Question

What is the rate law of hydrolysis of CH3COOC2H5 in aqueous solution?

(a) R=k [CH3COOC2H5]^2

(b) R=k [CH3COOC2H5]

(c) R=k [CH3COOC2H5] [H2O]

(d) R=kk’ [CH3COOC2H5][H2O]

This question was posed to me in an interview.

This interesting question is from Chemical Kinetics in section Chemical Kinetics of Chemistry – Class 12

Answer 1

Correct option is (b) R=k [CH3COOC2H5]

The explanation: The reaction involved in acid hydrolysis of ester = CH3COOC2H5 + H2O → CH3COOH + C2H5OH. So the rate law becomes R=k’ [CH3COOC2H5][H2O], since water is present in large excess it is assumed to be constant throughout the reaction.

R=k[CH3COOC2H5], where k is k’ [H2O].