A chemical reaction will occur spontaneously at constant pressure and temperature, if the free energy is

A. Zero

B. Positive

C. Negative

D. None of these

Answer: Option C

Solution(By Examveda Team)

Since for an spontaneous process $$TdS > dU + PdV$$
For, constant temperature and constant pressure process the above equation can be written as
$$\eqalign{ & d\left( {TS - U} \right) > PdV \cr & \Rightarrow d\left( { - A} \right) > PdV \cr & \Rightarrow {\left( {dG} \right)_{T,P}} < 0 \cr} $$
For spontaneous process.