$20 \, mL$ of $0.02 \, M$ hypo solution is used for the titration of $10 \, mL$ of copper sulphate solution,in the presence of excess of $KI$ using starch as an indicator. The molarity of $Cu^{2+}$ is found to be $\times 10^{-2} \, M$ [nearest integer]. Given: $2 Cu^{2+} + 4 I^{-} \rightarrow Cu_{2}I_{2} + I_{2}$ and $I_{2} + 2 S_{2}O_{3}^{2-} \rightarrow 2 I^{-} + S_{4}O_{6}^{2-}$.

In the volumetric analysis of $HCl$,if we use phenolphthalein as an indicator,which base is unsuitable for titration?

While titrating a dilute $HCl$ solution with an aqueous $NaOH$ solution,which of the following will not be required?

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

In a titration experiment,$10 \, mL$ of an $FeCl_{2}$ solution consumed $25 \, mL$ of a standard $K_{2}Cr_{2}O_{7}$ solution to reach the equivalence point. The standard $K_{2}Cr_{2}O_{7}$ solution is prepared by dissolving $1.225 \, g$ of $K_{2}Cr_{2}O_{7}$ in $250 \, mL$ water. The concentration of the $FeCl_{2}$ solution is closest to $..... \, N$
[Given : molecular weight of $K_{2}Cr_{2}O_{7} = 294 \, g \, mol^{-1}$]

Solution $X$ contains $Na_2CO_3$ and $NaHCO_3$. $20 \ mL$ of $X$ when titrated using methyl orange indicator consumed $60 \ mL$ of $0.1 \ M \ HCl$ solution. In another experiment,$20 \ mL$ of $X$ solution when titrated using phenolphthalein consumed $20 \ mL$ of $0.1 \ M \ HCl$ solution. The concentrations (in $mol \ L^{-1}$) of $Na_2CO_3$ and $NaHCO_3$ in $X$ are respectively: