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

How many g of ${\rm{KMn}}{{\rm{O}}_4}$ are needed to prepare 3.75 litre of 0.850 $N$ solution if ${\rm{KMn}}{{\rm{O}}_4}$ is reduced as, ${\rm{MnO}}_4^ - + 8{{\rm{H}}^ + } + 5{\rm{e}} o {\rm{M}}{{\rm{n}}^{2 + }} + 4{{\rm{H}}_2}{\rm{O}}$

What mass of ${\rm{Mn}}{{\rm{O}}_2}$ is reduced by 35 mL of 0.16 $N$ oxalic acid in acidic solution? The skeleton equation is, ${\rm{Mn}}{{\rm{O}}_2} + {{\rm{H}}^ + } + {{\rm{H}}_2}{{\rm{C}}_2}{{\rm{O}}_4} o {\rm{C}}{{\rm{O}}_2} + {{\rm{H}}_2}{\rm{O}} + {\rm{M}}{{\rm{n}}^{2 + }}:$

1 gram of sodium hydroxide is neutralized with excess hydrochloric acid. If 0.73 g of sodium chloride is formed, what is the percentage yield of the reaction?

What weight of ${\rm{HN}}{{\rm{O}}_3}$ is needed to convert 5 g of iodine into iodic acid according to the reaction, ${{\rm{I}}_2} + {\rm{HN}}{{\rm{O}}_3} o {\rm{HI}}{{\rm{O}}_3} + {\rm{N}}{{\rm{O}}_2} + {{\rm{H}}_2}{\rm{O}}?$ ?

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?

1 gram of sodium hydroxide was reacted with $25 \mathrm{mL}$ of $0.75 \mathrm{M}$ sulfuric acid ($\mathrm{H_2SO_4}$). What mass of sodium hydroxide remains unreacted?

$0.2$ 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 :

A metal M forms a volatile carbonyl complex $M(CO)_x$. 0.525g of this complex is heated in a closed vessel of volume 250 mL at $50^\circ C$. The pressure inside the vessel after complete decomposition of the complex is 746 Torr. If the gas constant R is 0.0821 L atm $K^{-1} mol^{-1}$, what is the value of x in the formula $M(CO)_x$? (Assume the metal M does not contribute significantly to the pressure)

1 gram of potassium hydroxide was treated with $20 \mathrm{mL}$ of $0.5 \mathrm{M}$ HCl solution. The mass of potassium hydroxide left unreacted is equal to

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 :