Question

The value of rate constant of a pseudo first order reaction ____________.
(i) depends on the concentration of reactants present in small amount.
(ii) depends on the concentration of reactants present in excess.
(iii) is independent of the concentration of reactants.
(iv) depends only on temperature.


NCERT Class XII
Chemistry - Exemplar Problems

Chapter 4. Chemical Kinetics

Answer 1

The answer is : (ii)...................

Answer 2

The ‘value of rate constant’ of a ‘pseudo first reaction’ which is independent on the concentration of any of the reactant. So, the correct option is (iii).

A ‘pseudo first order reaction’ is the reaction in which the molecularity of reaction is two whereas the ‘order of reaction’ is one.

This is because one of the reactant is in excess here so that it will not affect the ‘rate of reaction’ but since it is a reactant so it is part of molecularity. Hence for a ‘pseudo first order reaction’ the rate of reaction depends on the concentration of reactant present in limited amount.