0.9313 0.9340  —106— Hexacosane:  (Capillary  Temperature R i s i n g . (Checked 4 times) Temp. H e i g h t •10.9 12 .0 16.0 20.0 24.0 28.0 32.0 36.0 40.0 42.0  8.00 8.28 9 .20 10.15 11.10 12.08 13.05 14.02 15 . 0 0 15.49  Temperature F a l l i n g (Following points .make smooth c u r v e w i t h those g i v e n above) Temp. 44.0 46.0 48.0' 49.0 50.0 51.0 51.5  52.0 52 .2 52.2 52.4 52.6 52.8 53.0 53.1 53.2 53.3 53.4 55.5 53.6 53.7 53.8 53.9 54.0 54.3 54.4 54.6 54.8 55.0  Height. 15.95 16.42 16.88 17.10 17.35 17.58 17.70 17.80 17.85 17.89 17-90 17.97 18.05 18.12 18.15 18.20 18.25 18.29 18.34 I8.38 1.8.42 18.49 18.55 18.61 18.75 18.88 19.03 19.21 19.39  Heights)  Temp.  Height  55 55 55 55 55 55.6 55.7 55.8 55-9 56.O  19.50 19.63 19.75 19.90 20.09 20.35 20.90 25.OO 28.60 28.60  Temperature R i s i n g 1 6 . 13 45. b 1 6 . 18 ' 46.0 .16. 2 0 46.5 1 6 . 24 47.0 16.. 28 47.5 1 6 . 34 48.0 16. 37 48.2 1 6 . 39 48.4 16. 48 49 . 0 16. 5 7 49.5 1 6 . 70 50.0 .16. 75 50.2 1 6 . 80 50.4 1 6 . 85 50.6 16. 91 50.8 1 7 . 00 51.0 17. 06 51.2 1 7 . 10 51.4 17. 16 51.6 17. 124 51.8 17. 33 52.0 1 7 . .40 52.2 17. • 4 9 52.4 17. • 5 8 52.6 17. 68 52.8 17. 78 53.0 17. 78 53.2 17. 53.4 98 18. 00 53.6 18. 24 53.8 18. 3 8 54.0 18. 54 54.2 18. 7 0 54.4 18. 88 54.6 1 9 . 08 54.8  --1Q7-Hexadosane:  ( C a p i l l a r y Heights, continued)  Temperature R i s i n g . Temp. 48.2 48.4 49.0 49.5 50.0 50.2 50.4 50.6 50.8 51.0  51.-2  51.4 51.6 51.8 52.0 52.2 52.4 52.6 52.8 53.0. 53.2 53.4 53.6 53.8 54.0 54.2 54.4 54.6 54.8 55.0.  55.2 55.4 55.6 56,0  Height. 16.37 16.39 16.48 16.57 16.70 16.75 16.89 16.85 16.91 -17.00 17.06 17.10 17.16 17.24 17.33 •. 17.40 17.49 17.58 • 17.68 17.78 17.78 17-98 18.10 18.24 18.38 18.54 18.70 18.88 19J38 • 19.34 19.56 19.85 20.35 28.60  R e a d i n g s Down f r om 95.0°C Temp. 47.2 47.3 48.0 49.2 51.0 52.0 52.0  Height • 14.1 p l u s •6.61  7.12 7.98 8.36 8.90 9.46  Temp. 52.5  53.0 53.5 54.0 54.5 55.0  Height. 9.78 10.17 10.65 11.26 12.00 13.16  Temperature F a l l i n g . C o n t i n u o u s , smooth c u r v e f r o m 95 C . Temo. 55-2 55.3 55.5 55.8 57.0 59.0 60.0 62.0 64.0 66.0 68.0 70.0 72.0 74.0 76.0 / 78.0 80.0 82.0 84.0 86.0 > 88.0 90.0 92.0 93.0 94.0 95.0  Height 14.24 15.19 18.00 28.60 28.88 29.35 29.59 30.08 30.55 31.025 31.61 32.00 32.50 32.99 33.57 33-98 34.47 34.97 35.45 B5 = 94 36.43 36.95 37.55 37.69 37.93 38.22  — 108 — APPENDIX I V ( C o n t i n u e d ) Octacoaane: Temperature  '  80.0 75.0 70.0 68.0 66.0 65.8 65.7 65.6 65.4 65.3 65.2 65.O 64.5 64.0 63.2 63.O 62.5 62.0 61.4 61.2 61.2 61.0 60.5 60.0 59.5 59.0 58.5 58.0 57.5 57.0 56.5 56.O 55.5 55.0 54.O 53-0 52.0 51.0 50.0 48.8 45.O 40.0 34.9 30.0 25.O 17.3 8.0 0.0  Density 0.7673 0.7705 0.7737 0.7751 0.7764 0.7765 0.7766 0.7767 0.7769 0.7769 0.7770 0.7771 0.7774 0.7778 0.7783 0.7785 0.7788 0.7791 0.7796 0.7797 0.8263 0.8335 0.8637 O.8676 0.8695 -0.8705 0.8712 0.8723 0.8,730 0.8737 0.8745 0.8751 0.8760 0.8769 0.8804 0.9073 0.9095 0.9099 0.9108 0.9117 0.9131 0.9159 0.9182 0.9204 0.9228 0.9263 0.9297 0.9324  — 109 —  APPENDIX IV ( C o n t i n u e d ) Nonacosane: Temperature 80.0 75-0 70.0 68.0 66.0 65.8 65.7 65.6 65-5 65.4 65.3 65.2 65.O 66.5 64.0 63.2 63.O 63.O 62.5 62.0 61.4 61.2 , 61.0 60.5 60.0 59.5 59.0 58.5 58.0 57.5 57.0 56.5 56.0 55.5 55.0 54.0 53.0 52.0 51-0 50.0 48.0 45.O 40.0 34.9: .30.0 25.0 17.3 8.0 0.0  Density 0.7696 0.7727 0.7760 0.7774 0.7785 0.7787 0.7788 0.7789 0.7790 0.7792 0.7793 0.7793 0.7795 0.7798 0.7800 0.7807 0.7825 0.7832 0.7936 0.7939 0.7952 0.7953 0.7953 0.7960 0.7968 0.7970 0.7970 0.7968 0.7983 0.7990 0.8088 0.8139 0.8143 0.8142 0.8142 0.8150 0.8179 0.8191 0.8199 0.8207 0.8224 0.8249 0.8282 0.8320 0.8371 0.7404 0.8450 0.8494 0.8523-  — H Q -  APPENDIX I V ( C o n t i n u e d ) Triacontane: Temp.  Dens i t y  80.0 75.0 70.0 68.0 66.0 65.8 65.7 65.6 65.5 65.3 65.3 65.3 65.2 65.0 64.5 64.0 63.2 63.O 62.5 62.0 61.4 61.2 61.0 60.5 60.0  0 .7731 0 .7763 0 .7795 0 .7808 0 .7819 0 .7821 0 .7822 0 .7822 0 .7823 0 .7824 0 .8098 0 .8160 0 .8612 0 .8689 0 .8720 0 .8731 0 .8743 0 .8746 0 . 8753 0 .8761 0 .8771 0 .8774 0 .8777 0 .8784 0.8801  Temp. 59.5 59.0 58.5 58.0 57.5 57.0 56.5 56.0 55.5 55.0 54.0 53.0 52.0 51.0 50.0 48.0 45.0 40.0 54.9 30.0 25.0 17-3 8.0 0.0  Density. 0.9172 0.9214 0.9236 0.9238 0.9242 0.9246 0.9243 0.9253' O.9256 O.9259 0.9270 0.9275 0.9280 O.9285 0.9291 0.9305 0.9321 0.9350 0.9372 0.9396 0.9423 0.9453 0.9488 0.9512  " I l l - AppENDIX  IV  (Continued)  Dotriacontane: Temp. 86.75 80.08 75.0 73.0 71.0 69.I 68.1 67.O 66.0 65.O 63-95 63.5 63.O 62.5 . 62.4 62.24 62.0 60.0 55.0 47-6  .  42.8 49.95 45.12 40.12 35.03 30.6 24.7 21.2 15.4 9.25 0.10  Density. 0.7715 0.7756 0.7787 O.7801 0.7816 0.7827 0.8628 0.8708 0.8738" • 0.8758 0.8780 0.8780 O.8885 0.9080 0.9102 0.9113 0.9122 0.9156 0.9208 0.9271 0.9329 0.9300 O.9252 0.9286 0.9310 0.9345 0.9366 0.9293 0.9399 0.9450 0.9445 0.9471  --112-APPENDIX I V  (Continued)  Tetratriacontane: Temperature. 95-0 90.0 85.0 80.0 74.0 72.9 72.4 72.2 72.0 71.8 71.6 71.4 71.2 71.0 70.5 70.0 69.0 68.2 68.0 67.5 67.0 66.5 66.0 64.0 62.0 60.0 55.0 50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0  Dens i t y . 0.7716 0.7751 0.7781 0.7810 0.7847 0.7853 0.8550 O.865O 0.8686 0.8716 0.8734 0.8748 0.8760 0.8770 0.8788 0.8798 0.8820 O.8836 0.9040 0.9136 0.9170 ' 0.9192 0.9206 0.9232 0.9249 0.9260 0,<9292 0.9320 0.9348 0.9370 0.9397 0.9422 0.9443 0.9468 0.9486 0.9502 0.9519 0.9520  

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