The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a nonvolatile solute dissolved in this solvent.
-Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved in the solvent?
A)Curve (a)is the solvent and the vapor pressure decreases.
B)Curve (a)is the solvent and the vapor pressure increases.
C)Curve (b)is the solvent and the vapor pressure decreases.
D)Curve (b)is the solvent and the vapor pressure increases.

Question

The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a nonvolatile solute dissolved in this solvent. 
-Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved in the solvent?
A)Curve (a)is the solvent and the vapor pressure decreases. 
B)Curve (a)is the solvent and the vapor pressure increases. 
C)Curve (b)is the solvent and the vapor pressure decreases. 
D)Curve (b)is the solvent and the vapor pressure increases.

Quizplus · Accepted Answer

In the diagram, curve (a) is the vapor pressure curve for the pure solvent, while curve (b) is the vapor pressure curve for the solution containing the nonvolatile solute. The addition of a nonvolatile solute to a solvent causes a decrease in the vapor pressure of the resulting solution. Therefore, the correct choice is A, as curve (a) is the solvent and the vapor pressure decreases when a nonvolatile solute is dissolved in the solvent.

The Following Diagram Shows a Close-Up View of the Vapor