CHEMISTRY: J. B. FERGUSON 
373 
TABLE 2 
Equilibrium Approached prom the CO2-S2 Side 
TEMPERATURES 
Absolute Centigrade 
1277 1004 
1458 1185 
1463 1190 
TABLE 3 
TEMPERATURE 
Absolute 
r CALCULATED 
1271 
3.88 
1273 
4.12 
1273 
3.94 
1277 
3.85 
1458 
3.97 
1463 
3.96 
1463 
4.00 
Average value = 
3.96 
The agreement speaks not only for the results themselves, but justi- 
fies the assumption of — 34195 cal. for A^Tq for the reaction, | (Sr + O2 
= SO2) and indicates the correctness of Berthelot's value for the heat 
of formation of sulphur dioxide. The free energy equations for the two 
reactions 
CO + i SO2 = = = CO2 + I S2 and 
+02= = = SO2 
may now safely be written. 
The former will be 
AFo= - 25 915 + 1.375 TlnT - 0.0014^ + 0.000000155r^ + 3.96r 
and the latter 
AFo= - 68 391 + 3.62rinr - 0.0007 + 0.000 000 31 7 7^-25.037 
Under standard conditions, therefore, 
CO + I SO2 = CO2 + i S2 AF298 = - 22 529 cal 
Sr + O2 = SO2 AF298 = - 69 757 cal.7 
The final paper will appear in the Journal of the American Chemical 
Society. 
1 Lewis, G. N. and Lacey N. /. Amer. Chem. Soc, Easton, Pa., 37, 1915, (1976) 
2 Lewis, G. N. Ihid., 35, 1913, (1). 
3 Lewis, G. N. and Randall, M. Ihid., 34, 1912; (1128), 36, 1914, (2468); 37, 1915, (465). 
4 Ann. chim. phys., Paris, (Ser. 5), 22, 1881, (428). 
^ Berthelot's average value of 69260 includes results obtained from experiments in which 
the sulfur dioxide was determined by means of an alkaline solution. This procedure prob- 
LogK 
1.78 
1.27 
1.18 
