$A$ compound contains $1.08 \ mol$ of $Na, 0.539 \ mol$ of $Cu$ and $2.16 \ mol$ of $F$. Its aqueous solution shows osmotic pressure which is three times that of urea having the same molar concentration. The formula of the compound is:

An aqueous solution is prepared by dissolving $0.1 \ mol$ of an ionic salt in $1.8 \ kg$ of water at $35^{\circ} C$. The salt remains $90 \%$ dissociated in the solution. The vapour pressure of the solution is $59.724 \ mm \ Hg$. Vapor pressure of water at $35^{\circ} C$ is $60.000 \ mm \ Hg$. The number of ions present per formula unit of the ionic salt is . . . . . .

$1$ molal aqueous solution of an electrolyte $A_{2}B_{3}$ is $60\%$ ionised. The boiling point of the solution at $1 \ atm$ is ......... $K$.
(Rounded-off to the nearest integer)
[Given $K_{b}$ for $H_{2}O = 0.52 \ K \ kg \ mol^{-1}$]

The freezing point of a $0.0020 \ m$ aqueous solution of $[CO(NH_3)_5(NO_2)]$ is $-0.00732 \ ^oC$. The number of ions produced (van't Hoff factor,$i$) when $1 \ mol$ of this ionic compound is dissolved in water is ..... $(K_f = 1.86 \ K \ kg \ mol^{-1})$

$A$ $0.5 \ m$ aqueous solution of a weak acid $(HX)$ is $20\%$ ionized. If $K_f$ for the solvent is $1.86 \ K \ kg \ mol^{-1}$,the depression in freezing point of the solution is ..... $K$.

Which of the following aqueous solutions will have the highest freezing point?