Given the following data: S(g)+ O₂(g)→ SO₂(g) Δ_rG° = -300.1 kJ/mol-rxn 2 S(g)+ 3 O₂(g)→ 2 SO₃(g) Δ_rG° = -742.1 kJ/mol-rxn Calculate Δ_fG° for the reaction below. SO₂(g)+ 1/2 O₂(g)→ SO₃(g) A) -1042.2 kJ/mol-rxn B) -71.0 kJ/mol-rxn C) +2.47 kJ/mol-rxn D) +71.0 kJ/mol-rxn E) +1042.2 kJ/mol-rxn

Question

Quizplus · Accepted Answer

Using Hess's Law, we can find Δ_fG° for the given reaction by manipulating the given equations: S(g)+ O₂(g)→ SO₂(g) Δ_rG° = -300.1 kJ/mol-rxn 2 S(g)+ 3 O₂(g)→ 2 SO₃(g) Δ_rG° = -742.1 kJ/mol-rxn ----------------------------------------- SO₂(g) + 1/2 O2(g) → SO₃(g) Δ_fG° = ? We need to reverse the first equation and divide the second equation by 2 to match the reactants and products in the desired equation: SO₂(g) → S(g)+ O₂(g) Δ_rG° = +300.1 kJ/mol-rxn (2/3) SO₃(g)+ (1/2) O2(g) → (1/3) SO₂(g) Δ_rG° = +371.05 kJ/mol-rxn Now, we can add these two equations together to cancel out SO₂(g) and get the desired equation: (2/3) SO₃(g) → S(g) + (1/2) O2(g) Δ_fG° = -71.0 kJ/mol-rxn Therefore, the answer is B, -71.0 kJ/mol-rxn.

Given the Following Data: S(g)+ O2(g)→ SO2(g)

Given the Following Data: S(g)+ O₂(g)→ SO₂(g)