Question

Which is true when ΔS is positive and ΔH is positive?
A. A process is spontaneous only at high pressures.
B. A process is spontaneous only at high temperatures.
C. A process is spontaneous only at low pressures.
D. A process is spontaneous only at low temperatures.

Could the answer be D? I am not sure. I know that when ^H is positive, the reaction is endothermic. An explanation would be greatly appreciated :).

Answer 1

\[DeltaG = DeltaH-TDeltaS\] I believe that delta G is at constant pressure; so the first one would not really apply. if delta H > 0 and delta S > 0

thing is we don't know much about how big the sign's are like we know both H > 0 and S >0 BUT WE don't know if either one is bigger. the most important thing is that we know delta G has to be less than zero for the process to be spontaneous. that would mean that TDELTAS would have to be bigger than H. The only way this could happen is at high temperatures because -TDELTA S would be large and negative and this would be greater than H. so when we subtract them it will be negative.