2.3 The ideal gas equation

• Equal amounts of moles of gases occupy the same volume under the same conditions of temperature and pressure.
• The volume of one mole of any gas at room temperature and pressure (20 degrees C and 1 atmosphere pressure) is 24 cubic decimetres.
• In an "ideal gas":

  • the particles are extremely small, so the gas doesn't occupy any spaces
  • the ideal gas has constant, random and straight-line motion
  • no forces between the particles of the gas. particles only collide elastically with eachother and the walls of the container.
• The volume of real gas is much larger than that of ideal gas, and the pressure of real gas is lower than that of ideal gas. All real gases tend to perform ideal gas behaviour at low pressures and relatively high temperatures.
• pV =nRT
• p = pressure in Pa
• V = volume in m3
• n= number of moles
• T = temperature in K (degrees C + 273)
• density (g/cm3) = mass (g) / volume (cm3)
• 1 m3 = 1000 dm3 = 1000000 cm3
• Questions may involve the same amount of gas under different conditions.

  since 'n' stays the same, simplify to P1 V1 = P2 V2