Equal volumes of one molar hydrochloric acid and one molar sulphuric acid are neutralized completely — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Equal volumes of 1 M solutions mean there are equal moles of the parent acids. However, $\text{H}_2\text{SO}_4$ is dibasic, providing twice as many moles of $\text{H}^+$ ions for neutralization as the monobasic HCl. Since the heat of neutralization is proportional to the moles of water formed, the heat liberated by sulphuric acid ($Y$) is twice that of hydrochloric acid ($X$), hence $Y = 2X$.