#methanol formation

Calculate Δ H for C(s) + H₂(g) + O₂(g) → CH₃OH(l) given: CH₃OH(l) + (3/2)O₂(g) → CO₂(g) + 2H₂O(l), Δ H = -726.5 kJ/mol;

Reverse first: Δ H = 726.5 kJ. Second: Δ H = -393.5 kJ. Third (×2): Δ H = -571.6 kJ. Add: 726.5 - 393.5 - 571.6 = -238.6 kJ/mol.

Ref: NCERT Class 11 Chemistry > Chapter 5: Thermodynamics > Topic: Third Law of Thermodynamics and Applications