GENERAL

• H+ ions show that a substance is;

  acidic
• A strong acid

  fully dissociates
• OH- ions show a substance is:

  alkaline
• How does lubricating with oil prevent corrosion?

  Oil acts as a PHYSICAL barrier, oxygen and water can't be reached, so the metal substance does not corrode
• Why do metals have high boiling points?

  Strong forces of attraction between ions, high amounts of energy needed to overcome the attraction
• Why does aluminium have to be extracted by electrolysis?

  Aluminium is high in reactivity

  Aluminium cannot be reduced by carbon
• Why is percentage yield often less than 100 PERCENT?????

  Practical losses

  Competing reactions
• 18 carat gold

  Contains atoms of different sizes which prevents layers from sliding over one another, making it stronger than 24 carat gold
• Electrolysis

  Electrical energy decomposes substances
• Test for carbon dioxide

  1. Bubble the gas through lime water

  2. Limewater turns cloudy
• What happens in a neutralisation reaction?

  An acid and a base react, neutral solution is formed.