Which of the following conceptual statements concerning thermodynamic entropy () are definitively co — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

(A) Free expansion is entirely irreversible; volume expands without heat exchange, driving up microstates and systemic entropy ($\Delta S > 0$). (B) Reversible adiabatic mathematically implies $q_{rev} = 0$, so $\Delta S = q_{rev}/T = 0$ (isentropic). (C) Reversible processes perfectly maintain system-surrounding equilibrium everywhere, enforcing $\Delta S_{univ} = 0$. (D) Irreversible adiabatic expansions autonomously generate entropy; $\Delta S_{sys}$ must be strictly positive, not negative.