ANS:C - vapor pressure lowering

The addition of a non-volatile solute to a solvent produces all of the following effects:

1. Freezing point elevation: The presence of a non-volatile solute in a solvent lowers the vapor pressure of the solution, which leads to a decrease in the freezing point of the solution compared to the pure solvent. This phenomenon is known as freezing point elevation.
2. Boiling point depression: Similarly, the presence of a non-volatile solute in a solvent also lowers the vapor pressure of the solution, which leads to an increase in the boiling point of the solution compared to the pure solvent. This phenomenon is known as boiling point depression.
3. Vapor pressure lowering: The presence of a non-volatile solute in a solvent reduces the number of solvent molecules at the surface of the solution, which lowers the vapor pressure of the solution compared to the pure solvent. This phenomenon is known as vapor pressure lowering.