Question

202.8 A scientist measures the standard enthalpy change for the following reaction Fe304) + 4 Hy()_3Fe(s) + 4 H 0(e) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of Fe,O_is kJ/mol. Submit Answer Retry Entire Group B more group attempts remaining

Answer 1

Given:

ΔHo rxn = 202.8 KJ/mol

Hof(H2(g)) = 0.0 KJ/mol

Hof(Fe(s)) = 0.0 KJ/mol

Hof(H2O(g)) = -241.818 KJ/mol

Balanced chemical equation is:

Fe3O4(s) + 4 H2(g) ---> 3 Fe(s) + 4 H2O(g)

ΔHo rxn = 3*Hof(Fe(s)) + 4*Hof(H2O(g)) - 1*Hof( Fe3O4(s)) - 4*Hof(H2(g))

202.8 = 3*(0.0) + 4*(-241.818) - 1*Hof(Fe3O4(s)) - 4*(0.0)

Hof(Fe3O4(s)) = -1170.072 KJ/mol

Answer: -1170.07 KJ/mol