In general, to calculate the rate constant for a first order decomposition reaction, A $\rarr$ products, given the time needed to decrease the initial concentration by one half, which equation should be used

Question

In general, to calculate the rate constant for a first order decomposition reaction, A $\rarr$  products, given the time needed to decrease the initial concentration by one half, which equation should be used

Quizplus · Accepted Answer

The correct equation for a first order decomposition reaction is ln([A]t/[A]0)=-kt, where [A]t is the concentration of A at time t, [A]0 is the initial concentration of A, and k is the rate constant. When the initial concentration decreases by one half, [A]t/[A]0 becomes 1/2, and substituting this into the equation gives ln(1/2)=-kt. Solving for k gives k=ln(2)/t1/2, where t1/2 is the time needed to decrease the initial concentration by one half. Therefore, choice B is the correct equation to use for calculating the rate constant for a first order decomposition reaction.

In General, to Calculate the Rate Constant for a First →\rarr→

In General, to Calculate the Rate Constant for a First $\rarr$