Question

What is the role of catalyst in catalytic reaction ?

• A. It decreases the enthalpy of reaction.
• B. It increases the enthalpy of reaction.
• C. It decreases the energy of activation of reaction.
• D. It increases the energy of activation of reaction.

Hint:

A catalyst provides an alternate path with lower activation energy.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
Activation energy is the minimum energy colliding molecules need to react. A catalyst changes the pathway, not the start and end states.

Step 2: Detailed Explanation
A catalyst offers a different route with a lower activation energy barrier. More molecules can cross it, so the rate increases.
The enthalpy of reaction depends only on reactants and products, so a catalyst does not change it. Hence (A) and (B) are wrong. Raising the activation energy (D) would slow the reaction, the opposite of catalysis.

Final Answer:
A catalyst decreases the activation energy, option (C). \[ \boxed{\text{Decreases activation energy}} \]