1. I. Physical Properties 12.1- Gases

2. A. Kinetic Molecular Theory b kinetic-molecular theory: (def) theory of the energy of particles and the forces that act between them; based on idea that particles of matter are always in motion b Kinetic molecular theory describes the motion of an ideal gas

3. A. Kinetic Molecular Theory b ideal gas: (def) imaginary gas that perfectly fits the assumptions of the kinetic-molecular theory

4. A. Kinetic Molecular Theory b Particles in an ideal gas… have no volume. have elastic collisions. are in constant, random, straight- line motion. don’t attract or repel each other. have an avg. KE directly related to Kelvin temperature.

5. B. Real Gases b Particles in a REAL gas… have their own volume attract each other proposed by van der Waals b Gas behavior is most ideal… at low pressures at high temperatures in nonpolar atoms/molecules

6. C. Characteristics of Gases b Gases expand to fill any container. random motion, no attraction b Gases are fluids (like liquids). no attraction b Gases have very low densities. no volume = lots of empty space

7. C. Characteristics of Gases b Gases can be compressed. no volume = lots of empty space b Gases undergo diffusion & effusion. random motion

8. C. Characteristics of Gases b Diffusion: (def) process by which gases spontaneously spread out and mix with other gases; lighter gases diffuse more quickly b Effusion: (def) process by which gases particles under pressure pass through a tiny opening; lighter gases effuse faster

9. A. Temperature ºF ºC K -45932212 -2730100 0273373 K = ºC + 273.15 b Always use absolute temperature (Kelvin) when working with gases.

10. B. Pressure Which shoes create the most pressure? SI unit of force is the Newton

11. . Pressure b Barometer measures atmospheric pressure - at sea level, height of column is 760 mm - P of Hg is equal to the P of the atmosphere Mercury Barometer

12. E. Pressure b Manometer measures contained gas pressure - difference in height of tubes indicates the gas pressure U-tube Manometer

13. E. Pressure b KEY UNITS AT SEA LEVEL 101.325 kPa (kilopascal) 1 atm 760 mm Hg 760 torr 14.7 psi

14. PressurePressure UnitSymbolDefinitions PascalPaSI Pressure Unit; 1 Pa = 1 N/m 2 Millimeter of Mercury mm HgP that supports a 1 mm mercury column in a barometer Atmo- sphere atm1 atm = 760 mm Hg = 101.325 kPa Torrtorr1 torr = 1 mm Hg

15. C. STP Standard Temperature & Pressure 0°C 273.15 K 1 atm101.325 kPa -OR- STP

16. D. Dalton’s law b Dalton’s law of partial pressure: P total = P 1 + P 2 + P 3 …+P n (n = number of gases in mixture) **Total P exerted by collection gases is sum of pressure exerted by each gas