Consider the following table of thermodynamic data. All values are tabulated at
ID: 798092 • Letter: C
Question
Consider the following table of thermodynamic data. All values are tabulated at 250C.
Substance: C2H2 (g) deltaGf0 (kJ/mol)=209 deltas0 (j/mol.K)=201
Substance: C2H4 (g) deltaGf0 (kJ/mol)=68 deltas0 (j/mol.K)=219
Substance: C2H6 (g) deltaGf0 (kJ/mol)=-33 deltas0 (j/mol.K)=230
Substance: H2O (g) deltaGf0 (kJ/mol)=-229 deltas0 (j/mol.K)=189
Substance: C2H5OH (l) deltaGf0 (kJ/mol)=-175 deltas0 (j/mol.K)=161
The value of deltaS0 for the following reaction is - 233J/K at 250C. What is the entropy of H2 (g) at 250C?
C2H2 (g) + 2H2 (g) ----> C2H6 (g)
Explanation / Answer
C2H2 (g) + 2H2 (g) -------> C2H6 (g)
(201) .... (2) (? S) ----> (230)
dS = prod - reactants
-233kJ = 230 - [(201) & (2)(S of H2)]
-463 = -201 - 2S of H2
- S of H2 = -262
S of H2 = 131 Joules