Question

For the process \( H_2O(g) \, (1 \, \text{bar}, 373 \, \text{K}) \rightarrow H_2O(g) \, (1 \, \text{bar}, 373 \, \text{K}) \), the correct set of thermodynamic parameters is:

• A. \( \Delta G = 0 \), \( \Delta S = +ve \)
• B. \( \Delta G = 0 \), \( \Delta S = -ve \)
• C. \( \Delta G = +ve \), \( \Delta S = 0 \)
• D. \( \Delta G = -ve \), \( \Delta S = +ve \)

Hint:

In reversible processes at constant temperature, the Gibbs free energy change is zero. Entropy change depends on the direction of the reaction.

Answer 1

The Correct Option is B

Step 1: The process is an isothermal and reversible reaction. Since no temperature change is involved, the entropy change is zero.
Step 2: The Gibbs free energy change is zero because the process is in equilibrium. \( \Delta G = 0 \), and \( \Delta S = -ve \).

Final Answer: \[ \boxed{\Delta G = 0, \Delta S = -ve} \]