1. All gases consist of small particles
States of Matter
Kinetic-Molecular Theory – describes the behavior of gases
Three assumptions:
All gases consist of small particles
Constant random motion experiencing elastic collisions
Kinetic energy depends on mass and velocity. At a given temperature, all gases have the same kinetic energy.

2. K.E. = ½ mv2
m mass in kg
v velocity m/s
K. E. Proportional to temperature
Consider Nitrogen and oxygen at room temp.
Which one has higher K.E.?
Which one has faster moving molecules?

3. Behavior of gases Low density Compression and expansion
Diffusion-movement of one material through another
Effusion-gas escaping through a small hole
Graham’s law

4. Consider gas 1 and gas 2 at room temp.
Do page

5. Gas Pressure Pressure – force per unit area
Barometer – measures atm pressure
At sea level at 0 degrees C, average air pressure is 760. mm Hg. This is the same as 1.00 atm or 760. torr or kPa
Be able to do conversions
Manometer – measures gas pressure in a closed container (see page 389)
Open manometers

6. Dalton’s law of partial pressures – the individual pressures add up to the total
Do page

7. Forces of Attraction Intermolecular forces
Dispersion forces - weak forces due to a temporary induced dipole
Exist between all particles but only significant if they are the only forces present
Explains why Cl2 and F2 are gases but Br2 is a liquid and I2 is a solid
Dipole-dipole
Hydrogen bonds

8. Liquids Density and compression Fluidity
Viscosity – resistance to flow, decreases with temperature
Surface tension
Surfactants
Capillary action

9. Solids Density Crystalline Simple cubic cell Body-centered cubic cell
Face-centered cubic cell

11. Molecular solids
Covalent network solids (macromolecular)
Ionic solids
Metallic solids
Amorphous solids

12. Phase changes Melting Vaporization Vapor pressure
Boiling – know this definition
Sublimation
Condensation
Deposition
freezing

13. Phase Diagrams

14. q = mass X change in temp X specific heat
q = mass X enthalpy
For water: specific heat of steam is 2.02 J/g C
specific heat of liquid is 4.18 J/g C
specific heat of ice is 2.06 J/g C
Enthalpy of fusion is 334 J/g
Enthalpy of vaporization is 2260 J/g

15. Energy and change in state
How much energy is needed to convert 10.0 g of ice at degrees C to steam at degrees C?

16. Energy and change in state
How much energy is needed to melt 25.4 grams of iodine? The enthalpy of fusion of iodine is 61.7 J/g.

17. How much energy is needed to melt 4. 24 grams of Pd
How much energy is needed to melt 4.24 grams of Pd? The enthalpy of fusion of Pd is 162 J/g.

18. Find the heat needed to raise the temperature of 5
Find the heat needed to raise the temperature of 5.58 kg of iron from 22.0 degrees C to degrees C.

19. Find the energy change when 28
Find the energy change when 28.9 g of copper is cooled from it’s melting point to 25.0 degrees C. Is this energy gained or released and how can you tell?

20. Coffee cup calorimeter

21. example
A 2.35 g sample of unknown metal at degrees C is placed in 50.0 ml of water originally at 23.0 degrees C. The maximum temperature of the water is 23.3 degrees C. What is the specific heat of the unknown metal?

22. Ice lab
Design a lab that allows you to find the molar heat of fusion of ice.