JEE PYQ: Thermodynamics Question 1
Question 1 - 2021 (17 Mar Shift 2)
During which of the following processes, does entropy decrease?
(A) Freezing of water to ice at $0^\circ$C (B) Freezing of water to ice at $-10^\circ$C (C) $\text{N}_2(g) + 3\text{H}_2(g) \to 2\text{NH}_3(g)$ (D) Adsorption of CO(g) and lead surface (E) Dissolution of NaCl in water
(1) (A), (B), (C) and (D) only
(2) (B) and (C) only
(3) (A) and (E) only
(4) (A), (C) and (E) only
Show Answer
Answer: (1)
Solution
(A) Water $\xrightarrow{0^\circ\text{C}}$ ice; $\Delta S = -\text{ve}$. (B) Water $\xrightarrow{-10^\circ\text{C}}$ ice; $\Delta S = -\text{ve}$. (C) $\text{N}_2(g) + 3\text{H}_2(g) \to 2\text{NH}_3(g)$; $\Delta S = -\text{ve}$. (D) Adsorption; $\Delta S = -\text{ve}$. (E) $\text{NaCl}(s) \to \text{Na}^+(aq) + \text{Cl}^-(aq)$; $\Delta S = +\text{ve}$.
BETA
