JEE Main 2023 — Surface Chemistry Question with Solution

Let's analyze each statement about modern adsorption theory of heterogeneous catalysis:

A. The catalyst is diffused over the surface of reactants.

This statement is incorrect. In heterogeneous catalysis, the catalyst is usually a solid, and the reactants are in a different phase (gas or liquid). The reactants are adsorbed on the catalyst's surface, not the other way around.

B. Reactants are adsorbed on the surface of the catalyst.

This statement is correct. In the adsorption theory of heterogeneous catalysis, reactants are adsorbed onto the surface of the catalyst, where they undergo a chemical reaction.

C. Occurrence of chemical reaction on the catalyst's surface through formation of an intermediate.

This statement is correct. In the adsorption theory, the reaction takes place on the catalyst's surface through the formation of an intermediate species.

D. It is a combination of intermediate compound formation theory and the old adsorption theory.

This statement is correct. The modern adsorption theory of heterogeneous catalysis combines the concepts of intermediate compound formation and the old adsorption theory.

E. It explains the action of the catalyst as well as those of catalytic promoters and poisons.

The modern adsorption theory of heterogeneous catalysis does explain the action of the catalyst. However, the roles of catalytic promoters and poisons are not entirely explained by this theory. The NCERT textbook states that the modern adsorption theory explains the action of the catalyst but does not elaborate on the roles of promoters and poisons.

Therefore, considering the information provided by the NCERT textbook, point E is not entirely correct. There are three correct statements (B, C, and D) about the modern adsorption theory of heterogeneous catalysis.