Science week 2

• Kinetic molecular theory


  Helps us understand the different properties of gases at the molecular level
• Kinetic molecular theory


  • Gases are composed of molecules
  • Distances between molecules are far greater than the molecules' dimensions
  • Molecules are in constant random motion
  • Molecules frequently collide with one another
  • Collisions between molecules are perfectly elastic
  • Attractive and repulsive forces are absent
  • Average kinetic energy of gas molecules is directly related to temperature
• Avogadro's law


  Relates the number of moles and volume of a gas, which are directly related when pressure and temperature are held constant
• Ideal gas law


  Combines Boyle's law, Charles' law, and Avogadro's law into a single equation: pV = nRT
• Units for ideal gas law
• Gay Lussac's Law


  Relates pressure and temperature
• Pressure and temperature


  Directly proportional if volume and amount of substance are constant
• Formula for Gay Lussac's Law

  p1/t1 = p2/t2
• Subscripts 1 and 2

  1 refers to initial state, 2 refers to final state
• Pressure must be expressed in pressure units, temperature must be in Kelvin
• To convert Celsius to Kelvin, add 273
• Solving Gay Lussac's Law problems


  1. Identify given information (p1, t1, p2 or t2)

  2. Rearrange formula to solve for unknown (t2 or p2)

  3. Substitute values and calculate

  4. If final temperature in Celsius, convert back from Kelvin
• Gay Lussac's Law


  The pressure of a given amount of gas held at constant volume is directly proportional to the Kelvin temperature