Question

Which of the following statements regarding catalyst are true?

• A. A catalyst remains unchanged in composition and quantity at the end of the reaction.
• B. A catalyst can initiate a reaction.
• C. A catalyst can alter the reaction rate in both direction.
• D. Catalysts are sometimes very specific in respect of reaction.

Answer 1

Answer: (A), (C), (D)

The correct options are
A A catalyst remains unchanged in composition and quantity at the end of the reaction.
C A catalyst can alter the reaction rate in both direction.
D Catalysts are sometimes very specific in respect of reaction.

Catalyst is a substance that increases the rate of a reaction without itself being consumed. Enzymes are naturally occurring catalysts responsible for many essential biochemical reactions.
The most important properties of catalysts are:
1. It alters the speed of a reaction, and it also affects the yield of the reaction product.
2. It actually takes part in the reaction even though it itself is not consumed or used up in the course of the reaction.
3. It provides an alternative pathway with a lower activation energy.
4. It is reaction-specific. It may not be effective in another reaction even if the two reactions are of similar type.

5. In a reversible reaction, a catalyst accelerates both the forward and the reverse reactions. So, the inclusion of a catalyst does not alter the equilibrium constant of a reversible reaction.

6. A catalyst can accelerate the rate of reaction but it can't initiate the reaction.

Therefore option A,C,D are correct