Question

The rate constant for a first-order reaction whose half-life is 480 seconds is ______.

Options

• 2.88 × 10⁻³ sec⁻¹

• 2.72 × 10⁻³ sec⁻¹

• 1.44 × 10⁻³ sec⁻¹

• 1.44 sec⁻¹

Answer 1

The rate constant for a first-order reaction whose half-life is 480 seconds is 1.44 × 10⁻³ sec⁻¹.

Explanation:

For a first-order reaction, k = `0.693/t_(1/2)`

Where k = rate constant

`t_(1/2)` = half-life period = 480 seconds

∴ k = `0.693/480`

= 1.44 × 10⁻³ sec⁻¹