Question

Part A

Calculate the enthalpy of the reaction

2NO(g)+O2(g)→2NO2(g)

given the following reactions and enthalpies of formation:

12N2(g)+O2(g)→NO2(g),   ΔfH∘A=33.2 kJ mol−1

12N2(g)+12O2(g)→NO(g),  ΔfH∘B=90.2 kJ mol−1

Express your answer with the appropriate units.

Part B

Calculate the enthalpy of the reaction

4B(s)+3O2(g)→2B2O3(s)

given the following pertinent information:

B2O3(s)+3H2O(g)→3O2(g)+B2H6(g),   ΔrH∘A=+2035  kJ mol−1

2B(s)+3H2(g)→B2H6(g),                        ΔrH∘B=+36  kJ mol−1

H2(g)+12O2(g)→H2O(l),                     ΔrH∘C=−285  kJ mol−1

H2O(l)→H2O(g),                                    ΔrH∘D=+44  kJ mol−1

Express your answer with the appropriate units.

Answer 1