The value of rate constant of a pseudo first order reaction

A Higher order reaction converted into lower order by taking one of the reactant in large excess is called as pseudo order reaction.consider reaction  A+2B→productsrate=kAB2B is taken in large it does not influence rate of reaction KB2 is constant.rate=k'A,where K'=kB2 3rd order is converted into 1st order and rate constant depends on B taken in large excess.