Question

Identify the correct statements from the following:
I. At 0 K, the entropy of pure crystalline materials approaches zero.
II. Entropy for the process $ \text{H}_2\text{O(l)} \rightarrow \text{H}_2\text{O(g)} $ decreases.
III. Gibbs energy is a state function.

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

Hint:

Entropy increases when a system becomes more disordered. Gibbs energy is a state function, and at 0 K, entropy of a perfect crystal is zero.

Answer 1

The Correct Option is B

- Statement I is correct: By the Third Law of Thermodynamics, entropy of a pure crystalline substance approaches zero as \( T \rightarrow 0\, \text{K} \).
- Statement II is incorrect: In the process \( \text{H}_2\text{O(l)} \rightarrow \text{H}_2\text{O(g)} \), entropy increases because gas is more disordered than liquid.
- Statement III is correct: Gibbs free energy \( G \) is a thermodynamic state function dependent only on initial and final states.