Question

Condition for spontaneity in an isothermal process is

• A. \( \Delta A + \Delta U \leq 0 \)
• B. \( \Delta G \leq 0 \)
• C. \( \Delta A + \Delta U>0 \)
• D. \( \Delta G>0 \)

Hint:

For a process to be spontaneous, the change in Gibbs free energy must be negative.

Answer 1

The Correct Option is B

Step 1: Spontaneity criterion.
In an isothermal process, for spontaneity, the change in Gibbs free energy \( \Delta G \) must be negative, i.e., \( \Delta G \leq 0 \). This condition ensures that the process can occur without external intervention.

Step 2: Conclusion.
Thus, the correct answer is option (B).

Final Answer: \[ \boxed{\text{(B) } \Delta G \leq 0} \]