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 0.33 M?1.8 s1.3 s0.089 s5.6 s0.31 s

1.3 s

Explanation:

A first-order reaction can be represented through the following expression.

ln [A] = ln [A]₀ - k. t

where,

[A] is the concentration of the reactant A at a certain time t

k is the rate constant

When the concentration decreases to half its value ([A] = 0.5 [A]₀), the time elapsed is known as half-life t (1/2).

ln (0.5 [A]₀) = ln [A]₀ - k. t (1/2)

ln 0.5 = - k. t (1/2)

t (1/2) = - ln 0.5 / k = - ln 0.5 / (0.54 s⁻¹) = 1.3 s