Can a process be spontaneous if the entropy of the system definitively decreases ()? — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Spontaneity is judged strictly by $\Delta S_{universe}$, not $\Delta S_{sys}$ alone. For example, freezing water at -10 C creates a highly ordered state ($\Delta S_{sys} < 0$), but the latent heat released warms the surroundings enough to make $\Delta S_{univ} > 0$.