What is a pseudo first order reaction?

Answer 1

A and B react to produce P:



If the initial concentration of the reactant A is much larger than the concentration of B, the concentration of A will not change appreciably during the course of the reaction The concentration of the reactant in excess will remain almost constant. Thus the rate's dependence on B can be isolated and the rate law can be written as

v=-d[B]/dt = k' x [B], where k' = k x [A]

Answer 2

A pseudo first order reaction has two critical steps which approximate a first order process.