A solute added to a solvent raises the boiling point of the solution because:
A)The temperature to cause boiling must be great enough to boil not only the solvent but also the solute.
B)The solute particles lower the solvent's vapor pressure,thus requiring a higher temperature to cause boiling.
C)The solute particles raise the solvent's vapor pressure,thus requiring a higher temperature to cause boiling.
D)The solute increases the volume of the solution,and an increase in volume requires an increase in the temperature to reach the boiling point (derived from PV = nRT).
E)Two of the above are correct.

Question

Quizplus · Accepted Answer

When a solute is added to a solvent, it lowers the vapor pressure of the solvent. This is because the solute particles occupy space at the surface of the solution, making it harder for the solvent particles to escape and enter the gas phase. As a result, the solution's boiling point is raised, as a higher temperature is needed to make the vapor pressure equal to the surrounding pressure and cause boiling.

A Solute Added to a Solvent Raises the Boiling Point