C2d

C2d

1. Rusting

   • Salt water makes the rusting reaction much faster. In winter icy roads are treated with salt (so car bodies rust quicker)
   • Acid rain also increases the rate of rusting
   • Any reaction in which oxygen is added is called an oxidation reaction
     • iron + water + oxygen → hydrated iron(III) oxide

2. Aluminium does not rust - corrode. Its surface is protected by a natural layer of aluminium oxide. This prevents the metal below from coming into contact with air and oxygen. Unlike rust, which can flake off the surface of iron and steel objects, the layer of aluminium oxide does not flake off

3. Advantages and Disadvantages of Building Cars from Aluminium and Steel

   • S is stronger and harder than A
   • A is more malleable than S
   • A does not corrode as easily as S
   • A is less dense than S
   • S for a car body is cheaper than A

4. Advantages of Aluminium in Cars

   • A car with an aluminium body is lighter so has better fuel economy
   • Does not corrode as easily so car body has a much longer lifetime