CHM112 Home Page Reference Materials Homework Assignments Lectures Exams & Quizzes Grades Study Aids URI Home Page


J. W. Hill, R. H. Petrucci, T. W. McCreary, & S. S. Perry General Chemistry 4th edition

Problem 17.40

Use the data from Appendix C to determine Go values for the following reactions at 25 oC.

(a) C2H4(g) + H2(g) C2H6(g)

(b) SO3(g) + CaO(s) CaSO4(s)




Answer:

In general,at 25 oC, Go can be found from


(a) C2H4(g) + H2(g) C2H6(g)

Gfo(C2H6(g)) = –32.89 kJ/mol

Gfo(H2(g)) = 0.00 kJ/mol

Gfo(C2H4(g)) = 68.12 kJ/mol

so Go = [–32.89] – [68.12 + 0.00] = –101.01 kJ

(b) SO3(g) + CaO(s) CaSO4(s)

Gfo(CaSO4(s)) = –1322 kJ/mol

Gfo(CaO(s)) = –604.0 kJ/mol

Gfo(SO3(g)) = –371.1 kJ/mol

so Go = [–1322] – [–604.0 + –371.1] = –347 kJ