Question

Assertion : For a first order reaction, $t_{1/2}$ is independent of rate constant.
Reason: For a first order reaction, $t_{1 /2} \propto\left[R\right]_{0}$.

• A. If both assertion and reason are true and reason is the correct explanation of assertion.
• B. If both assertion and reason are true but reason is not the correct explanation of assertion.
• C. If assertion is true but reason is false
• D. If both assertion and reason are false.

Answer 1

Answer: (D)

For a first order reaction half-life period is constant i.e. it is independent of initial concentration of the reacting species. It is related to rate constant as $t_{1 /2} =\frac{0.693}{k}$.