A standard HCl solution is titration to a pink phenolphtalein endpoint by adding NaOH solution while
Channel: Doubtnut
Date: 2020-04-19

A standard HCl solution is titration to a pink phenolphtalein endpoint by adding NaOH solution while stirring. If a solution becomes pink throughout but loses  its colour upon standing for a short time, what should be done to restore the coloure ?