1. Chemistry An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 6 Gases 6.1 Properties of Gases 1

2. Chemistry An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Kinetic Molecular Theory A gas consists of small particles that move rapidly in straight lines have essentially no attractive (or repulsive) forces are very far apart have very small volumes compared to the volume of the container they occupy have kinetic energies that increase with an increase in temperature 2

3. Chemistry An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Properties That Describe a Gas Gases are described in terms of four properties: pressure (P), volume (V), temperature (T), and amount (n). 3

4. Chemistry An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Pressure Gas particles are very small and have lots of energy. Pressure is measure of collisions with sides of container. Gas particles in air exert pressure on us called atmospheric pressure. 4

5. Chemistry An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Volume The volume of a gas is the same as the volume of container it occupies. More collisions with sides of container will increase its volume. 5

6. Chemistry An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Temperature Temperature of gas is measured in Kelvin (K) temperature scale. Temperature of gas relates to the average kinetic energy of the molecules. Decrease temperature, molecules move less. Increase temperature, molecules move more. 6