For a gaseous reaction where the number of product moles exactly equals the number of reactant moles — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

The relationship between enthalpy and internal energy is $\Delta H = \Delta U + \Delta n_g RT$. If there is no net change in the number of moles of gas ($\Delta n_g = 0$), the expansion work term drops out, leaving $\Delta H = \Delta U$.