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(C) The freezing point depression is a colligative property,given by the formula $\Delta T_f = i \cdot K_f \cdot m$,where $i$ is the van't Hoff factor

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$0.1 \ mol$ Urea in $1 \ kg$ water

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(C) The freezing point depression is a colligative property,given by the formula $\Delta T_f = i \cdot K_f \cdot m$,where $i$ is the van't Hoff factor and $m$ is the molality.Freezing point $T_f = T_f^0 - \Delta T_f$. To have the highest freezing point,the depression $\Delta T_f$ must be the minimum.$1$. For $0.1 \ mol \ KCl$: $i = 2$,$m = 0.1$,so $\Delta T_f \propto 2 	imes 0.1 = 0.2$.$2$. For $0.1 \ mol \ K_2SO_4$: $i = 3$,$m = 0.1$,so $\Delta T_f \propto 3 	imes 0.1 = 0.3$.$3$. For $0.1 \ mol$ Urea: $i = 1$,$m = 0.1$,so $\Delta T_f \propto 1 	imes 0.1 = 0.1$.$4$. For $30 \ g$ Glucose $(M = 180 \ g/mol)$: $m = \frac{30}{180} = 0.167 \ mol/kg$,$i = 1$,so $\Delta T_f \propto 1 	imes 0.167 = 0.167$.Comparing the values,the minimum $\Delta T_f$ is for $0.1 \ mol$ Urea. Thus,it has the highest freezing point.

Which of the following solutions has the highest freezing point?

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