The freezing point of one molal $NaCl$ solution,assuming $NaCl$ to be $100\%$ dissociated in water,is ............ $^oC$. (molal depression constant $= 1.86$)

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 . . . . . .

Which of the following equimolar aqueous solutions has the highest freezing point?

$17.4\% \text{ (mass/volume) } K_2SO_4$ solution at $27^\circ C$ is isotonic to $5.85\% \text{ (mass/volume) } NaCl$ solution at $27^\circ C$. If $NaCl$ is $100\%$ ionized,what is the $\%$ ionization of $K_2SO_4$ in aqueous solution? [Atomic weights: $K = 39, Na = 23, S = 32, O = 16, Cl = 35.5$]

$80$ mole percent of $MgCl_2$ is dissociated in aqueous solution. The vapour pressure of $1.0$ molal aqueous solution of $MgCl_2$ at $38^{\circ} C$ is $.........$ $mm$ $Hg$. (Nearest integer)
Given : Vapour pressure of water at $38^{\circ} C$ is $50$ $mm$ $Hg$.

Carnallite in solution in $H_2O$,shows the properties of