Question

How does a catalyst change during a reaction?

(a) Physically

(b) Mass-wise

(c) Chemically

(d) Quantitatively

The question was posed to me in an international level competition.

This question is from Surface Chemistry in chapter Surface Chemistry of Chemistry – Class 12

Answer 1

Right option is (a) Physically

To elaborate: Yes, a catalyst can be changed physically in a chemical reaction but by definition a catalyst is not consumed as a reactant. It must be regenerated back into its original form after the reaction has taken place. Its function is to lower the reaction potential allowing the reaction between reactants to take place.