GO 



THE TRUE VALUE OF a OP VAN DER WAALS' 



C 2 H 2 



<v/ 6 



a '. 



so 2 .... 



Methyl formate . . , 



Br,". 



cs 2 



Ethyl formate 



Methyl acetate. . . , 



Ether 



n-Pentane. ...*... 



i-Pentane 



Benzene 



Propyl formate. . . , 



Ethyl acetate 



Methyl propionate . 



cci A . 



I [exaniethylene. . . . 



n-llexane 



Diisopropyl 



Chlor- benzene. 



Methyl butyrate. . . 

 Methyl isobutyrate, 

 Propyl acetate . . . . 

 Ethyl propionate . . 



Sn Cl 4 



n-IIeptane 



n-Octane 



Diisobutyl 



Mesitylene 



( y mené 



Diisoamyl 



Log -a 



Log {MX Val) 



Val X M 



12.713 



2.4150 



10X20 



12.827 



2.0232 



14X30 



12.884 



2.0290 



6 X70.9 



12.889 



2.7093 



8X64 



13.062 



2.9823 



10X60 



13.090 



2.9819 



0X159.84 



13.125 



3.0849 



10X^6 



13.208 



8.2116 



22X74 



13.190 



3.2110 



22X74 



13.270 



3.3104 



28X74 



13.320 



3.3025 



32X72 



13.311 



3.3025 



32X72 



13.3158 



3.3092 



30X78 



13.330 



3.3910 



28X88 



13.311 



3.3910 



28X88 



13.316 



3.3910 



28XS8 



13.353 



3.3911 



10X153.8 



13.393 



3.4800' 



30X84 



13.419 



3.5143 



38 X86 



13.410 



3.5143 



38X86 



13.445 



3.5501 



32X112.45 



13.410 



3.5401 



34X162. 



13.408 



3.5401 



34X102 



13.415 



3.5401 



,34X102 



13.413 



3.5401 



•■MX 102 



13.478 



3.0204 



10X260.8 



13.509 



3.0434 



44X100 



13.590 



3.7559 



50X114 



13.574 



3.7559 



50X114 



13.573 



3.700S 



48X120.1 



13.048 



3.8598 



54X134.1 



13.722 



3.9452 



02X142.18 



The agreements between the values computed from the valences 

 and molecular weight with those computed from the critical pres- 



') In CS-2 I have used for a the mean value of' 13.33 X 10 1 " in place of « as com- 

 puted by the formula: » = G.5 PcV," since the latter value is plainly erroneous owing 

 tn the critical density being wrong. Bi^ mesitylene, cymene and diisoamyl have a deter- 

 mined from the surface tension. Oxygen is taken every where as bivalent, hence the 

 exceptional position of some of the oxygen compounds. CI ami l!r are everywhere com- 

 puted as trivalent. Carbon and tin are tetravalent, except C in CO, where it is divalent. 

 S is liexavalent except in SO., where it is tetravalent. 



