1. Chapter 10 States of Matter

2. Section 1: The Kinetic-Molecular Theory of Matter

3. KMT
This is based on the idea that particles of matter are always in motion.
How it relates to gases:
Ideal gas = a hypothetical gas that perfectly fits all the assumptions of KMT.
No ideal gas actually exists; but some do come close.

4. 5 Assumptions
Gases consist of large numbers of tiny particles that are far apart relative to their size.
Collisions between gas particles and between particles and container walls are elastic collisions (no net loss of total kinetic energy)
Gas particles are in continuous, rapid, random motion. Thus, they have kinetic energy.

5. 5 Assumptions Cont.
There are no forces of attraction between gas particles.
This is why they have no set shape
The temperature of the gas depends on the average kinetic energy of the particles of the gas.

6. Properties of Gases No definite shape No definite volume
Ability to flow (fluid)
Low density
Can be compressed smaller
Diffusion
Effusion

7. Real Gases
A gas that does not behave completely according to the assumptions of KMT.
Noble gases and non-polar diatomic gases behave most like an ideal gas, as well as gases at high temperatures and low pressures.

8. Section 2 & 3: Liquids and Solids

9. Properties of Liquids No definite shape Higher density
Mostly incompressible so definite volume
Diffusion
Surface tension
Evaporation
Boiling
Can form solids

10. Properties of Solids Definite shape Definite volume
Defined melting point
High density
Incompressible
Low rate of diffusion

11. Types of Solids
Crystalline Solids: exist as single crystals or groups of crystals fused together.
Ionic Crystals
Covalent Network Crystals
Metallic Crystals
Covalent Molecular Crystals

12. Types of Solids
Amorphous Solids: are not arranged in a regular pattern.
Glass and Plastic

13. Chapter 10.4 Changes of State

14. Matter on earth can exist in any state—gas, liquid, or solid—and can change from one state to another.

15. Energy and Changes of State
When a substance changes from one state to another, energy is always involved.
The change will either be exothermic (releases heat) or endothermic (absorbs heat).

16. Changes of State Change of State Process Example Endo or Exo?
SolidLiquid
Melting
IceWater
SolidGas
Sublimation
Dry IceCO2
LiquidSolid
Freezing
WaterIce
LiquidGas
Vaporization
WaterSteam
GasSolid
Deposition
SteamIce
GasLiquid
Condensation
SteamWater

17. Phase Diagrams
Phase Diagram: a graph of pressure versus temperature that shows the conditions under which the phases of a substance exist.
Tells you what state a substance will be in at a certain temperature and pressure.

18. Triple point: the temperature and pressure conditions at which the three phases can coexist at equilibrium
Critical Point: the critical temperature and critical pressure of a substance.

19. Critical Temperature: the temperature above which the substance cannot exist as a liquid.
Critical Pressure: the lowest pressure at which the substance can exist as a liquid.

21. Name that state… Temperature Pressure State 70°C 2.0 atm 100°C 0.5 atm

23. Name that state… Temperature Pressure State 70°C 2.0 atm 100°C 0.5 atm
Liquid
Gas
Solid

24. Chapter 10.5 Water

25. Structure of Water
Recall: Water has 2 Hydrogen and 1 Oxygen and has a bent structure.
Ice forms a hexagonal pattern
Look at Fig 19 on pg 350
The empty spaces result in ices low density and are why it floats.

26. Properties of Water
Pure water is transparent, odorless, tasteless and almost colorless. Any odor or taste is caused by impurities.
Water freezes and ice melts at 0°C and 1 atm.
Molar enthalpy of fusion is kJ/mol
Water boils at 100°C and 1 atm.
Molar enthalpy of vaporization is kJ/mol

27. Going from ice to water requires energy.
Going from water to ice releases energy.
Going from water to steam requires energy.
Going from steam to water releases energy.
The amount of energy is the same, it is just either required or released.

28. Calculating Amount of Energy

29. Calculating Amount of Energy

30. Homework
Pg 351 #4, 6 and practice problem #1, 2