Question

Arrange the following aqueous solutions in order of decreasing freezing point, and explain your reasoning.

0.5 m HCl, 0.5 m glucose, 0.5 m acetic acid

Answer 1

Freezing point depression.delT = kf*m i =freezing point of solvent- freezing point of solution

i is amount of particle in solution

m= molality

Assuming kf to be same as that for water

Freezing point depression is proportioanl to molality.

Which has got low molality, wil give low depresion in freezing point

since molality is same for all the solutions

i is more for HCl hence depresion in freezing point is more and hence freezing point of solution is less

i for CH3COOH is more than Glucose and and less than HCl hence its freezing point is more than HCl and less than glucsoe

Glucsoe wil have highest freezing point

the order of freezing point is

HCL< CH3COOH< Glcuose