$50 \ cm^{3}$ of $0.2 \ N \ HCl$ is titrated against $0.1 \ N \ NaOH$ solution. The titration was discontinued after adding $50 \ cm^{3}$ of $NaOH$. The remaining titration is completed by adding $0.5 \ N \ KOH$. The volume of $KOH$ required for completing the titration is (in $cm^{3}$)

$10 \, mL$ of concentrated $HCl$ is diluted to $1 \, L$. If $20 \, mL$ of this diluted solution is completely neutralized by $25 \, mL$ of $0.1 \, N$ sodium hydroxide solution,then the normality of the original concentrated hydrochloric acid is:

Which of the following statements is correct?

Why in the redox titration of $KMnO_4$ vs oxalic acid,do we heat the oxalic acid solution before starting the titration?

$5.00 \ mL$ of $0.10 \ M$ oxalic acid solution taken in a conical flask is titrated against $NaOH$ from a burette using phenolphthalein indicator. The volume of $NaOH$ required for the appearance of permanent faint pink color is tabulated below for five experiments. What is the concentration,in molarity,of the $NaOH$ solution?

$Exp. \ No.$	$Vol. \ of \ NaOH \ (mL)$
$1$	$12.5$
$2$	$10.5$
$3$	$9.0$
$4$	$9.0$
$5$	$9.0$

The indicator used during the estimation of $COD$ of a water sample is