Corrosion & its prevention

Doors can be made from aluminium or wood.

Table 5 gives information about aluminium and wood.

Evaluate the use of aluminium and of wood for making doors.

Aluminium has an oxide coating that protects the metal from corrosion.

Explain how the oxide coating protects aluminium from corrosion.

Doors made from wood need painting to prevent rotting.

Paints are formulations made by mixing a solid pigment and a liquid.

Which statement describes the composition of a paint?

Tick () one box.

Doors can be made from aluminium or wood.

Table 3 gives information about aluminium and wood.

Evaluate the use of aluminium and of wood for making doors.

Aluminium has an oxide coating that protects the metal from corrosion.

Explain how the oxide coating protects aluminium from corrosion.

Doors made from wood need painting to prevent rotting.

Paints are formulations made by mixing a solid pigment and a liquid.

Which statement describes the composition of a paint?

Tick (✓) one box.

This question is about materials used to make bicycles.

Figure 6 shows a bicycle.

Table 3 shows information about two materials used to make bicycle frames.

Evaluate the use of aluminium alloy and of bamboo for making bicycle frames.

Use Table 3.

Explain why aluminium alloy bicycle frames do not need protection from corrosion.

Bicycle chains are made from an alloy of iron.

Bicycle chains rust without protection.

Paint is not used to protect bicycle chains from rusting.

Suggest how bicycle chains can be protected from rusting.

Bicycle frames can also be made from a composite of carbon fibres embedded in a polymer resin.

What description is given in this composite to:

the carbon fibre component

the polymer resin component?

This question is about the corrosion of metals.

The corrosion of iron is called rusting.

Plan an investigation to show that both water and air are needed for iron to rust.

You should include the results you expect to obtain.

Use apparatus and materials from the list:

• test tubes

• stoppers

• iron nails

• tap water

• boiled water

• drying agent

• oil.

A student investigated how the mass of three iron nails, A, B and C, increased after rusting.

Table 4 shows the student’s results.

Calculate X in Table 4.

Calculate the mean increase in mass of the three iron nails, A, B and C.

Use Table 4 and your answer to Question 06.2

This question is about the corrosion of metals.

The corrosion of iron is called rusting.

A student investigated the rusting of iron.

This is the method used.

1. Set up the test tubes as shown in Figure 4.

2. Leave the test tubes for 1 week.

3. Examine the nails for signs of rust.

Explain what would happen to the nails in each of the test tubes.

Magnesium is fixed to some steel ships.

Explain how this prevents the steel from rusting.

Explain why aluminium window frames do not corrode after they are made.