In any spontaneous process,
A
Only F decreases
B
Only A decreases
C
Both F and A decreases
D
Both F and A increase
Correct Answer: Both F and A decreases
For any spontaneous process there should be finite changes so, we can consider it as an irreversible process and we know for irreversible process from second law of thermodynamics $$TdS - dU - PdV > 0$$Under constant temperature and volume process $$ - dF > 0 \Rightarrow dF Similarly for an constant temperature and pressure process
$$\eqalign{ & d\left( {TS - U - PV} \right) > 0 \cr & \Rightarrow dG = 0 \cr} $$
