$1 \ mol$ each of the following compounds is dissolved in $1 \ L$ of solution. Which will have the largest $\Delta T_b$ value?

$5 \ g$ of $Na_2SO_4$ was dissolved in $x \ g$ of $H_2O$. The change in freezing point was found to be $3.82 \ ^oC$. If $Na_2SO_4$ is $81.5 \%$ ionised,the value of $x$ ($K_f$ for water $= 1.86 \ ^oC \ kg \ mol^{-1}$) is approximately .............. $g$ (molar mass of $S = 32 \ g \ mol^{-1}$ and that of $Na = 23 \ g \ mol^{-1}$)

Calculate the amount of $KCl$ $(MW=74.5 \ g \ mol^{-1})$ required to depress the freezing point of $500 \ g$ of water by $2 \ K$ (in $g$)? $(K_f=1.86 \ K \ kg \ mol^{-1})$

For a dilute aqueous solution of glucose,the van't Hoff factor $(i)$ is:

Among the given solutions,which one has the highest boiling point under similar conditions?

At a certain temperature,the vapour pressure of pure water is $76 \ mm$ of $Hg$. When $1 \ mol$ of $Na_2SO_4$ is dissolved in $36 \ mL$ of water,the vapour pressure of the solution becomes $38 \ mm$ of $Hg$. What is the percentage dissociation of $Na_2SO_4$ in the solution?