The number of moles of ${K_2}C{r_2}{O_7}$ that will be needed to react with one mole of nitrite ion in acidic solution is

A 0.5 molal aqueous solution of urea ($CON_2H_4$) is prepared. What is the mole fraction of urea?

100 mL of 0.1 M solution of a reductant is diluted to 1 litre, which of the following changes?

$0.2$ 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 :

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 :

In a solution containing 0.1 moles of a solute and 5 moles of solvent, what is the mole fraction of the solvent?

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 :

How many moles of solute are present in a 2 molal solution containing 250g of solvent?

A standard solution is one whose :

In the leaching of alumina from bauxite, the concentration of the ore is achieved by:

A colloidal solution of gold nanoparticles is prepared by reduction of $HAuCl_4$. Which of the following methods is MOST EFFECTIVE for purifying this solution from excess reactants and small ionic byproducts?