Question

Consider the oxidation of no to no2: no(g)+12o2(g)→no2(g) calculate δg∘rxn at 25∘c. express the free energy change in kilojoules to three significant figures

Answer 1

Given reaction is NO(g)+1/2 O₂(g)→NO₂(g)

ΔGf⁰ [NO₂(g)] = 51.9 kJ/mol

ΔGf⁰ [NO(g)] = 86.6 kJ/mol

ΔGf⁰ [O2(g)] = 0 kJ/mol

ΔG⁰rxn = ΔGf⁰(products) - ΔGf⁰( reactants)

= ΔGf⁰ [NO₂(g)] - {ΔGf⁰ [NO(g)]+ (1/2) ΔGf⁰ [O₂(g)]}

= 51.9 kJ/mol - { 86.6 kJ/mol + 0}

= -34.7 kJ/mol

Therefore, ΔG⁰rxn = -34.7 kJ/mol