Question

Identify the incorrect statements from the following: I. $\Delta S_{\text{system}} = (\Delta S_{\text{total}} + \Delta S_{\text{sur}})$ II. $A(l) \rightarrow A(s)$; for this process entropy change decreases III. Entropy units are $J \ K^{-1} \ mol^{-1}$

• A. I, III only
• B. I, II only
• C. I, II, III
• D. II, III only

Hint:

Always use the correct entropy equation: $\Delta S_{\text{total}} = \Delta S_{\text{system}} + \Delta S_{\text{surroundings}}$.

Answer 1

The Correct Option is A

Step 1: Analyzing Statement I The correct entropy relation is: $$\Delta S_{\text{total}} = \Delta S_{\text{system}} + \Delta S_{\text{surroundings}}$$ Thus, the given equation is incorrect. Step 2: Analyzing Statement II When a liquid changes to a solid, the molecular disorder decreases, leading to a decrease in entropy. This statement is correct. Step 3: Analyzing Statement III The SI unit of entropy is $J \ K^{-1}$ (not necessarily per mole). Thus, the given unit is misleading, making this statement incorrect.