Question

Assertion (A): In a first order reaction, if the concentration of the reactant is doubled, its half-life is also doubled.
Reason (R): The half-life of a reaction does not depend upon the initial concentration of the reactant in a first order reaction.

• (A) and (R) are true, and (R) is the correct explanation of (A).
• (A) and (R) are true, but (R) is not the correct explanation of (A).
• (A) is true, but (R) is false.
• (A) is false, but (R) is true.

Hint:

In first-order reactions, half-life is constant and does not depend on the initial concentration.

Answer 1

The Correct Option is C

In a first-order reaction, the half-life is independent of the initial concentration of the reactant, meaning that doubling the concentration does not change the half-life. Therefore, Assertion (A) is true as it correctly explains the effect on half-life, but Reason (R) is false because it incorrectly states that the half-life does not depend on the concentration.