chem ch.13

a theory that describes the behavior of gases in terms of particles in motion

• kinetic molecular theory (KMT)

• gas

• temperature

• motion

assumptions of the KMT

• Particle size – small with mostly empty space between, and no attractive or repulsive forces among them

• Particle motion – random, straight line motion, with elastic collisions (no kinetic energy is lost → total KE=same)

• particle energy - kinetic energy is determined by mass (m) and velocity (v)

  KE = 1/2 mv^2

  KE and temperature are related

  Temperature is a measure of the average KE

gas behavior

• low density

  - density = mass/volume

• compression and expansion

  - because of the large amount of empty space between molecules

• diffusion and effusion

the movement of one material through another from an area a higher concentration to an area of lower concentration.

• diffusion

• effusion

the escaping of a gas through an opening.

• effusion

• diffusion

 the rate of effusion for a gas is inversely proportional to the square root of its molar mass

• Graham's Law of Effusion

• Dalton's Law of Partial Pressures

(gas pressure)

______ affect the pressure of a gas

• temperature

• volume

• number of moles

force per unit area

• pressure

• solid

• temperature

• energy

the particles in air exert pressure in every direction

• atmospheric pressures

• barometer

• hydrogen bonding

• surfactants

air pressure at higher altitudes than at sea level

• true

• false