When $\mathrm{CH}_3 \mathrm{COOCH}_3+\mathrm{HCl}$ is titrated with $\mathrm{NaOH}$ then at neutral point…
When $\mathrm{CH}_3 \mathrm{COOCH}_3+\mathrm{HCl}$ is titrated with $\mathrm{NaOH}$ then at neutral point the colour of phenolphthalein becomes colourless from pink due to
formation of $\mathrm{CH}_3 \mathrm{OH}$
formation of $\mathrm{CH}_3 \mathrm{COOH}$ which acts as a weak acid
phenolphthalein vaporizes
presence of $\mathrm{HCl}$.
Solution
$\mathrm{NaOH}$ solution is taken in a conical flask with phenolphthalein indicator (pink colour) and $\mathrm{CH}_3 \mathrm{COOCH}_3+\mathrm{HCl}$ solution is added from burette slowly.
First, $\mathrm{HCl}$ left after hydrolysis of ester (being a strong acid) gets consumed then $\mathrm{CH}_3 \mathrm{COOH}$ being a weak acid will bring the titration to the neutralisation point.
$\begin{aligned} & \mathrm{CH}_3 \mathrm{COOCH}_3 \frac{\mathrm{H}_2 \mathrm{O}}{\mathrm{H}^{+}} \rightarrow \mathrm{CH}_3 \mathrm{COOH}+\mathrm{CH}_3 \mathrm{OH} \\ & \mathrm{HCl}+\mathrm{NaOH} \longrightarrow \mathrm{NaCl}+\mathrm{H}_2 \mathrm{O} \\ & \mathrm{CH}_3 \mathrm{COOH}+\mathrm{NaOH} \longrightarrow \mathrm{CH}_3 \mathrm{COONa}\end{aligned}$