will be highest for the reaction — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Entropy change is largely dictated by the change in the number of gaseous moles ($\Delta n_g$). For (a) $\Delta n_g = -0.5$. For (b) $\Delta n_g = +1$. For (c) $\Delta n_g = 0$. For (d) $\Delta n_g = 0$. Reaction (b) has the maximum positive $\Delta n_g$, hence highest $\Delta S$.