Chemistry Chapter 14 Study Guide

Kinetic Theory of Gases
1) Indefinite shape and volume
2) Made up of particles in rapid, constant, random motion
3) Temperature changes greatly affect the volume of a gas
4) All collisions between particles in a gas are perfectly elastic – no loss of energy
5) Point masses – no volume or diameter – so small and far apart
Ideal Gas
Composed of molecules with mass but with no volume and no mutual attraction between the molecules
Gas Pressure
Results from the force exerted by a gas per unit surface area of an object
Vacuum
Empty space with no particles and no pressure
Atmospheric Pressure
Results from the collisions of atoms & molecules in the air with objects
Barometer
Device used to measure atmospheric pressure
SI Unit of Pressure
Pascal, kPa
Older Units Used
mm Hg & atmospheres
Standard Atmospheric Pressure
101.3 kPa
Standard Temperature
0 C = 273 K
Kinetic Energy
Energy of motion
Absolute zero
Temperature at which the motion of all particles theoretically ceases (0 K, -273.15 C)
Kelvin Temperature Scale
Reflects the relationship between temperature and average kinetic energy
Gas Properties
1) Compressibility
2) Has mass
3) Fills container
4) Exerts pressure
5) Diffuses through other gases
Pressure of Gas Depends on 3 Factors
1) Number of molecules
2) The volume the molecules are in
3) Average kinetic energy of molecules
Boyle’s Law
Pressure & volume; if the amount & temperature of gas remain constant, the pressure exerted by the gas varies inversely as the volume
Charles’s Law
Temperature & volume; the volume of a fixed mass of gas, held at a constant pressure varies directly with the Kelvin temperature
Gay-Lussac’s Law
Pressure & Temperature; the pressure of a gas is directly proportional to the Kelvin temperature if the volume remains constant
Ideal Gas Law
Describes the behavior of an ideal gas