For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature…

For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature on its equilibrium constant K in terms of change in entropy is described by:
  1. with increase in temperature, the value of K for exothermic reaction decreases because the entropy change of the system is positive.
  2. with increase in temperature, the value of K for endothermic reaction increases because unfavourable change in entropy of the surroundings decreases.
  3. with increase in temperature, the value of K for exothermic reaction decreases because favourable change in entropy of the surroundings decreases.
  4. with increase in temperature, the value of K for endothermic reaction increases because the entropy change of the system is negative.

Solution

ΔSsurrounding=-qprocessTsurrounding

If ΔH>0, on increasing temperature, Kequilibrium also increase, so ΔSsurrounding<0 (Surrounding is unfavourable).

If ΔH<0, on increasing temperature Kequilibrium, decreases, so ΔSsurrounding>0 (Surrounding is favourable).

Asked in: JEE Advanced 2017 (Paper 2)

Practice more Thermodynamics (C) questions on Aicharya