Question

The rate constant, k, for a first-order reaction is equal to 4.3 × 10-4 s-1. What is the half-life for the reaction? The rate constant, k, for a first-order reaction is equal to 4.3 × 10-4 s-1. What is the half-life for the reaction? 1.9 × 103 s 1.2 × 103 s 1.6 × 103 s 3.0 × 10-4 s

Answer 1

Answer:

1.6 × 10³ s

Explanation:

Let's consider the following generic reaction.

A → B

The rate law is:

$rate=k \times [A]^{m}$

where,

rate is the reaction rate

k is the rate constant

[A] is the molar concentration of the reactant A

m is the reaction order

When m = 1, we have a first-order reaction. We can calculate the half-life for this reaction using the following expression.

$t_{1/2}=\frac{ln2}{k} =\frac{ln2}{4.3 \times 10^{-4}s^{-1} }=1.6 \times 10^{3}s$