s1.5 ideal gases

• relationship between volume, moles and molar volume

  volume (dm^3) = moles (mol) x molar volume (moldm^3)

  V = nVm
• molar volume at STP

  22.7
• assumptions made for ideal gases

  particles have a negligible volume

  particles are always in random motion

  no inter-particle forces

  collisions between particles are elastic

  average kinetic energy is directly proportional to temperature in K
• relationship between pressure and volume

  pressure and volume are inversely proportional at constant temperature

  P = 1/V
• relationship between volume and temperature

  volume and temperature (in K) are proportional at constant pressure

  V = T
• relationship between pressure and temperature

  pressure are temperature are proportional at constant volume

  P = T
• value of R

  8.31 JK^-1mol^-1
• when do real gases most deviate from ideal gases

  at low temperature and high pressure
• why do real gases deviate at high pressure

  there are more particles in a smaller space, so volume is no longer negligible

  attractive forces between particles increase, so collisions are not perfectly elastic
• combined gas law

  P1V1/T1 = P2V2/T2
• ideal gas equation

  PV = nRT