Structure & Bonding of Carbon (AQA GCSE Combined Science: Trilogy: Chemistry): Exam Questions

Figure 1 shows the structure of the diamond.

Figure 1

Diamond melts at temperatures above 4,800 ^oC. 

Explain why its melting point is so high.

Diamond is an extremely hard substance. 

Explain why, in terms of its bonding and structure.

Why can graphite conduct electricity?

Which statement about diamond is correct?

Graphene is a substance made from carbon which consists of a single layer of graphite just one atom thick. 

Scientists have recently developed a method to produce large sheets of a substance called graphene.

State two properties of graphene.

Figure 1 below shows the structure of graphene.

Figure 1

Use your knowledge of the bonding in graphene and Figure 1 to help you explain why graphene is such a strong material.

Use your knowledge of the bonding in graphene and Figure 1 to help you explain how graphene is able to conduct electricity.

A typical passenger jet contains many kilometres of electrical wiring made from copper.

This increases the mass of the aeroplane and consequently the fuel consumption.

Research is being carried out into replacing the copper wiring with much lighter carbon nanotubes.

Figure 1 shows the structure of a carbon nanotube.

Figure 1

Suggest a method of fabricating carbon nanotubes.

Carbon is a non-metal. 

Explain how the nanotube is able to conduct electricity.

Suggest a reason why carbon nanotubes are used as lubricants.

Buckminsterfullerene (also known as buckyballs) was the first fullerene to be discovered. 

The structure of buckminsterfullerene is shown in Figure 1 below.

Figure 1

State three uses of fullerenes (other than lubricants).

Using Figure 1 above to help you, describe the bonding and structure in Buckminsterfullerene.

Buckminsterfullerene is a slippery substance with a low melting point. Explain these observations.

The diagram shows the structure of a carbon nanotube. 

Which of the following is not a property of carbon nanotubes?

Graphite and diamond are different physical forms of the element carbon and have different properties. 

Their structures are shown in Figure 1 below.

  Figure 1

State the term used to describe elements which can have different physical forms while being in the same state.

Graphite is a much softer material than diamond.

Explain why.

Graphite is an electrical conductor but diamond is not.

Explain why.

Using your knowledge of the structure and bonding in graphite, justify its use in the “lead” filling in pencils.

Using your knowledge of the structure and bonding in graphite, justify its use as electrodes in electrolysis.

This question is about the bonding and structure of diamond.

State two uses of diamonds.

Figure 1 shows the outer electron shells of carbon atoms in a lattice structure of diamond.

Using dots, add electrons to the diagram to represent the bonding arrangement.

Figure 1

Explain why diamond has a high melting point.

This question is about allotropes of carbon.

Graphite and graphene are both allotropes of carbon. 

What is meant by an allotrope? 

The structures of graphite and graphene are shown in Figure 1. 

Figure 1

Compare graphite and graphene in terms of their bonding and structure.

Explain why graphite can be used as a lubricant.

Diamond is another allotrope of carbon.

Give two properties that are different to that of graphite.

This question is about fullerenes. 

Fullerenes can form nanotubes which consist of tiny carbon cylinders. 

A carbon nanotube is shown in Figure 1.

Figure 1

Explain the properties of carbon nanotubes.

Answer in terms of structure and bonding.

Carbon can react with oxygen to form carbon dioxide. 

Complete the dot and cross diagram in Figure 2 to show the bonding in this molecule.

Show the outer electrons only. 

Figure 2

Explain why carbon dioxide cannot conduct electricity. 

This question is about the properties and bonding in allotropes of carbon. 

Substance X is an allotrope of carbon and has the following properties and uses:

• It is strong

• It is a good conductor or electricity

• It is used to overlay monitor screens to make them touchscreen

Identify substance X.

Explain your answer.

Buckminsterfullerene is another allotrope of carbon.

Explain why this substance can be used as a lubricant. 

Fullerenes are also used as catalysts and in electronics.

Suggest why they can be used for these applications.

    catalysts: ____________________________________________ (1)

   electronics: ___________________________________________(2).

Explain how a catalyst increases the rate of a reaction.