Which of the following concentrations of solutions of urea in water exhibits minimum freezing point depression (in $\text{ m}$)?

$A$ fixed amount of glucose is dissolved in $100 \text{ g}$ water to form a solution that freezes at $-0.2^\circ\text{C}$. If the solution is cooled down to $-0.25^\circ\text{C}$, then ......... $\text{g}$ of ice would have separated.

When $4.5 \ g$ of a non-electrolyte solute is dissolved in $100 \ g$ of water,the freezing point of the solution is lowered by $0.465^o C$. The molar mass of the solute is ....... $g/mol$. (Given $K_f = 1.86 \ K \ kg \ mol^{-1}$)

Calculate the freezing point of a solution prepared by dissolving $1.8 \ g$ of glucose $(C_6H_{12}O_6)$ in $500 \ g$ of water. The $K_f$ value for water is $1.86 \ K \ kg \ mol^{-1}$. (in $K$)

$1.8 \ g$ of fructose is added to $2 \ kg$ of water. The freezing point of the solution is $(k_f = 1.86 \ K \ kg \ mol^{-1})$ (in $^\circ C$)

$1\%$ solution of $Ca(NO_3)_2$ has a freezing point: