Question

Which of the following chemical equations is the formation reaction of Fe2O3(s) from its constituent elements in their standard states? The standard enthalpy of formation (∆Hfo) values are given in the table below.

Substance ∆Hfo (kJ/mol)

Fe(s) 0 O2(g)

0 O3(g) 142.7

FeO(s) −272.0

Fe2O3(s) −824.2

A) 4 Fe(s) + 3O2(g) 2Fe2O3(s)

B) 2 Fe(s) + O2(g) Fe2O3(s)

C) 2 Fe(s) + O3(g) Fe2O3(s)

D) Fe2O3(s) 2Fe(s) + O2(g)

E) 2 FeO(s) + O2(g) Fe2O3(s)