#ethanol decomposition

Calculate Δ H for C₂H₅OH(l) → C₂H₄(g) + H₂O(l) using: Δ Hf° (C₂H₅OH,l) = -277.7 kJ/mol, Δ Hf° (C₂H₄,g) = 52.3 kJ/mol, Δ

Δ H = [Δ Hf° (C₂H₄) + Δ Hf° (H₂O)] - Δ Hf° (C₂H₅OH) = [52.3 + (-285.8)] - (-277.7) = -233.5 + 277.7 = 44.2 kJ/mol.

Ref: NCERT Class 11 Chemistry > Chapter 5: Thermodynamics > Topic: Enthalpy Changes - Reaction Formation Combustion and Hess's Law