Spontaneity of Chemical reactions

Answer

A spontaneous process occurs naturally without external help once started. Example: Rusting of iron — iron reacts with oxygen and moisture to form rust (Fe₂O₃) without any continuous external input.

Answer

Hot water loses heat to the cooler surroundings until thermal equilibrium is reached. This happens naturally due to temperature difference, so it’s spontaneous. The reverse (water heating up by absorb…

Answer

Entropy (S) is a thermodynamic property that measures the degree of randomness or disorder in a system. Higher disorder means higher entropy. For example, gases have more entropy than liquids, which h…

Answer

H₂O(s) < H₂O(l) < H₂O(g). Solid water (ice) is most ordered (lowest entropy), liquid has moderate disorder, and gas has maximum randomness (highest entropy).

Answer

The entropy change is given by: $$ \Delta S = \frac{q_{\text{rev}}}{T} $$ where $ q_{\text{rev}} $ is the heat transferred reversibly and $ T $ is the absolute temperature in Kelvin.

Answer

Given: - $\Delta_{\text{fus}}H = 6.02\,\mathrm{kJ\,mol^{-1}} = 6020\,\mathrm{J\,mol^{-1}}$ - $T = 273\,\mathrm{K}$ $$ \Delta_{\text{fus}}S = \frac{\Delta_{\text{fus}}H}{T} = \frac{6020}{273} = 22.05\…

Answer

Given: - $\Delta_{\text{vap}}H = 40.8\,\mathrm{kJ\,mol^{-1}} = 40800\,\mathrm{J\,mol^{-1}}$ - $T = 373\,\mathrm{K}$ $$ \Delta_{\text{vap}}S = \frac{\Delta_{\text{vap}}H}{T} = \frac{40800}{373} = 109.

Answer

The second law states that for any spontaneous process, the total entropy of the universe increases: $$ \Delta S_{\text{univ}} = \Delta S_{\text{sys}} + \Delta S_{\text{surr}} > 0 $$ At equilibrium, $…