Question

Determine the freezing point of a 0.51 molal

solution of benzoic acid in chloroform. Chloroform
has a freezing point of -63.5°C and a freezing
point depression constant of 4.70°C.kg/mol.
What is the freezing point of this solution?
°C

Answer 1

-65.9 and 100.9

Step-by-step explanation:

Hope this helps

Answer 2

-65.897°C.

Step-by-step explanation:

• Adding solute to water causes depression of the boiling point.

• The depression in freezing point (ΔTf) can be calculated using the relation: ΔTf = Kf.m,

where, ΔTf is the depression in freezing point of chloroform solution.

Kf is the molal depression constant of chloroform (Kf = 4.70°C.kg/mol).

m is the molality of the solution (m = 0.51 m).

∴ ΔTf = Kf.m = (4.70°C.kg/mol)(0.51 m) = 2.397°C.

∴ The freezing point of the solution = (freezing point of chloroform) - ΔTf = (-63.5°C) - (2.397°C) = -65.897°C.