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. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
• B. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
• C. Assertion (A) is true, but Reason (R) is false.
• D. Assertion (A) is false, but Reason (R) is true.

Hint:

In first-order reactions, the half-life is unaffected by the concentration of reactants, which is a distinctive characteristic of these reactions.

Answer 1

The Correct Option is D

In the case of a first-order reaction, the half-life is constant and does not depend on the initial concentration of the reactant. This means the half-life remains the same, regardless of any changes in the concentration of the reactant over time. Therefore, Assertion (A) is incorrect, while Reason (R) is correct. \bigskip Step 2: Thus, Assertion (A) is false, and Reason (R) is true. \bigskip