Question

What is the rate constant for a first-order reaction if the initial concentration of the reactant is 1.5 M and its concentration after 2 minutes is 0.75 M? The half-life of the reaction is 4 minutes.

Answer 1

For a first-order reaction, the rate constant  k  can be calculated using the half-life  t1/2  with the following equation:k = 0.693 / t1/2Given that the half-life of the reaction is 4 minutes, we can calculate the rate constant as follows:k = 0.693 / 4k  0.173 minSo, the rate constant for this first-order reaction is approximately 0.173 min.