$10 \, mL$ 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:

$A$ solution containing $Na_2CO_3$ and $NaOH$ requires $300 \ mL$ of $0.1 \ N$ $HCl$ using phenolphthalein as an indicator. Methyl orange is then added to the above titrated solution when a further $25 \ mL$ of $0.2 \ N$ $HCl$ is required. The amount of $NaOH$ present in the solution is ................. $g$ $(NaOH = 40, Na_2CO_3 = 106)$.

$25 \ mL$ of the given $HCl$ solution requires $30 \ mL$ of $0.1 \ M$ sodium carbonate solution. What is the volume of this $HCl$ solution required to titrate $30 \ mL$ of $0.2 \ M$ aqueous $NaOH$ solution? .............. $mL$

In the titration of $KMnO_{4}$ with $C_{2}O_{4}^{2-}$,which temperature range is not proper? Why?

$5.00 \ mL$ 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?

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

What is the indicator used in Argentometric titrations?