AQA GCSE Chemistry (8462), Higher tier · Bonding, structure and the properties of matter › Structure and bonding of carbon
Practise Graphite. 14 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy4 marks
Graphite is a form of carbon.
(a) How many covalent bonds does each carbon atom form in graphite?[1]
(b) Graphite is used in pencils. Which property makes graphite suitable for this use? Tick (✓) one box.[1]
It is soft and slippery.
It is very hard.
It has a low melting point.
It is transparent.
(c) The layers in graphite are made of rings of carbon atoms. How many carbon atoms are in each ring? Tick (✓) one box.[1]
4
5
6
8
(d) Graphite conducts electricity. Which particles carry the charge through graphite?[1]
Show the answer and mark scheme
(a)Answer: 3
3
(b)Answer: It is soft and slippery.
(c)Answer: 6
(d)Answer: delocalised electrons
(delocalised) electrons
Question 2Medium6 marks
Graphite is a form of carbon.
(a) Explain why graphite is soft and slippery.[3]
(b) Explain why graphite conducts electricity.[3]
Show the answer and mark scheme
(a)Answer: Graphite is made of layers with no covalent bonds between them (only weak forces), so the layers can slide over each other.
graphite has layers (of carbon atoms)
there are no covalent bonds between the layers / only weak forces between the layers
so the layers can slide over each other
(b)Answer: Each carbon atom forms only three bonds, so one electron from each atom is delocalised; these electrons move through the structure carrying charge.
each carbon atom forms three covalent bonds
(so) one electron from each carbon atom is delocalised
the delocalised electrons move through the structure / along the layers, carrying charge
Question 3Hard6 marks
Diamond and graphite are both forms of carbon. Diamond is used to make the tips of drills. Graphite is used as a lubricant and to make electrodes.
Compare the structure and bonding of diamond and graphite. Use your answer to explain why each substance is suitable for its uses.[6]
Show the answer and mark scheme
Answer: Both are giant covalent carbon. Diamond: 4 bonds per atom, rigid 3D — very hard (drill tips), no delocalised electrons. Graphite: 3 bonds per atom, layers with no bonds between them — slippery (lubricant); one delocalised electron per atom — conducts (electrodes). Both have very high melting points.
both are giant covalent structures containing only carbon atoms
in diamond, each carbon atom forms four covalent bonds with other carbon atoms
diamond has a rigid three-dimensional structure so it is very hard, which makes it suitable for drill tips
in graphite, each carbon atom forms three covalent bonds, forming layers of hexagonal rings
there are no covalent bonds between the layers (only weak forces), so the layers slide over each other and graphite is slippery, which makes it a good lubricant
in graphite, one electron from each carbon atom is delocalised, so graphite conducts electricity and can be used for electrodes
diamond has no delocalised electrons, so it does not conduct electricity
both have very high melting points because many strong covalent bonds must be broken, so they are not damaged at high temperatures
Marked with levels of response: the full level descriptors are in the app.