Carbonyl sulfide (COS) is a trace component in the atmosphere. One difficulty in studying chemical reactions of this molecule is that it spontaneously decomposes into carbon dioxide (CO2) and carbon disulfide (CS2) by the process.
2 COS(g) -----> CO2(g) + CS2(g)
Thermochemical data for the substances involved in this reaction are given below.
Compound ?H°f(kJ/mol) ?G°f (kJ/mol) S° (J/mol.K)
CO2(g) - 393.5 - 394.4 213.8
CS2(g) 116.9 66.8 238.0
COS(g) - 138.4 -165.6 231.6
a) What are ?S°syst, ?S°surr, and ?S°univ, for the above reaction?
b) What is the numerical value for Keq for the above reaction?