Question

The rate constant for a first order reaction is 7.0 × 10^-4 s^-1. If initial concentration of reactant is 0.080 M, what is the half-life of reaction?

Options

• 990 s

• 79.2 s

• 12375 s

• 10.10 × 10^-4s

Answer 1

990 s

Explanation:

Given, k = 7 × 10^-4 s^-1, [A]₀ = 0.08 M

t_1/2 = `0.693/k = 0.0693/(7 xx 10^-4 " s")` = 990 s