1. Chapter 10 States of Matter
The Nature of Gases
The Nature of Liquids
The Nature of Solids
Changes of State

2. Ch 10.1 The Nature of Gases Kinetic Theory Gas Pressure
Kinetic Energy and Kelvin Temperature

3. Kinetic Theory Name the three states of matter:
Solid
Liquid
Gas
How do you change phase?
Change Temperature

4. Kinetic Theory Kinetic Energy – The energy an object has due to motion
Kinetic Theory – Particles in all forms of matter are in constant motion

5. Assumptions of the Kinetic Theory as applies to Gases
A gas is composed of molecules or atoms that have insignificant volume and are spread very far apart. In between is empty space. No attractive or repulsive forces exist.
The particles in a gas move rapidly in constant random motion.
Travel in straight paths.
Change direction only when they collide.

6. Assumptions of the Kinetic Theory as applies to Gases
3) All collisions are perfectly elastic. Kinetic energy is transferred. It is never lost.

7. Gas Pressure
Gas Pressure – force exerted by a gas per unit of surface area.
Atmospheric Pressure – results from collisions of air molecules with objects
Barometers – measure atmospheric pressure

8. Gas Pressure Units SI Units – pascal (Pa) sea level = 101.3 kPa
Older Units – millimeters Mercury (mm Hg)
- Atmospheres (atm)
101.3 kPa = 760 mm Hg = 1 atm

9. Kinetic Energy and Kelvin Temperature
An increase in KE causes an increase in temperature. Particles speed up.
A decrease in KE causes a decrease in temperature. Particles slow down.
At –273.15ºC ( 0 K) all particles stop moving = absolute zero.

10. Kinetic Energy and Kelvin Temperature
Direct relationship
Particles in helium at 200 K have twice as much KE as particles at 100 K.

11. Ch 10.2 The Nature of Liquids
A Model of Liquids
Evaporation
Boiling Point

12. A Model of Liquids Particles in a liquid are moving.
They slide past each other.
They can flow
But, they are attracted to each other – intermolecular forces

13. A Model of Liquids
The particles in a liquid vibrate and spin while they move around.
All three of these motions contribute to the average Kinetic Energy.
In order to become a gas, the liquid particles must have enough KE to overcome the intermolecular forces.

14. A Model of Liquids
Intermolecular forces – cause liquid particles to be closer together.
More dense than gases
Increasing pressure has no effect on the volume of a liquid.

15. Evaporation Vaporization - conversion of a liquid to a gas or vapor
Evaporation – the process of vaporization occurring at the surface of a liquid when it is not boiling.

16. Evaporation Why do liquids evaporate faster when heated?
The added heat increases the KE of the liquids particles which allows the particles to overcome the intermolecular forces.
Evaporation is a cooling process – WHY?
The particles with the most heat escape first leaving those particles with less heat behind. The liquids temperature will decrease.

18. Vapor Pressure
A force due to the gas above a liquid.

19. Boiling Point
The point where vapor pressure of the liquid is just equal to the external pressure.
Boiling Points will change if the external pressure changes.
Normal Boiling Point – the boiling point of a liquid at kPa

20. Table H - Reference Table
Normal Boiling Point of Water-
100ºC
Boiling Point of water at 200 kPa-
118 ºC
Boiling Point of water at 50 kPa-
82 ºC
Describe the effect of pressure on waters boiling point.

21. Table H - Reference Table
Normal bp
Bp at 50 kPa
Bp at 150 kPa
Bp at 200 kPa
Propanone
Ethanol
Water
Ethanoic Acid

22. Table H - Reference Table
VP at 25 ºC
VP at 50ºC
VP at 75 ºC
VP at 100 ºC
Propanone
Ethanol
Water
Ethanoic Acid

23. High Altitude Cooking
Most high altitude cooking and baking instructions do not recommend compensations until you reach about 6000 ft above sea level.
Water boils at a lower temperature here - this is due to reduced air pressure.
Takes longer to cook food.

24. High Altitude Cooking

25. Chapter 10.3
A Model for Solids
Crystal Structure and Unit Cells

26. A Model for Solids Describe the movement of particles in a solid:
Vibrate around fixed points
Describe the structure of particles in a solid:
Packed against one another in a highly organized pattern
The density of liquids is ___high__.
Are solids compressible?
NO 

27. A Model for Solids Can solids flow? What does flow mean? NO
To move with a continual shifting of the component particles

28. A Model for Solids What 3 things happen when you heat a solid?
1) Particles vibrate more 
2) Organization of particles breaks down 
3) Melts

29. A Model for Solids Define melting point:
Temperature at which a solid becomes a liquid
Describe what the disruptive vibrations do at the melting point: 
Overcome interactions that hold the particles in a fixed postion
Fill in the diagram: 
melting 
Solid Liquid 
freezing

30. A Model for Solids Describe the melting points of:
Ionic Solids: High
  Molecular Solids: Low
What is an ionic solid?
Metal and nonmetal 
What is a molecular solid?
Two nonmetals

31. Crystal Structure and Unit Cells
Define crystal: 
Atoms, ions or molecules arranged in an orderly, repeating, three dimensional pattern called the crystal lattice
What determines the melting points of crystals? 
Type of bonding between atoms
What determines the shape of a crystal? 
Arrangement of particles within it

32. Crystal Structure and Unit Cells
List the 7 types of crystal systems:
Cubic
Tetragonal
Orthorhombic
Monoclinic
Triclinic
Hexagonal
Rhombohedal

33. Crystal Structure and Unit Cells
Define unit cell: 
Smallest group of particles within a crystal that retains the geometric shape
List the three forms of pure carbon: 
Diamond
Graphite
buckyball
What is an allotrope? 
Two or more different forms of the same element

34. Crystal Structure and Unit Cells
What is an amorphous solid? 
Solid that lacks an ordered internal structure
List examples of amorphous solids: 
Rubber, plastic, asphalt, glass
Describe glasses and associated properties: 
Super cooled liquids
Between a crystalline solid and a liquid
Doesn’t have a true melting point.

35. Answer these questions in your notes
How are the solid, liquid and gas states of water related on Earth?
What does freeze dried mean?
Why are freeze dried foods important?

36. Ch 10.4 Changes of State
Phase Diagrams
Sublimation

37. Phase Diagrams
Gives the conditions of temperature and pressure at which a substance exist as a solid, liquid or gas
Triple Point
The set of conditions when all three forms can exist

38. Normal Melting Point
                                                                                   
Normal Boiling Point
Triple Point

40. Sublimation
Can you dry your wash on a clothesline (outside) during winter?
Yes, your clothes will freeze solid, but then the ice will sublime into a vapor.
Sublimation – Change of a solid directly to a gas

42. Used to make freeze dried foods.

44. Dry Ice (-78ºC)

45. Solid Air Fresheners

46. Mothballs “Grandma’s House”

47. Phase Change Diagram