BEHAVIOR OF GASES SPS5b. Relate temperature, pressure, and volume of gases to the behavior of gases.

Activator Sketch the graph and draw the molecular motion of the water molecules for each section of the graph. IV V III II I

Behavior of Gases SPS2b. Relate temperature, pressure, and volume of gases to the behavior of gases.

What is pressure? A measure of the force applied over a unit area.

Pressure Examples Tire (pounds per square inch, (psi)) Inflating a football Car tire pressure decreases when it is cold outside

PROPERTIES OF GASES No definite shape/volume Expands to fill its container Easily compressed (squeezed into a smaller container) Compressibility is a measure of how much the volume of matter decreases under pressure Gases are easily compressed because of the space between the particles in a gas

PROPERTIES OF A GAS Factors Affecting Gas Pressure Amount of Gas Increase amount, increase pressure Volume Reduce volume, increase pressure Temperature Increase temperature, increase pressure Relationship between pressure, temperature, and volume is explained through the Gas Laws

GAS LAWS Boyle’s Law Charles’ Law Gay-Lussac’s Law Combined Gas Law Ideal Gas Law Dalton’s Law of Partial Pressure Graham’s Law

BOYLE’S LAW If the temperature is constant, as the pressure of a gas increases, the volume decreases For a given mass of gas at constant temperature, the volume of a gas varies inversely with pressure As volume goes up, pressure goes down As volume goes down, pressure goes up P1V1 = P2V2

BOYLE’S LAW Real Life Example As you push on the end of a syringe, the volume inside the syringe decreases as the pressure on the syringe increases

CHARLES’ LAW As the temperature of an enclosed gas increases, the volume increases, if the pressure is constant The volume of a fixed mass of gas is directly proportional to its Kelvin temperature if the pressure is kept constant As volume goes up/down, temperature goes up/down V1 = V2 Temperature must be in Kelvin! T1 T2

CHARLES’ LAW Real Life Example Balloon Lab-As the temperature of the water is increased, the volume of the balloon is increased. Coke Can-Fill a coke can with a small amount of water, as you heat the water inside to near boiling, immediately invert the coke can into ice-cold water so the coke can is experiencing a dramatic drop in temperature, volume of can will decrease (can will crush in on itself)

GAY-LUSSAC’S LAW As the temperature of an enclosed gas increases, the pressure increases, if the volume is constant The pressure of a gas is directly proportional to the Kelvin temperature if the volume remains constant

GAY-LUSSAC’S LAW Real Life Example Tires The faster a car goes, the higher the temperature of the tire gets and the higher the pressure inside the tires

DALTON’S LAW In a mixture of gases, the total pressure is the sum of the partial pressure of the gases Partial pressure is the contribution each gas in a mixture makes to the total pressure At constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures of the component of gases