If the freezing point of an aqueous solution of salt $MX_4$ $(\alpha = 90\%)$ is $-3\ ^oC$,then its boiling point will be ........ $^oC$. (Assume it is $100\%$ ionized at the boiling temperature and $k_f = 1.86\ K\ kg\ mol^{-1}$,$k_b = 0.52\ K\ kg\ mol^{-1}$)

The vapour pressure of a non-ideal two-component solution is given below. Identify the correct $B.P.-x$ curve for the same mixture.

In the depression of freezing point experiment:
$A.$ Vapour pressure of the solution is less than that of pure solvent
$B.$ Vapour pressure of the solution is more than that of pure solvent
$C.$ Only solute molecules solidify at the freezing point
$D.$ Only solvent molecules solidify at the freezing point

For a solution formed by mixing liquids $L$ and $M$,the vapour pressure of $L$ plotted against the mole fraction of $M$ in solution is shown in the following figure. Here $x_L$ and $x_M$ represent mole fractions of $L$ and $M$,respectively,in the solution. The correct statement$(s)$ applicable to this system is(are)
$A$. Attractive intermolecular interactions between $L-L$ in pure liquid $L$ and $M-M$ in pure liquid $M$ are stronger than those between $L-M$ when mixed in solution
$B$. The point $Z$ represents vapour pressure of pure liquid $M$ and Raoult's law is obeyed when $x_L \rightarrow 0$
$C$. The point $Z$ represents vapour pressure of pure liquid $L$ and Raoult's law is obeyed when $x_L \rightarrow 1$
$D$. The point $Z$ represents vapour pressure of pure liquid $M$ and Raoult's law is obeyed from $x_L=0$ to $x_L=1$

An aqueous solution of urea (molar mass $= 60 \ g \ mol^{-1}$) boils at $100.18^o C$ at atmospheric pressure. If $K_f = 1.86 \ K \ kg \ mol^{-1}$ and $K_b = 0.512 \ K \ kg \ mol^{-1}$ for water,then the freezing point of the solution is equal to ..... $^o C$.

Benzene and toluene form an ideal solution over the entire range of composition. The vapour pressure of pure benzene and toluene at $300 \, K$ are $50.71 \, mm \, Hg$ and $32.06 \, mm \, Hg$ respectively. Calculate the mole fraction of benzene in the vapour phase if $80 \, g$ of benzene is mixed with $100 \, g$ of toluene.