The rate constant for a first-order reaction is 0.54 s-1. What is the half-life of this reaction if the initial concentration is 0.54 M? The rate constant for a first-order reaction is 0.54 s-1. What is the half-life of this reaction if the initial concentration is 0.54 M? 4.7 s 0.49 s 1.0 s 1.3 s 1.8 s