Ideal gas molecules

• Gas laws:

  • Gas molecules have rapid and random motion.
  • When they hit the walls of the container, they exert a force.
  • Pressure = Force/Area
• Absolute zero:

  • At absolute zero the particles have no thermal energy or kinetic energy, so they cannot exert a force.
  • Absolute zero = 0 Kelvin = -273C
• As you increase the temperature of a gas, the kinetic energy of the gas particles increases and thus their average speed also increases.
• The Kelvin temperature of a gas is proportional to the average kinetic energy of its molecules.
• What happens to the kinetic energy of gas particles when heated?

  It increases
• How does heating a gas affect the average speed of its particles?

  The average speed increases
• What is the effect of increased particle speed on collisions with container walls?

  More collisions occur per second
• What happens to the force exerted on the walls of a container when gas particles collide more frequently?

  The force exerted increases
• What is the result of increased force exerted by gas particles on the walls?

  Total pressure rises
• What happens to the average speed of gas particles if the temperature is constant?

  It remains constant
• What occurs when the same number of gas particles is placed in a smaller volume container?

  They hit the walls more often
• How does the frequency of collisions change when gas particles are in a smaller volume?

  Collisions increase
• What is the effect of more collisions per second on the average force exerted on the walls?

  The average force increases
• How does the average force exerted on the walls relate to the number of collisions per second?

  More collisions lead to increased average force
• For a fixed mass of gas at constant volume, the pressure is directly proportional to the Kelvin temperature

  P1/T1 = P2/T2
• Boyle’s law:

  For a fixed mass of gas at constant temperature, the pressure is inversely proportional to the volume.

  p1V1 = p2V2