Phases and Colligative Properties Flashcards Preview

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Flashcards in Phases and Colligative Properties Deck (10)
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1
Q

Define Vapor Pressure

A

pressure do to escaped molecules from liquid surface at a given temperature

2
Q

What affects vapour pressure of a liquid?

A
  • temperature
  • pressure
    ^ both indicated on phase diagram
  • solute dissolved in the liquid
3
Q

Raoult’s Law

A

amount of solute dissolved in a liquid affects the vapor pressure of the liquid

4
Q

What is the common equation of pressure?

A

Pressure = Force / Area

5
Q

Does changing the amount of liquid in a container affect the vapor pressure? How so?

A
  • No!
  • Change amount of liquid = change volume
  • as volume changes, surface area changes
  • therefore pressure stays the same
  • change in molecules exerting force proportional change in surface area
6
Q

What is the definition of boiling temperature?

A

vapour pressure of solution equals atmospheric pressure of surroundings

7
Q

If you dissolve more solute in a solution, what happens to vapor pressure according to ____ law.

A

increase solute = decrease vapor pressure

- Raoult’s law

8
Q

As vapor pressure changes, what happens to boiling point?

A
  • decrease vapor pressure = increase boiling point

- more energy needed to be put into the system to reach equilibrium

9
Q

What is a non-volatile substance?

A

a substance that does not readily evaporate into a gas

10
Q

When adding solute to a pure solvent, what happens to freezing temperature?

A

( a decrease in vapour pressure due to addition of solute (Raoult’s))
- add solute
= decrease freezing point
- more solute to interfere with crystal lattice structure at freezing pt