For a first-order reaction, the rate constant (k) is related to half-life (t1/2) as
Q1. For a first-order reaction, the rate constant (k) is related to half-life (t1/2) as
Answer: k = 0.693 / t1/2
Explanation: For a first-order reaction, t1/2 = 0.693 / k. Rearranging gives k = 0.693 / t1/2, using the formula for half-life of first-order reactions.