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

first question = -65.9

second question = 100.9

Step-by-step explanation:

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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.

Kf is the molal depression constant of water (Kf = 4.70°C/m).

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

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

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