Question

Powdered substances are more effective adsorbents than their crystalline form because:

• A. adsorption is an exothermic process
• B. they become inert and do not react with the absorbate
• C. the extent of adsorption increases with increase in surface area of the adsorbent
• D. adsorption is more if the size of adsorbent is small

Answer 1

The correct option is C the extent of adsorption increases with increase in surface area of the adsorbent

Two types of substance are involved in adsorption,
1. Adsorbent
2. Adsorbate

The molecular species or substance, which concentrates or accumulates at the surface is called adsorbate.

The material on the surface of which the adsorption takes place is called adsorbent.

Adsorption is a surface phenomenon.
So, Solids, particularly in finely divided state have large surface area and act as good adsorbents. Thus, the adsorption will be more.

Hence, powdered substance are more effective adsorbents than crystalline forms due to their large surface area.