2. Physical Properties of Gases
Have mass
Are compressible
Fill their container
Move through each other (diffusion)
Exert pressure
Pressure depends on temperature

3. Kinetic Molecular Theory
(How gas molecules behave)
Very small particles
Distances between particles are large
In constant, random motion
Collisions are perfectly elastic
Kinetic energy depends of temperature of gas
Particles exert no force on each other

4. Pressure Pressure exerted by air = atmospheric pressure
(air has mass and is attracted by Earth’s gravity)
1 atm =
101,325 Pascal (Pa)
kiloPascals (kPa)
760 mm Hg
14.7 psi
29.92 inches Hg

5. Gas Laws Boyle’s Law: P1V1=P2V2 Lussac’s Law: P1/T1 = P2/T2
Charles’ Law: V1/T1 = V2/T2
Dalton’s Law: Ptotal = P1 + P2 + …
Ideal Gas Law: PV=nRT
R= atm*L/K*mol
All Temperatures must be in Kelvin! (oC+273)