1. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 1 Chemistry FIFTH EDITION Chapter 5 Gases

2. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 2 Hypothetical Concept – No gas exactly follows the ideal gas law. Ideal Gas assumes 1) volumeless particles 2) particles do not interact.

3. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 3 Ideal Gases Hypothetical Concept Some come close at low pressure &/or high temperature. If Ideal Gas, the (P V)/ nRT = 1

4. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 4 Figure 5.24 Plots of PV/nRT Versus P for Several Gases (200 K)

5. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 5 Figure 5.25 Plots of PV/nRT Versus P for Nitrogen Gas at Three Temperatures Closest to ideal at high temperature

6. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 6 Must correct ideal gas behavior when at high pressure (smaller volume) and low temperature (attractive forces become important).

7. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 7 Ideal Gases Hypothetical Concept Ideal Gas assumes 1) volumeless particles 2) particles do not interact.

8. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 8 Figure 5.28 Consider factor for Volume Taken up by Gas Particles

9. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 9 Figure 5.26 Gas at Low (a) and High (b) Concentration In (a) few Interactions to Affect pressure. In (b) many More interactions So particles Exerts lower pressure on the wall.

10. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 10 Real Gases corrected pressure corrected volume P ideal V ideal Van der Waals Equation: Values of a & b are determined experimentally for a given gas.

11. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 11

12. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 12 Section 5.10 Lowest layer of Atmosphere is the Troposphere. Strongly Influences by Human Activities  Air Pollution.

13. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 13 Figure 5.29 The Variation of Temperature and Pressure with Altitude

14. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 14 Main sources of Air Pollution Transportation Production of energy

15. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 15 Read in detail pages 225 – 228. Study: the chemistry of polluted air which centers around the nitrogen oxides. Photochemical smog Pollution from burning coal Acid Rain Scrubbers

16. Copyright©2000 by Houghton Mifflin Company. All rights reserved. 16