Question

Which of the following aqueous molal solution have highest freezing point

• A. Urea
• B. Barium chloride
• C. Postassium bromide
• D. Aluminium sulphate

Answer 1

The correct option is A Urea

The depression in the freezing point is a colligative property and depends on the number of solute particles present in the solution.

as

$\Delta T_f=i{K}_{f}m$

$\Delta T_f\propto i$

$i_{urea}=1$ as Urea and glucose do not dissociate in solution.

$i_{BaC{l}_2}=2$ as on dissociation it give two ions

$i_{KBr}=2$ as on dissociation it give two ions

$i_{A{l}_2(S{O}_4{)}_3}=3$ as on dissociation it give ions

$\text{Therefore, the effective number of particles is minimum in urea, and it shows the lowest depression in freezing point.}$

$\text{Hence,Highest freezing point.}$