What happens to the vapor pressure of a solvent when a non-volatile solute is ad

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Question: What happens to the vapor pressure of a solvent when a non-volatile solute is added?

Options:

Correct Answer: It decreases

Solution:

The vapor pressure of a solvent decreases when a non-volatile solute is added due to the solute particles occupying space at the surface.

What happens to the vapor pressure of a solvent when a non-volatile solute is added?

What happens to the vapor pressure of a solvent when a non-volatile solute is added?

Correct Answer: The vapor pressure decreases.

Step 1: Understand what vapor pressure is. Vapor pressure is the pressure exerted by the vapor of a liquid when it is in equilibrium with its liquid phase.
Step 2: Know what a solvent is. A solvent is a substance that dissolves a solute, forming a solution. In this case, the solvent is a liquid.
Step 3: Identify what a non-volatile solute is. A non-volatile solute is a substance that does not easily evaporate and has little to no vapor pressure of its own.
Step 4: Recognize that when a non-volatile solute is added to a solvent, the solute particles mix with the solvent particles.
Step 5: Understand that the solute particles take up space at the surface of the liquid, which reduces the number of solvent particles that can escape into the vapor phase.
Step 6: Conclude that because fewer solvent particles can escape, the overall vapor pressure of the solvent decreases.

Raoult's Law – The principle that states the vapor pressure of a solvent is directly proportional to the mole fraction of the solvent in a solution.
Non-volatile Solute – A solute that does not vaporize and thus reduces the number of solvent molecules at the surface, leading to a decrease in vapor pressure.
Colligative Properties – Properties that depend on the number of solute particles in a solution, such as vapor pressure lowering, boiling point elevation, and freezing point depression.