Question

The half life period for catalytic decomposition of AB3 at 50 mm is found to be 4 hrs and at 100 mm it in 2 hrs. The order of reaction is :

A. 2
B. 1
C. 2
D. 0

Answer 1

The order of the chemical reaction for catalytic decomposition of AB3 is zero-order, as the half-life period changes inversely with the concentration of the reactant.

Step-by-step explanation:

The question pertains to the order of a chemical reaction based on the half-life periods at different reactant concentrations. The given data states that the half-life period for the decomposition of AB3 is 4 hours at a concentration of 50 mm and 2 hours at 100 mm. To determine the order of the reaction, one needs to look at the dependence of the half-life on concentration.

In a first-order reaction, the half-life is independent of initial concentrations. However, the provided data shows that the half-life changes with concentration, indicating that the reaction is not first order. For a zero-order reaction, the half-life is directly proportional to the initial concentration. Thus, as the concentration of AB3 doubles, the half-life is halved, which is consistent with the characteristics of a zero-order reaction.

In conclusion, the decomposition reaction of AB3 is a zero-order reaction because the half-life varies inversely with the concentration of the reactant.