Question

Multiple choice-- 16 pts!

Answer 1

Answer: It decreases because nonvolatile aluminum and chloride ions now occupy some of the volume of the system.

Explanation:

Vapor pressure of a liquid  is defined as the pressure exerted by the vapors  in equilibrium with the liquid/solution at a particular temperature.

So, when a non-volatile solute is added to a solvent then its molecules align at the surface of liquid. As a result, less number of solvent molecules will escape from the solution. Thus, there will be decrease in vapors and thus the vapor pressure decrease.

The relative lowering of vapor pressure is directly proportional to the amount of dissolved solute.