In countries nearer to the polar region,the roads are sprinkled with $CaCl_{2}$. This is

$x$ moles of $CO(NH_2)_2$ are present in $1200 \ g$ of water. If the freezing point of the solution is $-4.02 \ ^oC$,calculate the value of $x$. Given $k_f \ (H_2O) = 1.86 \ K \ kg \ mol^{-1}$.

$1.95 \ g$ of non-volatile and non-electrolyte solute dissolved in $100 \ g$ of benzene lowered the freezing point of it by $0.64 \ K$. The molar mass of the solute (in $g \ mol^{-1}$) is: $(K_{f}(C_6H_6) = 5.12 \ K \ kg \ mol^{-1})$

Which aqueous solution has the lowest freezing point?

Calculate the molar mass of the solute when $1.5 \ g$ of a non-volatile solute is dissolved in $100 \ mL$ of a solvent having a density of $0.8 \ g \ mL^{-1}$,which lowers its freezing point by $0.75 \ K$. (Freezing point depression constant for the solvent is $5 \ K \ kg \ mol^{-1}$).

Which of the following aqueous solutions has the highest freezing point?