Formulations

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 fertilisers. Ammonium nitrate is a fertiliser containing nitrogen.

Complete the sentence. Choose the answer from the box.

Ammonium nitrate is produced by reacting ammonia with

Ammonium nitrate fertiliser is sold in 600 kg bags. A farmer spreads 40 bags of ammonium nitrate fertiliser on land with an area

Calculate the mass of ammonium nitrate fertiliser spread per m² of land.

A scientist works for a company which makes ammonium nitrate fertiliser. The scientist investigates the effect of different fertilisers on crop growth. The scientist concludes that the ammonium nitrate fertiliser improves crop growth more than other fertilisers. Suggest one reason why this conclusion might not be valid.

A different fertiliser containing nitrogen has the formula K₂NH₄PO₄

How many atoms of nitrogen are in the formula K₂NH₄PO₄?

Nitrogen and potassium in the fertiliser K₂NH₄PO₄ are important for good crop growth. Which other element in the fertiliser K₂NH₄PO₄ is important for good crop growth? Tick (✓) one box.

Some fertilisers are mixtures of different compounds in fixed proportions. What name is given to a mixture of different compounds in fixed proportions?

This question is about lithium carbonate.

Lithium carbonate is used in medicines.

Figure 7 shows a tablet containing lithium carbonate.

Lithium carbonate contains lithium ions and carbonate ions.

A student tested the tablet for lithium ions and for carbonate ions.

The student used:

• a metal wire

• dilute hydrochloric acid

• limewater.

Plan an investigation to show the presence of lithium ions and of carbonate ions in the tablet.

You should include the results of the tests for the ions.

The tablet also contains other substances.

The substances in tablets are present in fixed amounts.

What name is given to mixtures like tablets?

The tablet has a mass of 1.20 g and contains 700 mg of lithium carbonate.

Calculate the percentage by mass of lithium carbonate in this tablet.

This question is about lithium carbonate.

Lithium carbonate is used in medicines.

Figure 2 shows a tablet containing lithium carbonate.

Lithium carbonate contains lithium ions and carbonate ions.

A student tested the tablet for lithium ions and for carbonate ions.

The student used:

• a metal wire

• dilute hydrochloric acid

• limewater.

Plan an investigation to show the presence of lithium ions and of carbonate ions in the tablet.

You should include the results of the tests for the ions.

The tablet also contains other substances.

The substances in tablets are present in fixed amounts.

What name is given to mixtures like tablets?

The tablet has a mass of 1.20 g and contains 700 mg of lithium carbonate.

Calculate the percentage by mass of lithium carbonate in this tablet.

Methylated spirit is a useful product made from a mixture of substances. Table 1 shows the mass of the substances in a sample of methylated spirit.

What name is given to a useful product such as methylated spirit?

Calculate the percentage by mass of methanol in methylated spirit. Use Table 1.

Methylated spirit contains ethanol and is available cheaply. Methylated spirit also contains:

• pyridine which has a very unpleasant smell

• methyl violet which makes the mixture purple.

Suggest why pyridine and methyl violet are added to ethanol to make methylated spirit.

Suggest one use of methylated spirit.

Describe how ethanol is produced from sugar solution. Give the name of this process.

Figure 2 shows part of the displayed formula for ethanol. Complete Figure 2.

Name the gas produced when sodium is added to ethanol.

Methanol is used to produce methanoic acid. What type of substance reacts with methanol to produce methanoic acid?