Depression of Freezing Point
Depression of Freezing Point: Overview
This topic covers concepts such as freezing point, depression in freezing point, anti-freezing agents and molal freezing point depression constant using molar heat of fusion.
Important Questions on Depression of Freezing Point
Calculate the freezing point of a solution containing glucose, of water. The freezing point of pure water is and for water is

The freezing point of a solution containing of acetic acid in of benzene is lowered by . The molar mass (g/mol) of acetic acid from this data and the value of van’t Hoff factor would be (for benzene, )


De-icing is the process of removing snow, ice or frost from a surface. In extremely cold regions, car windows get covered by ice reducing the visibility. The image below shows the de-icing of the window of a car during extreme cold using a fluid.
Which of the following compounds could be present in the de-icing fluid used above?

An aqueous solution containing of a solute of molar mass in a certain mass of water freezes at . The mass of water in grams present in solution is

An aqueous solution of sodium chloride freezes below . Explain the lowering in freezing point of water with the help of a suitable diagram.

At of a non-volatile solid (molar mass ) when added to water, lowered its freezing point by . What is (in ) ( of water at )

The freezing point depression constant of benzene is . Assuming dimerization of acetic acid in benzene, the freezing point depression of solution of acetic acid is

of urea when dissolved in of certain solvent decreases its freezing point by . of an unknown compound when dissolved in of the same solvent depresses the freezing point by . Calculate the molar mass of the unknown compound.
(Molar mass of urea )

What is a de-icing agent? How does it work?

What freezes out first when a solution of common salt is cooled?

Why is camphor preferred as a solvent in finding the molecular mass of naphthalene by Rast method?

Which of the following solution will have the lowest freezing point and why ? solution glucose solution solution

Which of the following solution will have the lowest freezing point and why? solution glucose solution solution.


Between glucose solution and glucose solution, which one has a lower freezing point?

Give one most important application of the phenomenon of depression in the freezing point in everyday life.

Define molal depression constant/ cryoscopic constant.


