Which of the following statement is correct about catalyst?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Same reactants may give different product by using different catalysts.
A catalyst is selective: it speeds up one particular reaction out of several possible ones, so the same reactants (for example CO and \( \ce{H2} \)) can give different products with different catalysts.
Why the other options are incorrect
Option (1) Catalyst is required in large quantities to catalyse reactions — Incorrect. A small amount of catalyst is enough, because it is regenerated and used again and again.
Option (3) Catalytic activity of catalyst does not depend upon the strength of chemisorption — Incorrect. Activity does depend on it; the reactants must be adsorbed reasonably strongly to become active, but not so strongly that they stay fixed on the surface.
Option (4) A catalyst does not remain the same before and after the reaction — Incorrect. A catalyst remains unchanged in mass and chemical composition at the end of the reaction.
NCERT (Pre-rationalised edition, 2022-23):
Important Features of Solid Catalysts
