The rate constant,k,for a first-order reaction is equal to 4.2 × 10^-4 s^-1.What is the half-life for the reaction?

Question

Quizplus · Accepted Answer

The half-life of a first-order reaction can be calculated using the equation t1/2 = 0.693/k. Substituting the value of k given in the problem, we get t1/2 = 0.693/4.2 × 10^-14 s^-1 = 1.7 × 10^-13 s = 1.7 × 10^-11 s (in scientific notation with 2 significant figures). Therefore, the best choice is C.

The Rate Constant,k,for a First-Order Reaction Is Equal to 4