The value of the rate constant of a pseudo-first-order reaction:

1. Depends on the concentration of reactants present in a small amount.
2. Depends on the concentration of reactants present in excess.
3. Is independent of the concentration of reactants.
4. Depends only on temperature.

Pseudo first-order reaction is a chemical reaction in which the rate of reaction depends upon the concentration of only one reactant while the concentration of another reactant has no effect on the rate of reaction.

The reaction is as follows:

\(\mathrm{CH}_{3} \mathrm{COOC}_{2} \mathrm{H}_{5}+\mathrm{H}_{2} \mathrm{O} \stackrel{\mathrm{H}^{+}}{\longrightarrow} \mathrm{CH}_{3} \mathrm{COOH}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\)

The rate law is as follows:

\(Rate = k[CH_{3}COOC_{2}H_{5}][H_{2}O]\)

The concentration of H2O is constant hence, \(k[H_{2}O]=k^{'}\)

Rate = k'\([CH_{3}COOC_{2}H_{5}]\)


Hence, the rate constant depends on the concentration of reactant present in excess