In the titration of $I_{2(aq)}$ by $S_2O_3^{2-}{_{\text{(aq)}}}$ using the starch indicator, the end point is indicated by:

$10 \, mL$ 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:

In the titration of potassium permanganate $(KMnO_4)$ against ferrous ammonium sulphate $(FAS)$ solution,dilute sulphuric acid $(H_2SO_4)$ but not nitric acid $(HNO_3)$ is used to maintain an acidic medium,because:

During the estimation of oxalic acid $Vs$ $KMnO_4$,the self-indicator is:

Temporary hardness in tap water is measured in terms of parts of $CaCO_3$ per $10^6$ parts of water. If $500 \ mL$ of hard water containing $Ca(HCO_3)_2$ was titrated against $\frac{1}{20} \ M \ H_2SO_4$ solution in the presence of a methyl orange indicator,and it required $40 \ mL$ of titrant,then the temporary hardness in the tap water is .............. $ppm$.

$50 \ cm^{3}$ 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 $cm^{3}$)