Heat liberated by a given amount of an ideal gas undergoing reversible isothermal process is 1200 ca — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

For an ideal gas undergoing an isothermal process, $\Delta H = 0$. From the definition of free energy, $\Delta G = \Delta H - T\Delta S = -T\Delta S$. For a reversible process, $\Delta S = q_{\text{rev}}/T$, so $\Delta G = -q_{\text{rev}}$. Because heat is liberated, $q_{\text{rev}} = -1200 \text{ cal}$, rendering $\Delta G = +1200 \text{ cal}$.