Question

Application of adsorption is/are:
(A) For desiccation or dehumidification
(B) Heterogeneous catalysts
(C) For both heterogeneous catalysts and for desiccation or dehumidation
(D) None of the above

Answer 1

Hint: 1. It is used to reduce humidity levels, making your home less hospitable to allergens such as dust, mites and mold.
2. Ammonia is manufactured from hydrogen and nitrogen in Hber’s process. Finely divided iron catalyst is used.

Complete step by step answer:
What is Adsorption?
It is a process which involves the accumulation of a substance in molecular species in higher concentration on the surface. Adsorption is a surface phenomenon. Solids that are used to adsorb gases or dissolved substances adsorbents the adsorbed molecules are usually referred as the adsorbate. The process of removal of adsorbent from the surface of adsorbate is known as desorption. Adsorption is caused by London Dispersion Forces, a type of Van der Waals force which exists between molecules.
Adsorption is of two types:
1) Physically adsorption: It is also called physisorption. It is due to weak Van der Waals forces between adsorbate and adsorbent. It enables one to characterize a solid’s texture by determining its surface area, porosity and total pore volume.
2) Chemical adsorption: It is also called chemisorption. It is due to strong chemical forces of bonding type between adsorbate and adsorbent. Amount of heat liberated when a unit mass of gas is adsorbed on the surface is called heat of adsorption.
Applications of Adsorption are:
1- For desiccation or dehumidation: These substances can be used to reduce or remove water vapour or moisture present in the air. Example, Silica gel and alumina are used for dehumidification in electronic equipment.
2- Heterogeneous catalyst: These reactions proceed through the adsorption of gaseous reactants on solid catalysts. Example, Finely powdered nickel is used for hydrogenation of oils.
Therefore, option C is the answer.

Note: Heterogeneous catalysis is very important because it enables faster, large-scale production and the selective product formation. The production of 90% of chemicals is assisted by solid catalysts. The chemical and energy industries rely heavily on heterogeneous catalysis.