Question

For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature on its equilibrium constant Kin terms of change in entropy is described by
A. With increase in temperature, the value of K for exothermic reaction decreases because the entropy change of the system is positive.
B. With increase in temperature, the value of K for endothemic reaction increases because unfavourable change in entropy of the surrounding decreases
C. With increases in temperature, the value of K for exothermic reaction decreases because because favourable change in entropy of the surroundings decreases
D. With increases in temperature, the value of K for endothemic reaction increases because the entropy change of the system negative.

Answer 1

Correct Answer - B::C
For endothermic reactions: `DeltaH=+ve` therefore, equilibrium constant increases with temperature.
`log((K_(1))/(K_(2)))=(DeltaH)/(2.303R)[(1)/(T_(1))-(1)/(T_(2))]`
`DeltaS_(surr)=-(q_("system"))/(T)`
`DeltaS_(surr) lt `0 for endothermic process thus decrease in entropy of surroudings is unfavourable. For exothermic reaction, equilibrium constant will decreases with rise in temperature `DeltaS_(surr) lt0` (for exothermic process which is favourable for surroundings).