Question

Which of the following best explains why vapor pressure is affected by adding solute to a solvent?

--Adding solute to the solvent increases the volume of solution therefore reducing the amount of space in a sealed container.
--Adding solute reduces the amount of surface area available for the solvent molecules to evaporate.
--Adding solute increases both the molality and the molecular weight of the solution.
--Adding solute disrupts the intermolecular forces between the solvent molecules.
--Adding solute disrupts the intermolecular forces between the solvent molecules.

Answer 1

@aaronq

Answer 2

@Callisto

Answer 3

@quickstudent

Answer 4

@dan815

Answer 5

@MelodicSymphony

Answer 6

can u help me

Answer 7

@aaronq

Answer 8

@dan815!!!!!!!!!!!!!!! MY HERO!

Answer 9

wassup dan! u lookin' fresh as always

Answer 10

lol

Answer 11

u have any ideas on this

Answer 12

I want to say its the first one

Answer 13

hmm ok, @dan815 what do u thiink?

Answer 14

i was thinking about the first one but im still not sure

Answer 15

https://www.khanacademy.org/science/chemistry/states-of-matter-and-intermolecular-forces/states-of-matter/v/vapor-pressure

Answer 16

"When a nonvolatile solute is added to a liquid to form a solution, the vapor pressure above that solution decreases. To understand why that might occur, let's analyze the vaporization process of the pure solvent then do the same for a solution. Liquid molecules at the surface of a liquid can escape to the gas phase when they have a sufficient amount of energy to break free of the liquid's intermolecular forces. That vaporization process is reversible. Gaseous molecules coming into contact with the surface of a liquid can be trapped by intermolecular forces in the liquid. Eventually the rate of escape will equal the rate of capture to establish a constant, equilibrium vapor pressure above the pure liquid.

If we add a nonvolatile solute to that liquid, the amount of surface area available for the escaping solvent molecules is reduced because some of that area is occupied by solute particles. Therefore, the solvent molecules will have a lower probability to escape the solution than the pure solvent. That fact is reflected in the lower vapor pressure for a solution relative to the pure solvent. That statement is only true if the solvent is nonvolatile. If the solute has its own vapor pressure, then the vapor pressure of the solution may be greater than the vapor pressure of the solvent.

Note that we did not need to identify the nature of the solvent or the solute (except for its lack of volatility) to derive that the vapor pressure should be lower for a solution relative to the pure solvent. That is what makes vapor pressure lowering a colligative property--it only depends on the number of dissolved solute particles.

summarizes our discussion so far. On the surface of the pure solvent (shown on the left) there are more solvent molecules at the surface than in the right-hand solution flask. Therefore, it is more likely that solvent molecules escape into the gas phase on the left than on the right. Therefore, the solution should have a lower vapor pressure than the pure solvent. "
-Sparknotes

Answer 17

so A?

Answer 18

@aaronq

Answer 19

@quickstudent

Answer 20

it was wrong sir

Answer 21

--Adding solute reduces the amount of surface area available for the solvent molecules to evaporate.

is always true but,

--Adding solute disrupts the intermolecular forces between the solvent molecules.

can also happen depending on the solute interacts