Memory Anchor:

• Super Challenge:

  Stretch:

  Challenge:

Key Questions:

1. (Chem only) Do all gases occupy the same volume?
   • Equal amounts in moles of gases occupy the same volume under the same conditions of temperature and pressure.
2. (Chem only) What volume does one mole of any gas occupy at room temperature and pressure?
   • A single mole of any gas will occupy 24dm3
3. (Chem only) How could you calculate the volume a gas would occupy if you were given the mass of gas made?
   • 1) Calculate the total number of moles of that gas you have (Moles = Mass (g) / Mr) 2) Then calulate the volume that gas would occupy. Volume of gas (dm3) = Moles x 24
4. (Chem only) If you have 88g of CO2. What volume would it occupy?
   • 1) Calculate moles first: moles = mass /Mr = 88/44 = 2 2) Calculate the volume of gas made: Volume of gas = Moles x 24 = 2x24 = 48dm3
5. (Chem only) In the reaction CH4 2O2 ? CO2 2H2O (at rtp) what volume of water vapour is produced when 2.4 dm3 of methane burns?
   • 1) Rearrange volume equation for moles to find moles of methane reacting: moles (methane) = volume / 24 moles (methane) = 2.4 / 24 moles (methane) = 0.1 2) Identify molar ratio for reactants and products in question: 1 mole of methane products 2 moles of water, therefore 1:2 ratio 3) Deduce the moles of water using ratio: 0.1 x 2 = 0.2 moles 4) calculate volume of water vapour: volume of gas = moles x 24 volume of gas = 0.2 x 24 = 4.8dm3
6. (Chem only) Rearrange the volume of gas equation to calculate the number of moles
   • Rearrange volume equation for moles to find moles of methane reacting: moles (methane) = volume / 24