Hello !

'Pseudo' means 'fake'. So pseudo first order reaction is the reactions which is actually 2nd order reaction or biomolecular reaction in reality but the reaction is made to behave like 1st order reaction if one substance is in excess amount or the concentration is taken as contant for one substance.

Hello!

A Pseudo first order reaction can be defined as a second order or bimolecular reaction that is made to behave like a first order reaction. This reaction occurs when one reacting material is present in great excess or is maintained at a constant concentration compared with the other substance.

For example, a second – order of the reaction is given by the equation,

A + B —-> C + D

This reaction is dependent upon the concentrations of both A and B but one of the components is present in large excess and thus its concentration hardly changes as the reaction proceeds.

So, if component B is in large excess and the concentration of B is very high as compared to that of A, the reaction is considered to be pseudo-first order reaction with respect to A and if component A is in large excess and the concentration of A is very high as compared to that of B,