Question

Adsorption is accompanied by the evolution of heat. So according to Le-Chatelier principle, the amount of substance adsorbed should :

• A. increase with decrease in temperature
• B. increase with increase in temperature
• C. decrease with decrease in temperature
• D. decrease with increase in temperature

Answer 1

The correct option is A increase with decrease in temperature

• Adsorption is an exothermic process. So, heat gets evolved after adsorption.
• We can say by Le-Chatelier's principle that more of gas is adsorbed when pressure is increased as the volume of the gas decreases and since the adsorption process is exothermic, the adsorption occurs readily at low temperature and decreases with increasing temperature.
  
• So the correct case is it increases with a decrease in temperature.