Q. Adsorption of a gas on solid metal surface is spontaneous and exothermic, then :
A) $H$ increases
B) $S$ increases
C) $G$ increases
D) $S$ decreases
Explanation
(d)
Since for spontaneous and exothermic process $\mathrm{\Delta}G = \ - ve,\ \ \mathrm{\Delta}H = \ - ve$ at all temperatures, therefore from $\mathrm{\Delta}G = \ \mathrm{\Delta}H - T\mathrm{\Delta}S,\ \mathrm{\Delta}S$ should be $- ve.$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.