Using Hess’s law, calculate Δ H for 2S(s) + 3O₂(g) → 2SO₃(g) given: S(s) + O₂(g) → SO₂(g), Δ H = -296.8 kJ/mol; 2SO₂(g)
Multiply first by 2: 2S(s) + 2O₂(g) → 2SO₂(g), Δ H = -593.6 kJ. Add second: Δ H = -593.6 + (-197.8) = -791.4 kJ.
Ref: NCERT Class 11 Chemistry > Chapter 5: Thermodynamics > Topic: Heat Capacity and Calorimetry and Measurement of Enthalpy
