Kinetic Molecular Theory

• Gas


  least compact

  most mobile

  move with high velocity

  has kinetic energy

  uniformly distributed within a container (confined)
• General Characteristics


  no definite shape and volume

  diffuse readily

  will mix easily when combined

  can be compressed readily
• Density


  grams per liter

  low densities are from large amount of space between molecules
• Kinetic Molecular Theory


  behavior of gases

  gas molecules as a tiny particle

  a molecule will collide with any objects in its path (another molecule or the container)

  bounces away like a billiard ball (elastic collision)
• Gases consist of very tiny molecules, the distance separating them is larger than the molecules, making it negligible. Volume occupied by gas is mostly empty space
• There is no force of attraction between and among the gas molecules. The molecules thus, move freely as far as space will allow.
• Gas molecules are in constant, random, and straight line motion. They will collide with each other and with the walls of the container. No energy is lost during collisions.
• Pressure is exerted when particles hit the sides of the container
• Collisions of gas molecules are perfectly elastic. This means no energy is lost as friction when molecules collide.
• The average kinetic energy of gas molecules is directly proportional to the absolute temperature (Kelvin) and it's the same for all gases at the same temperature. The speed that the particles move increases with increasing temperature.
• moles or grams


  amount of a gas or its mass

  mass of gases is negligible
• Volume


  amount of space occupied by the gases

  L and mL
• Temperature

  measure of hotness or coldness of an object

  proportional to the average kinetic energy

  in kelvin (273 K)
• Pressure 


  average effect of the forces of the colliding molecules

  atm, torr, psi, cmHg or mmHg

  P = F/A