What happens to the vapor pressure of a solvent when a volatile solute is added?
Practice Questions
Q1
What happens to the vapor pressure of a solvent when a volatile solute is added?
It increases.
It decreases.
It remains the same.
It becomes zero.
Questions & Step-by-Step Solutions
What happens to the vapor pressure of a solvent when a volatile solute is added?
Correct Answer: 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 volatile solute is. A volatile solute is a substance that can easily evaporate and turn into vapor.
Step 4: Recognize that when a volatile solute is added to a solvent, the solute molecules mix with the solvent molecules.
Step 5: Understand that the presence of solute molecules reduces the number of solvent molecules that can escape into the vapor phase.
Step 6: Conclude that because fewer solvent molecules can escape, the vapor pressure of the solvent decreases.
