$0.5$ molal aqueous solution of a weak acid $(HX)$ is $20\%$ ionised. If $K_f$ for water is $1.86\, K\, kg\, mol^{-1}$,the lowering in freezing point of the solution is $........ K$.

If $0.004 \ M \ Na_2SO_4$ and $0.01 \ M$ glucose aqueous solutions are isotonic,then the degree of dissociation of $Na_2SO_4$ is ........ $\%$.

$A$ $0.1 \ mol$ of a binary electrolyte undergoes complete dissociation in $250 \ g$ of a protic solvent. If the elevation in boiling point is $1.5 \ K$,the molal elevation constant $(K_b)$ is ............. $K \ kg \ mol^{-1}$.

Of the following four aqueous solutions,the total number of those solutions whose freezing point is lower than that of $0.10 \, M \, C_{2}H_{5}OH$ is (Integer answer).
$(i)$ $0.10 \, M \, Ba_{3}(PO_{4})_{2}$
$(ii)$ $0.10 \, M \, Na_{2}SO_{4}$
$(iii)$ $0.10 \, M \, KCl$
$(iv)$ $0.10 \, M \, Li_{3}PO_{4}$

Which of the following is a non-electrolyte?

Which one has the highest boiling point?