Which of the following methods is NOT suitable for concentrating a protein solution?

What volume of 0.40 $M$ ${\rm{N}}{{\rm{a}}_2}{{\rm{S}}_2}{{\rm{O}}_3}$ would be required to react with the ${{\rm{I}}_2}$ liberated by adding excess of KI to 50 mL of 0.20 $M$ ${\rm{CuS}}{{\rm{O}}_4}$ solution?

The number of moles of $KMn{O_4}$ that will be needed to react completely with one mole of oxalate ion in acidic solution is

What volume of 0.40 $M$ ${\rm{N}}{{\rm{a}}_2}{{\rm{S}}_2}{{\rm{O}}_3}$ would be required to react with the ${{\rm{I}}_2}$ liberated by adding excess of KI to 50 mL of 0.20 $M$ ${\rm{CuS}}{{\rm{O}}_4}$ solution?

$0.2$ g of a sample of ${{\rm{H}}_2}{{\rm{O}}_2}$ required $10$ mL of $N{\rm{KMn}}{{\rm{O}}_4}$ in a titration in the presence of ${{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}{\rm{.}}$. Purity of ${{\rm{H}}_2}{{\rm{O}}_2}$ is :

When one mole of ${\rm{KMn}}{{\rm{O}}_4}$ reacts with $HCl$, the volume of chlorine liberated at $NTP$ will be:

In the reaction, ${\rm{VO}} + {\rm{F}}{{\rm{e}}_2}{{\rm{O}}_3} o {\rm{FeO}} + {{\rm{V}}_2}{{\rm{O}}_5}{\rm{.}}$. The eq.wt. of ${{\rm{V}}_2}{{\rm{O}}_5}$ is equal to its :

$0.2$ g of a sample of ${{\rm{H}}_2}{{\rm{O}}_2}$ required $10$ mL of $N{\rm{KMn}}{{\rm{O}}_4}$ in a titration in the presence of ${{\rm{H}}_2}{\rm{S}}{{\rm{O}}_4}{\rm{.}}$. Purity of ${{\rm{H}}_2}{{\rm{O}}_2}$ is :

Weight of ${\rm{FeS}}{{\rm{O}}_4}\left( {{\rm{mol}}{\rm{.wt}}{\rm{.}} = 152} \right)$ oxidized by 200 mL of 1 $N$ ${\rm{KMn}}{{\rm{O}}_4}$ solution is :

In the following change, $3{\rm{Fe}} + 4{{\rm{H}}_2}{\rm{O}} o {\rm{F}}{{\rm{e}}_3}{{\rm{O}}_4} + 4{{\rm{H}}_2}$. If the atomic weight of iron is 56, then its equivalent weight will be :

What is the normality of a ${\rm{KMn}}{{\rm{O}}_4}$ solution to be used as an oxidant in acid medium, which contain 15.8 g of the compound in 100 mL of solution? Mol. wt. of ${\rm{KMn}}{{\rm{O}}_4}$ is 158 :