Question

What is the role of catalyst in reaction?

• A. To increase activation energy of a reaction
• B. To decrease the equilibrium constant of the reaction
• C. To supply energy to the reactants
• D. To decrease activation energy of a reaction

Hint:

A catalyst opens an alternative path with a lower energy barrier.

Answer 1

The Correct Option is D

Step 1: Approach
Use the Arrhenius equation to see what a catalyst must change.

Step 2: Equation
\[ k = A e^{-E_a/RT} \]
Rate rises when $k$ rises. At the same temperature, $k$ can rise a lot only if $E_a$ becomes smaller.

Step 3: Conclusion
So a catalyst lowers the activation energy. It leaves the overall energy change and the equilibrium constant alone, and it does not add energy. Option (D) is the correct one.

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