1. I. Physical Properties (p. 399 – 402, 426-430) Ch. 13 - Gases Gases notes #1 - gas properties.ppt

2. In this lesson, you will learn: Physical properties of gases Real vs. ideal gas behavior Instruments for measuring gas pressure Units of temperature and pressure

3. Kinetic Molecular Theory 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 average kinetic energy (KE) directly related to Kelvin temperature.

4. Real Gases have their own volume attract each other Particles in a REAL gas… at low pressures at high temperatures in nonpolar atoms/molecules basically… when particles are far apart and don’t stick together Gas behavior is most ideal…

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

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

7. TemperatureTemperature ºF ºC K -45932212 -2730100 0273373 K = ºC + 273 Always use absolute temperature (Kelvins) when working with gases. No need to memorize this one! ↓ Memorize this one! ↓

8. Pressure Demos atmospheric pressure force & area

9. PressurePressure Which shoes create the most pressure?

10. PressurePressure Barometer measures atmospheric pressure Mercury Barometer Aneroid Barometer

11. PressurePressure Manometer measures contained gas pressure U-tube ManometerBourdon-tube gauge

12. PressurePressure KEY UNITS AT SEA LEVEL 101.325 kPa (kilopascal) 1 atm 760 mm Hg 760 torr 14.7 psi Memorize kPa, atm, mm Hg, and torr… You don’t need to memorize psi or that kPa = N / m 2

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