1. I. Physical Properties Gases

2. 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.

3. B. Real Gases b Particles in a REAL gas… have their own volume attract each other (not far apart like ideal gases) b Gas behavior is most ideal… at low pressures at high temperatures in nonpolar atoms/molecules

4. 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

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

6. VolumeVolume Volume is the three-dimensional space inside the container holding the gas. The SI unit for volume is the cubic meter, m 3. A more common and convenient unit is the liter, l. Think of a 2-liter bottle of soda to get an idea of how big a liter is. (OK, how big two of them are…)

7. Amount (moles) SI unit for amount of substance is the mole, mol. Since we can’t count molecules, we can convert measured mass (in kg) to the number of moles, n, using the molecular or formula weight of the gas. By definition, one mole of a substance contains approximately 6.022 x 10 23 particles of the substance. You can understand why we use mass and moles! NEXTPREVIOUS MAIN MENU

8. D. Temperature ºF ºC K -45932212 -2730100 0273373 K = ºC + 273 b Always use absolute temperature (Kelvin) when working with gases.

9. E. Pressure Pressure is defined as the force the gas exerts on a given area of the container in which it is contained. The SI unit for pressure is the Pascal, Pa.

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

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

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