Aparticular reactant decomposes with a half‑life of 109 s when its initial concentration is 0.280 m. the same reactant decomposes with a half‑life of 231 s when its initial concentration is 0.132 m.
1. determine the reaction order.
(a)1
(b)2
(c)0
2. what is the value and units of the rate constant for this reaction? =

The order of reaction is 2.

Rate constant is 0.0328 (M s)⁻¹

Explanation:

The rate of a reaction is inversely proportional to the time taken for the reaction.

As we are decreasing the concentration of the reactant the half life is increasing.

a) For zero order reaction: the half life is directly proportional to initial concentration of reactant

b) for first order reaction: the half life is independent of the initial concentration.

c) higher order reaction: The relation between half life and rate of reaction is:

Rate =

Half life =

where n = order of reaction

Putting values

Hence n = 2

Putting values

K = 0.0328