1. I. Physical Properties Ch 12.1 & 13 Gases

2. Kinetic Molecular Theory 1. Particles of matter are ALWAYS in motion 2. Volume of individual particles is  zero. 3. Collisions of particles with container walls cause pressure exerted by gas. 4. Particles exert no forces on each other. 5. Average kinetic energy is proportional to Kelvin temperature of a gas.

3. A. Ideal Gases Ideal gases are imaginary gases that perfectly fit all of the assumptions of the kinetic molecular theory. Gases consist of tiny particles that are far apart relative to their size. Gas particles have elastic collisions No kinetic energy is lost in elastic collisions Gas particles are in constant motion. There are no attractive forces between gas particles The average kinetic energy of gas particles depends on temperature, not on the identity of the particle.

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

5. C. Characteristics of Gases b Gases expand to fill any container. b Gases are fluid like. b Gases have very low densities.

6. C. Characteristics of Gases b Gases can be compressed. lots of empty space b Gases undergo diffusion & effusion. random motion

7. C. Characteristics of Gases b Graham’s Law b Diffusion Spreading of gas molecules throughout a container until evenly distributed. b Effusion Passing of gas molecules through a tiny opening in a container

8. C. Characteristics of Gases KE = ½mv 2 b Speed of diffusion/effusion Kinetic energy is determined by the temperature of the gas. At the same temp & KE, heavier molecules move more slowly.  Larger m  smaller v

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

10. E. Pressure Which shoes create the most pressure?

11. E. Pressure b Barometer measures atmospheric pressure Mercury Barometer Aneroid Barometer

12. E. Pressure b Manometer measures contained gas pressure U-tube ManometerBourdon-tube gauge

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

14. F. STP Standard Temperature & Pressure 0°C 273 K 1 atm101.325 kPa -OR- STP