Question

During the depression in freezing point experiment, equilibrium is established between the molecules of:
A. Liquid solvent and solid solvent
B. Liquid solute and solid solvent
C. Liquid solute and solid solute
D. Liquid solvent and solid solute

Answer 1

We must understand that the solute is the substance which is present in minor amounts whereas the solvent is the substance which is present in major amounts in solution.

Complete step to step answer:
Before answering the question let’s clear up the concept of solute and solvent. Solute’s are the minute component present in the solution whereas the solvent is the major component of the solution. So, we add solute into the solvent to form the solution or we can say we dissolve the solute into the solvent to get the solution.
Now, the concept of freezing point depression, It is the concept of depression in freezing point when we add non-volatile solute into the solution. Example of this can be salt in water.
Now, when we add solid into the liquid, the liquid is the solvent and the solid is the solute as solid is in less quantity. Now, since the solid is solute and the liquid is solvent so the equilibrium will be established between the liquid solvent and solid solute.

So, the answer to this question is D. liquid solvent and solid solute.

Additional Information:
The concept of freezing point depression is used in many industries. One example of such industry is refrigeration industry, in the refrigeration industry instead of water most of the time brine solution (water +$NaCl$) is used to transport the chilling effect. It is done because the water freezes at 0℃ whereas in case of brine due to freezing point depression it freezes at lower temperature than normal water.

Note: We must know that the concept of freezing point depression is used in many places; from questions to industries it has wide applications.Freezing point depression is the phenomena that describes why adding a solute to a solvent results in the lowering of the freezing point of the solvent. When a substance starts to freeze, the molecules slow down due to the decreases in temperature, and the intermolecular forces start to take over.It is a colligative property of solutions that is generally proportional to the molality of the added solute