COMEDK2022ChemistrySurface Chemistry
The correct condition for physical adsorption is
Options
- AHigh T and high p
- BHigh T and low p
- CLow T and high p
- DT and p do not affect
Correct answer
C. Low T and high p
Step-by-step solution
Physical adsorption is an exothermic process, which can be represented by the equilibrium: Adsorbate + Adsorbent Adsorbed state + Heat. According to Le Chatelier principle, for an exothermic process, a decrease in temperature favors the forward reaction, leading to increased adsorption. Furthermore, increasing the pressure of the gas increases the concentration of gas molecules on the surface of the adsorbent, which also promotes physical adsorption. Therefore, physical adsorption is favored by low temperature and