Question

Physical adsorption is appreciable at ............. temperature.

• A. low
• B. high
• C. very high
• D. moderate

Answer 1

The correct option is A low

Physical adsorption is appreciable at low temperature.
In physical adsorption, equilibrium is established between the adsorbate and the fluid phase. In solid or gas systems, at not too high pressures, the extent of physical adsorption increases with increase in gas pressure and usually decreases with increasing temperature. Since physical adsorption is an exothermic process, the rate of physical adsorption is inversely proportional to temperature.