Question

With the help of an example explain what is meant by pseudo first order reaction.

Answer 1

Pseudo-first-order reaction: The reaction which is bimolecular but order is one is called a pseudo-first order reaction. This happens when one of the reactants is in large excess. E.g., acidic hydrolysis of the ester (ethyl acetate). 

CH₃COOC₂H₅ +H₂O ------>  CH₃COOH + C₂H₅OH 

similarly inversion of cane sugar or hydrolysis of cane sugar is an example of pseudo first-order reaction.