Question

A spontaneous process is one in which the system suffers :

• A. no energy change
• B. a lowering of free energy
• C. a lowering of entropy
• D. an increase in internal energy

Hint:

At constant temperature and pressure, spontaneity requires \(\Delta G <0\).

Answer 1

The Correct Option is B

Step 1: Condition of spontaneity at constant \(T, P\).
A process is spontaneous when Gibbs free energy decreases:
\[ \Delta G<0 \]
Step 2: Meaning of lowering of free energy.
Lower free energy means system has more tendency to move toward equilibrium and stability.
Step 3: Match with options.
Option (B) directly corresponds to decrease in Gibbs free energy.
Final Answer:
\[ \boxed{\text{(B) a lowering of free energy}} \]