Which of the following solutions has the lowest freezing point?

$A$ sample of water is found to contain $5.85 \% \left(\frac{w}{w}\right)$ of $AB$ (molecular mass $58.5$) and $9.50 \% \left(\frac{w}{w}\right)$ $XY_2$ (molecular mass $95$). Assuming $80 \%$ ionisation of $AB$ and $60 \%$ ionisation of $XY_2$, the freezing point of the water sample is: [Given, $K_f$ for water $= 1.86 \ K \ kg \ mol^{-1}$, freezing point of pure water $= 273 \ K$ and $A, B, X, Y$ are monovalent ions.] (in $K$)

If the degree of ionisation of $KI_3$ is $80\%$,then what will be its van't Hoff factor?

When mercuric iodide $(HgI_2)$ is added to an aqueous solution of potassium iodide $(KI)$,the

The freezing points of equimolar solutions of glucose,$KNO_3$ and $AlCl_3$ are in the order of:

If the relative decrease in vapour pressure is $0.4$ for a solution containing $1 \, mol$ of $NaCl$ in $3 \, mol$ of $H_2O$,the degree of ionization of $NaCl$ is .......... $\%$.