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?

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

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

100g of a liquid A (molar mass 140 g/mol) and 100g of liquid B (molar mass 70 g/mol) form an ideal solution. What is the mole fraction of B in the vapor phase? (Assume $P^0_A = 70$ mmHg and $P^0_B = 140$ mmHg)

If 1 kg of solvent contains 2 moles of solute, what is the molality of the solution?

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 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, ${\rm{Mn}}{{\rm{O}}_2} + {{\rm{H}}^ + } + {{\rm{H}}_2}{{\rm{C}}_2}{{\rm{O}}_4} o {\rm{C}}{{\rm{O}}_2} + {{\rm{H}}_2}{\rm{O}} + {\rm{M}}{{\rm{n}}^{2 + }}:$

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

In the standardization of ${\rm{N}}{{\rm{a}}_2}{{\rm{S}}_2}{{\rm{O}}_3}$ using ${{\rm{K}}_2}{\rm{C}}{{\rm{r}}_2}{{\rm{O}}_7}$ by iodometry, the equivalent weight of ${{\rm{K}}_2}{\rm{C}}{{\rm{r}}_2}{{\rm{O}}_7}$ is :

Which method is best suited for separating a mixture of two immiscible liquids with different densities?

For the reaction, $2{\rm{F}}{{\rm{e}}^{3 + }} + {\rm{S}}{{\rm{n}}^{2 + }} o 2{\rm{F}}{{\rm{e}}^{2 + }} + {\rm{S}}{{\rm{n}}^{4 + }}$ The normality of ${\rm{SnC}}{{\rm{l}}_2}$ (mol.wt. = 189.7) solution prepared by dissolving 47.5 g in acid solution and diluting with ${{\rm{H}}_2}{\rm{O}}$ to a total of 2.25 litre is :