The enthalpy of formation of ammonia gas is –46.0 kJ/mol. The enthalpy change for the reaction:<br> — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

The given reaction is the exact reverse of the formation reaction for 2 moles of ammonia. $\Delta H = -2 \times \Delta H_f = -2 \times (-46.0\text{ kJ/mol}) = +92.0\text{ kJ}$.