EQUATION AND THE NATURE OF COHESION. 45 



23. Ethyl acetate. C±H % % . 



[a), a = 2.03 UT r F,/\ .03 — P C V 2 . T r = 523.1 ; d c = . 3077; 



P c = 28.877 mm.Hy, V r =280 a = 21.88 X 10 12 



{b). a = 0.5 P C V 2 a = 20.47 X I0' 2 



( c ). a = pM 2 /3 d;-'\ M = 88.00; // = 98.0. . a = 23.23 X I0 X2 



(d). a = C'BT K r c . C' = 1.812 a = 22.56 X 10' 2 



(«?). a = 3 MN Ui T r Cjd,. (7=2.10 ( Morg an 



and Schwartz, Lohnstein) d = 1 .2 1 01 a = 20.78 X '0 1 - 

 Ramsay and Aston found for C at — 89.2° the value 

 2.24. This would give for a the value 21.54 X 10 12 . 

 These results do not agree very well, but their mean is 21.68 X 10 ' 2 . 

 a computed from the valences and molecular weight, with 28 valen- 

 ces in the molecule, namely 10 for carbon, 4 for the oxygen and 

 8 for the hydrogen, is 21.46 X W 2 - This i s m excellent agreement 

 with the mean value. Van Laar gives for a, when computed to 

 dynes in gram mol quantities, the value 20.40. 



24. Propyl formate. C' e II H 2 . 



(a), a = 2.03 RT r V r \\A)3 — P r V 2 . T r = 537.S5 ; P c = 30.400 

 mm.Hg. ; d c = . 3003; V,. = 284.5 . . . a = 21.79 X 10 2 



(b). ö= i 6.5P/ c 2 a = 21.37 X 10' 2 



(c). a = ^'J/ 2 /3 d, 2 \ M = 88; // = 08.70 . . . a = 23.33 X I0 12 



(d). a = CUT r V,. C' = 1.774 a = 22.57 X 10' 2 



(e). a = 3MN^ T/'/d„. C= 2.11 (Ramsay and 



Aston). < v = 1 . 1 7 G a = 21.56X10 12 



The latent heat values are much higher than the other three and 

 bring the average to 22.12 X 10 12 - ^ ne value required from the 

 valences and weiedit is 21.46 if there are 28 valences in the mole- 



's' 



cule. This agrees well with the three values other than the latent 



"Ö 



heat values, but is considerably lower than the latter. 



2 5 . Methyl propiona te. 6' 4 U 8 2 . 



(a), a = 2.03 PT r f r J\. 03 — P,.F r . P,. = 30.032 ; d c = . 3124 ; 



M = 88.06; 7]. = 530.4; V t . = 28 1.9 a = 21.32 X 10' 2 



(Ó). a = 0.5 P,.F 2 _ a = 2 o.68 X 10' 2 



(c). a = [xM 2 /3 d c -'*. //' = 99.02 a = 23.27 X N>' 2 



(d). a = CllT v F r . G' = 1.S03 a = 22.42 X 10' 2 



(e). a =3 MN^T r Cjd . ^ = 1.225 6'= 2.18 

 (Morgan and Schwartz corrected after 



Lohnstein method) a = 21.11 X 1<> 12 



