Kinetic energy: the energy an object has because of its motion Kinetic molecular theory: states that all matter consists of tiny particles that are in constant motion Kinetic molecular theory as it applies to gases includes five postulates. WHAT IS KINETIC MOLECULAR THEORY? 1. Identify Provide an example of an object that has kinetic energy.

1 ST ASSUMPTION All matter is composed of small particles (atoms, or molecules.) The particles in a gas are considered to be small, hard spheres with an insignificant volume. These particles are FAR APART from each other. Between the particles there is EMPTY SPACE

2 ND ASSUMPTION These particles in a gas move rapidly in constant random motion. They travel in STRAIGHT paths and move INDEPENDENTLY of each other. Gases fill their container regardless of the shape and volume of the container. Uncontained gases diffuse into space without limits. Gas particles only change direction when they hit another gas particle or their container.

3 RD ASSUMPTION All collisions are perfectly elastic During collisions kinetic energy is transferred WITHOUT loss from one particle to another. And the Kinetic Energy always remains constant.

4 TH ASSUMPTION There are not forces of attraction or repulsion between gas particles. When particles collide they do not stick together but immediately bounce apart. Like playing POOL

During an elastic collision, kinetic energy is transferred without loss from one particle to another, and the total kinetic energy remains constant. KE = ½ mv 2 WHAT ARE THE POSTULATES OF KINETIC MOLECULAR THEORY?

The particles in helium gas at 200 K have twice the average kinetic energy as the particles in helium gas at 100 K. WHAT ARE THE POSTULATES OF KINETIC MOLECULAR THEORY?

2. Under ordinary conditions, the particles in a gas are __________. A.) Are vibrating in place & held closely together with very little kinetic energy B.) Contain enough kinetic energy to move in a circular motion inside their container. C.) Diffuses rapidly to fills their container with enough kinetic energy to completely overcome the attraction to other molecules D.) Slide past each other and are held loosely together with a definite volume

3. Which of the following is one of the assumptions of the Kinetic Molecular Theory? A. Gases consist of hard, small, spherical particles B. Particles are in constant random motion and have an insignificant volume C. Particles in a gas undergo perfectly elastic collisions. D. All of the above

4. Which of the following statements is true regarding the Kinetic Molecular Theory. A. Particles in a gas move in a circular motion and contain no kinetic energy. B. Particles in a gas move in a straight line and loose kinetic energy when they collide with each other and the walls of their container. C. Particles in a gas move in a straight line and do not loose kinetic energy when they collide with each other and the walls of their container. D. Particles in a gas move from side to side and contain no kinetic energy.

CHARLES’ LAW Jacque Charles His first hot air balloon

CHARLES’S LAW Volume of a fixed mass of gas at constant pressure varies directly with the Kelvin temperature Directly Proportional As one goes The other goes

Graphing Charles’ Law

BOYLE’S LAW Robert Boyle

BOYLE’S LAW P 1 V 1 = P 2 V 2 Inversely proportional As one goes the other goes Pressure 2x Volume 2x

Each of these flasks contains the same number of molecules. In which container is the pressure lowest? A. Flask 1 B. Flask 2 C. Flask 3 D. Flask 4

GAY-LUSSAC’S LAW Gay-Lussac

GAY-LUSSAC’S LAW The pressure of a fixed mass of gas at constant volume varies directly with the Kelvin temperature. Directly proportional As one goes the other goes

AVOGADRO’S LAW Equal volumes of gases at the same temperature and pressure contain equal numbers of molecules. The volume occupied by one mole of a gas at STP is called the Standard Molar Volume of a gas Standard Molar Volume of a gas = 22.4 L

HOW ARE THE VOLUME AND NUMBER OF MOLES OF AN IDEAL GAS RELATED? If the amount of gas in a container is increased, the volume increases If the amount of gas in a container is decreased, the volume decreases

Which of the tanks contains the greatest number of gas particles? A. tank 1 B. tank 2 C. tank 3 D. tank 4

The manufacturer of an aerosol packaged in a 150mL container wishes to produce a container of the same size that will hold twice as much gas. How will the pressure of the gas in the new product compare with that of the gas in the original container? A. The pressure decreases B. The pressure is not affected C. The pressure increases D. The pressure stays the same

THE COMBINED GAS LAW Expresses the relationship between pressure, volume and temperature of a fixed mass of gas. Combines Boyles and Charles Remember – Temperature must be in Kelvin

DALTON’S LAW John Dalton The same John Dalton as Dalton’s Atomic Theory

The total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases P Total = P 1 + P 2 + P 3 + P 4 + P 5... DALTON’S LAW OF PARTIAL PRESSURE

PARTIAL PRESSURE In a mixture of gases, the total pressure is the sum of the partial pressures of the gases. 4. Read Tables What is the partial pressure of oxygen in dry air? Composition of Dry Air ComponentVolume (%)Partial pressure (kPa) Nitrogen Oxygen Carbon dioxide 0.04 Argon and others Total

IDEAL GAS LAW The mathematical relationship among pressure, volume, temperature, and the number of moles of a gas. PV = nRT P = Pressure, V = Volume, n = Moles, R = Ideal Gas Constant, and T = temperature in Kelvin. R = L∙atm/ mol∙K R = 62.4 L∙mm Hg/ mol∙K