Question

Which of the following statements is true with respect to the extent of physisorption?

(a) Increases with increase in temperature

(b) Decreases with increase in surface area

(c) Decreases with increase in the strength of Van der Waals forces

(d) Decreases with increase in temperature

This question was posed to me during an internship interview.

I'd like to ask this question from Surface Chemistry in portion Surface Chemistry of Chemistry – Class 12

Answer 1

Right choice is (d) Decreases with increase in temperature

To elaborate: Physisorption is an exothermic process. According to Le-Chatelier’s principle, an exothermic reaction is favoured by a decrease in temperature. Therefore, the extent of physisorption decreases on increasing temperature.