1. States of Matter

2. The Kinetic-Molecular Theory Explains the properties of gases, liquids, and solids

3. Assumptions of the K-M Theory Particle Size  The particles of a gas are separated from one another by empty space

4. Particle Motion ◦ Gases are in constant, random motion ◦ Until they bump into something, they move in a straight line ◦ When they do collide with something, they do not lose kinetic energy  Such a collision is called ELASTIC  The energy of one particle may be transferred to another, but the total amount of energy stays the same

5. Particle Energy Kinetic Energy ◦ KE = ½ mv 2 ◦ All particles in the same gas have the same mass ◦ They do NOT have the same velocity

6. Temperature A measure of the AVERAGE KE of the particles in a sample of matter At a given temperature, all gases have the same average KE

7. K-M Theory Explains these behavior of gases ◦ Low Density ◦ Compression& Expansion ◦ Diffusion ◦ Effusion

8. Gas Pressure When gases collide with the walls of a container, they exert pressure on the walls Pressure is: ◦ Force per unit area The pressure exerted by our atmosphere is called atmospheric pressure, or air pressure

9. Air Pressure At the surface of the Earth, air pressure = 1 atm ◦ That’s about equal to the pressure exerted by a 1 kg mass on a square centimeter ◦ At higher altitudes, air pressure is less

10. Air Pressure Measured with a BAROMETER ◦ A thin tube closed on one end, and filled with Hg ◦ The Hg rises with the air pressure is higher, and falls when it is lower

11. A manometer is similar to a barometer, but has a valve that is opened between the tube and a flask containing a gas

12. Units of Pressure SI - pascal (Pa) ◦ 1 pascal = force of 1 newton per meter 2 Air pressure ◦ 1 atmosphere (atm) = 760 mm Hg ◦ = 760 torr ◦ = 101.3 kilopascals (kPa)

13. Dalton’s Law of Partial Pressure P total = P 1 + P 2 + P 3 …

14. 1)Pressure Problems What is the partial pressure of O2 gas in a mixture of N2 gas with a total pressure of 0.48 atm, if the partial pressure of N2 gas is 0.24 atm

15. 2)What is the pressure of: A mixture of 3 gases with the following partial pressures: ◦ 6.6 kPa ◦ 3.2kPa ◦ 1.2 kPa

16. 3)What is the pressure of: A mixture of 5 gases, with the following partial pressures: ◦ 7.81 kPa ◦ 13.20kPa ◦ 2.43 kPa ◦ 12.50 kPa ◦ 2500 Pa

17. Properties of Liquids Density & Compression

18. Fluidity The ability to flow Liquids are LESS fluid than gases

19. Viscosity A measure of the resistance of a liquid to flow. The stronger the intermolecular forces, the higher the viscosity The higher the mass of the particles, the higher the viscosity The higher the temperature, the lower the viscosity

20. Surface Tension A measure of the inward pull by particles in the interior of the liquid The stronger the attractions between particles, the greater the surface tension

21. Capillary Action The movement of a liquid up a narrow glass tube Occurs when adhesive forces are greater than cohesive forces Adhesion ◦ Force of attraction between molecules that are different Cohesion ◦ Force of attraction between identical molecules