1. College Prep Chemistry Mr. Pompilii
Ch 10: States of Matter
College Prep Chemistry
Mr. Pompilii

2. States of Matter
1. Solid
2. Liquids
3. Gases

3. Colloids: (Definition: when one type of substance is evenly dispersed in another)
Ex) gas-liquids: foam, whipped cream
Ex) liquid-liquid: milk, mayonnaise
Ex) solid-liquid: blood, ink
Ex) liquid-gas: fog, mist, clouds
Ex) solid-gas: soot, smog
Ex) gas-solid: Styrofoam, pumice
Ex) liquid-solid: jelly, gelatin, jell-o

4. Gas dispersed throughout a liquid! That’s why it is light
What is Shaving Cream?
Gas dispersed throughout a liquid!
That’s why it is light
That’s why it’s form can change

5. Kinetic Theory: Kinetic Energy vs. Potential Energy
Energy in motion, energy at work.
Potential Energy:
Stored Energy
Energy with the capacity to do work

6. Chemical Kinetic or Chemical Potential???

7. Kinetic Theory
All particles of matter are in constant motion – even the solids!

8. 3- Assumptions about Gases from the Kinetic Theory
1. Gases are composed of tiny particles and mainly empty space
2. Gas particles move in rapid, constant, random motion
3. Collisions are perfectly elastic

9. Physical Properties of Gases:
Volume:
Shape
Molecular Motion
Density
Intermolecular Forces:
Avg. Kinetic Energy
Indefinite Volume
Indefinite Shape
Constant and Random
Relatively far apart
None
Constant: Elastic collisions

10. 3- Variables that describe a Gas
1. Volume – measured in mL, L, or cm3
2. Temperature – measured in oC or K

11. 3- Variables that describe a Gas:
3. Pressure – force acting on an object
A push or a pull
Atmospheric Pressure

12. Units that describe Pressure:
SI Units:
Pascal (Pa) are very small so we use kilopascal (kPa)
1000 Pa = 1 kPA
101.3 kPa = standard pressure

13. Other units that describe Pressure:
1 atmosphere (atm)
Because there is 1 atmosphere’s worth of air above you at sea level
1 atm = kPa
mmHg (millimeters of mercury)
1 atm = 760 mmHg= kPa
Torr:
1 atm = 760 torr = kPa

14. Converting Pressure Units
1 atm = 760 mm Hg = 760 torr = kPa
All units are equal to one another in these quantities!

15. Example Problem
How many millimeters of mercury does a gas exert at atm of pressure?

16. Example Problem Given: 2.40 atm Unknown: ? mm Hg
Conversion Factor: 1 atm = 760 mm Hg
Solve:
2.40 atm x 760 mm Hg/ 1atm = mm Hg

17. Device used to measure pressure Developed by Evangelista Torricelli
Barometer
Device used to measure pressure
Developed by Evangelista Torricelli

18. Barometer at Sea Level

19. Sect. 10-2: Nature of Liquids

20. Sect. 10-2: Nature of Liquids
Volume
Shape
Molecular Motion
Density
Intermolecular forces
Avg. Kinetic Energy
Definite volume
Indefinite Shape
Vibrate, flow and spin
More Dense than gas
Yes
Lower than gas

21. Vaporization
Definition: term used for the conversion of a liquid to a gas or vapor below its boiling point
General term for the escape of molecules at the surface
Can be an open or closed container

22. Evaporation – vaporization of an open container

23. Vaporization in a closed container:
Vapor Pressure: vaporized particles collide with the walls of a sealed container, and create a pressure above the surface of the liquid.
Some particles vaporize, others condense
Ex) The “Sssst” in soda!

24. Dynamic Equilibrium
Equilibrium reached between particles vaporizing and particles condensing

25. Boiling
Boiling Point (bp): the temperature at which the vapor pressure of the liquid is just equal to the external pressure
Bubbles form throughout the solution
The vapor pressure inside these bubbles is equal to the atmospheric pressure
Boiling and evaporation are cooling processes. Why?

26. Different from Boiling Point!
Normal Boiling Point: the boiling point of a liquid at 1 atm
lower pressures = lower boiling point
not as much force holding particles in the solution
higher pressure = higher boiling point
more force on the surface of the liquid

27. Vapor Pressure

28. Distillation Apparatus

29. Distillation: A separation process
Uses the specific boiling point of each liquid to separate a mixture of liquids
Boiling point is a physical property and unique to each substance
As a substance is boiling the temperature remains CONSTANT regardless of how much energy is added to the system

30. Sect. 10-3: Nature of Solids
Volume
Shape
Molecular Motion
Density
Intermolecular forces
Avg. Kinetic Energy
Definite volume
Definite Shape
Vibrate on a fixed point
More Dense than liquids
Yes
Lower than liquids

31. Solids – have repeating patterns called crystals

32. Crystal Structure & Crystalline Shapes

33. Allotropes– different forms of the same element
Carbon
Examples of Carbon allotropes:
1. Graphite
2. Diamond
3. Bucky Ball
4. Carbon- 540
5. Carbon – 70
6. Carbon- nanotubes

34. Graphite:

35. Diamond

36. Buckminsterfullerene: Buckyball Carbon - 60

37. Carbon-70
Another Fullerene
Hollow ball
Used for nanotechnology

38. Carbon- 540
Another Fullerene
Hollow ball
Used in nano- technology

39. Carbon- nanotubes Stronger than diamonds Good conductors of heat
Can be used as conductors or semi- conductors

40. Amorphous Solids Lack ordered internal structure
Ex) Rubber, plastic, asphalt, glass
Glass: Supercooled Liquids

41. Melting Point
Melting Point (mp): the temperature at which the solid turns into a liquid
Melting points and freezing points are the same temperatures

42. Section 10.4 College Prep Chemistry
Phase Changes
Section 10.4
College Prep Chemistry

43. Summary of Phase Changes

44. Phase Diagrams:
Shows the temperature and pressures at which a substance exists as a solid, liquid or gas.
Triple Point:
Point where all three curves meet
Point at which all three phases exist in equilibrium
Critical Point:
Highest temperature and pressure at where a liquid and gas can coexist at equilibrium

45. Heat Curves: shows the temperatures at which phase changes occur

46. Heat Curve for Water:

47. Sublimation – solid phase to gas

48. Deposition – gas phase to solid