Question

When initial concentration of the reactant is doubled, the half-life period of a zero-order reaction ______.

Options

• is tripled

• is doubled

• is halved

• remains unchanged

Answer 1

When initial concentration of the reactant is doubled, the half-life period of a zero-order reaction is doubled.

Explanation:

For a zero-order reaction, the half-life is directly proportional to the initial concentration of the reactant.

The half-life of the zero-order reaction is given as:

`t_(1//2) = [R]_0/(2 k)`

Where:

[R]₀ = initial concentration

k = rate constant

So, when [R]₀ is doubled:

`t_(1//2)^' = (2 [R]_0)/(2 k)`

`t_(1//2)^' = [R]_0/k`

= `2 xx [R]_0/(2 k)`

= 2 t_1/2