C4

• How to calculate mole

  mass/relative formula mass
• How to calculate percentage yield?

  actual yield/theoretical yield x 100
• What are reasons why you may not get 100% yield?

  - Reactants may have reacted in a different way to make a different product

  - some product may be lost when separated from the reaction mixture

  - reactants may not go to completion
• Why do manufacturers use chemicals with high yields

  to help conserve resources, reduce waste and/or pollution
• How to calculate atom economy

  Mr (useful products) / Mr (total products) x100
• How to calculate concentration (mol/dm^3)

  moles/vol(dm^3)
• Why is atom economy important?

  - sustainable development

  - reduces production of unwanted products

  - it's safer

  - conserves raw materials and energy

  - it's more cost effective
• How to get to cm^3 ro dm^3

  divide 1000
• How to convert mol/dm^3 to g/dm^3

  multiply mol/dm^3 by Mr
• What is titration?


  the process of adding a known amount of solution of known concentration to determine the concentration of another solution
• What are the steps to titration

  1. rinse équipement with distilled water

  2. use a pipette/filler to measure 25cm^3 of sodium hydroxide and pour into flask and put over white tile

  3. add three or four drops of indicator to the flask

  4. fill burette with acid or base that u need to find the volume of

  5. add chemical from the burette to the conical flask

  6. swirl and add drops when u reach near the endpoint, stop when changes colour

  7. measure volume used from burette and repeat
• how to calculate moles of gas

  volume of gas (dm^3)/24dm^3
• How to calculate uncertainty

  range/2