Which of the following $0.1 \ m$ aqueous solutions exhibits the highest osmotic pressure at $25^{\circ}C$?

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

The elevation of boiling point of $0.10 \ m$ aqueous $CrCl_{3} \cdot xNH_{3}$ solution is two times that of $0.05 \ m$ aqueous $CaCl_{2}$ solution. The value of $x$ is.........
[Assume $100 \%$ ionisation of the complex and $CaCl_{2},$ coordination number of $Cr$ as $6,$ and that all $NH_{3}$ molecules are present inside the coordination sphere $]$

Calculate the depression in the freezing point of water when $10 \ g$ of $CH_3CH_2CHClCOOH$ is added to $250 \ g$ of water. $K_a = 1.4 \times 10^{-3}$,$K_f = 1.86 \ K \ kg \ mol^{-1}$

The boiling point of $0.001 \ M$ aqueous solutions of $NaCl$,$Na_{2}SO_{4}$,$K_{3}PO_{4}$ and $CH_{3}COOH$ should follow the order.

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