The Behavior of Gases

Kinetic Theory explains… why gases are compressed more easily than liquids or solids

Kinetic Theory explains… their ability to expand and take shape and volume of their container

4 Variables used to describe a gas: Pressure Volume Temperature Number of moles

Factors Affecting Gas Pressure 1. Amount of gas 2. Volume 3. Temperature

Gas Laws 4 variables used to describe a gas P (kPa) V (L) T (K) Number of mol (n) How do they affect gas pressure?

Boyle's Law Effect of Pressure on Volume of a contained gas? (constant Temp) Decrease Pressure, _______________volume P α 1/V P is _________________ to V P1V1 = P2V2 As pressure doubles, volume ______________ 500 3 250 6 1000 1.5

Suppose you have a gas with 45. 0 ml of volume and a pressure of 760 Suppose you have a gas with 45.0 ml of volume and a pressure of 760.mm. If the pressure is increased to 800mm and the temperature remains constant, what will the new volume of the gas be?

Charles Law Effect of Temp on Volume (amount of gas and P, constant) As T of enclosed gas increases, V ___________ V α T (Kelvin) when P held constant V1/T1 = V2/T2 50 100 200 25

A soda bottle is flexible enough that the V of the bottle can change without opening it. If you have an empty soda bottle, V = 2 L, at room T of 25°C, what will the new volume be if you put it in your freezer?

Gay-Lussac’s Law What is the effect of T on P? (V is constant) P _____ T (Kelvin) As T doubles, P _____________ P1/T1 = P2/T2 300 100 600 200

If a gas in a closed container is pressurized from 15. 0 atm to 16 If a gas in a closed container is pressurized from 15.0 atm to 16.0 atm and its original temperature was 25.0°C, what would the final T of the gas be?

Combined Gas Law P, T, V relationship Only amount of gas is constant P1V1/T1 = P2V2/T2

In a lab experiment, 85.3 mL of a gas are collected at 24°C and a pressure of 733 mm Hg. Find the volume at STP.