Question

The initial concentration of reactant (A) is 2 mol dm⁻³ for a zero order reaction \[\ce{A -> B}\]. The rate constant (k) is related to its half-life `("t"_(1//2))` by the equation:

Options

• k = `("t"_(1//2))^(-1)`

• k = `("t"_(1//2))^0`

• k = `("t"_(1//2))^(-2)`

• k = `sqrt("t"_(1//2))`

Answer 1

k = `("t"_(1//2))^(-1)`

Explanation:

For zero order reaction,

`("t")_(1//2) = (["A"]_0)/(2"k")`

∴ k = `(["A"]_0)/(2 xx "t"_(1//2))`

= `2/(2 xx "t"_(1//2))`

= `1/("t"_(1//2))`

= `("t"_(1//2))^(-1)`