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

💡 Solution & Explanation

Spontaneity is judged strictly by the universe's entropy ($\Delta S_{univ} > 0$), 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 $\Delta S_{univ} > 0$.