Diamond, graphite, graphene & fullerenes

This question is about structure and bonding.

Calcium sulfide is an ionic compound.

Figure 13 represents the structure of calcium sulfide.

Determine the empirical formula of calcium sulfide.

Calcium is in Group 2 of the periodic table.

Sulfur is in Group 6 of the periodic table.

Describe what happens when a calcium atom reacts with a sulfur atom.

Answer in terms of electrons and ions.

Figure 14 shows the structure of graphite.

Describe the structure and bonding of graphite.

Substances that consist of small molecules do not conduct electricity.

Give one reason why.

Methane consists of small molecules.

Poly(ethene) is a polymer.

Why does poly(ethene) have a higher melting point than methane?

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This question is about structure and bonding.

Calcium sulfide is an ionic compound.

Figure 2 represents the structure of calcium sulfide.

Determine the empirical formula of calcium sulfide.

Calcium is in Group 2 of the periodic table.

Sulfur is in Group 6 of the periodic table.

Describe what happens when a calcium atom reacts with a sulfur atom.

Answer in terms of electrons and ions.

Figure 3 shows the structure of graphite.

Describe the structure and bonding of graphite.

Substances that consist of small molecules do not conduct electricity.

Give one reason why.

Methane consists of small molecules.

Poly(ethene) is a polymer.

Why does poly(ethene) have a higher melting point than methane?

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This question is about carbon and carbon compounds.

An atom of carbon is represented as:

What is the number of protons in this atom of carbon?

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What is the number of neutrons in this atom of carbon?

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What is the number of electrons in this atom of carbon?

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Figure 10 shows the structure of a carbon compound.

Complete the formula of the carbon compound.

C__ F__

Methane:

• is a carbon compound

• exists as small molecules

• has a low boiling point.

What is the reason for the low boiling point of methane?

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Buckminsterfullerene (C₆₀) is a form of carbon.

Buckminsterfullerene was the first fullerene to be discovered.

What is the shape of a buckminsterfullerene molecule?

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Graphite is a form of carbon.

Figure 11 represents the structure of graphite.

How many covalent bonds does each carbon atom form in graphite?

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Diamond is another form of carbon.

Figure 12 represents the structure of diamond.

Describe the structure and bonding in diamond.

This question is about carbon.

Which type of substance is carbon? Tick (✓) one box.

Carbon has isotopes with mass numbers 12, 13 and 14. Complete the sentences. Choose answers from the box.

12 g of carbon contains 6.02 ×10²³ atoms. Which expression is used to calculate the mass of one atom of carbon? Tick (✓) one box.

Figure 2 shows diagrams that represent different forms of carbon.

Which diagram in Figure 2 represents Buckminsterfullerene? Tick (✓) one box.

Figure 3 represents part of the structure of graphite.

Draw one line from each property of graphite to the structural feature that is the reason for that property.

This question is about carbon and compounds of carbon.

Figure 9 shows diagrams that represent different structures.

Use Figure 9 to answer questions 06.1 and 06.2.

Which diagram represents graphite?

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Which diagram represents poly(ethene)?

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Figure 10 represents the structure of diamond.

How many covalent bonds does each carbon atom form in diamond?

Which is a property of diamond?

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Figure 11 shows a model of a molecule.

Complete the molecular formula of the molecule.

Molecular formula = C__ H__

Carbonic acid is a compound of carbon.

The formula of carbonic acid is H₂CO₃

Which ion is produced by carbonic acid in aqueous solution?

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Calculate the relative formula mass (M_r) of carbonic acid (H₂CO₃).

Relative atomic masses (A_r): H = 1 C = 12 O = 16

This question is about different forms of carbon. Figure 5 represents the structure of diamond.

Describe the structure and bonding of diamond.

Explain why diamond has a very high melting point.

Figure 6 represents the molecule C₇₀

What is the name of this type of molecule? Tick (✓) one box.

Molecules such as C₇₀ can be used in medicine to move drugs around the body. Suggest one reason why the C₇₀ molecule is suitable for this use.

Calculate the number of C₇₀ molecules that can be made from one mole of carbon atoms. The Avogadro constant = 6.02 × 10²³ per mole

Number of molecules =

This question is about carbon and its compounds.

Fullerenes are molecules of carbon atoms.

The first fullerene to be discovered was Buckminsterfullerene (C₆₀).

What shape is a Buckminsterfullerene molecule?

Give one use of a fullerene.

Propanone is a compound of carbon, hydrogen and oxygen.

Figure 13 shows the dot and cross diagram for a propanone molecule.

Complete Figure 14 to show a propanone molecule.

Use a line to represent each single bond.

Use Figure 13.

Figure 14

Determine the molecular formula of propanone.

Use Figure 13.

Propanone is a liquid with a low boiling point.

Why does propanone have a low boiling point?

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Figure 15 represents the structure of graphite.

Explain why graphite is:

• a good electrical conductor

• soft and slippery.

You should answer in terms of structure and bonding.

This question is about carbon and its compounds.

Fullerenes are molecules of carbon atoms. The first fullerene to be discovered was Buckminsterfullerene (C₆₀).

What shape is a Buckminsterfullerene molecule?

Give one use of a fullerene.

Propanone is a compound of carbon, hydrogen and oxygen. Figure 1 shows the dot and cross diagram for a propanone molecule.

Complete Figure 2 to show a propanone molecule. Use a line to represent each single bond. Use Figure 1.

Figure 2

Determine the molecular formula of propanone. Use Figure 1.

Propanone is a liquid with a low boiling point. Why does propanone have a low boiling point? Tick (✓) one box.

Figure 3 represents the structure of graphite.

Explain why graphite is:

• a good electrical conductor

• soft and slippery.

You should answer in terms of structure and bonding.

This question is about electrolysis. A student investigated the hypothesis: ‘The electrolysis of a salt solution produces a metal at the negative electrode and a gas at the positive electrode.’

Figure 4 shows the apparatus used.

What observation would be made at each electrode if the hypothesis is correct?

Table 3 shows the student’s results.

Which salt solution in Table 3 does not match the student’s hypothesis? Give one reason why.

Give two reasons why graphite is used for the electrodes.

A different student investigated what happens during electrolysis. Figure 5 shows the apparatus.

The purple crystal contained:

• colourless positive ions

• purple coloured negative ions.

The purple crystal dissolved in the electrolyte solution.

What happens to the purple coloured ions? Give one reason for your answer. Tick (✓) one box.

This question is about materials and their properties.

Figure 13 shows a carbon nanotube.

The structure and bonding in a carbon nanotube are similar to graphene. Carbon nanotubes are used in electronics because they conduct electricity. Explain why carbon nanotubes conduct electricity.

Figure 14 shows a badminton racket.

Table 4 shows some properties of materials. The materials could be used to make badminton racket frames.

Evaluate the use of the materials to make badminton racket frames. Use Table 4.

Zinc oxide can be produced as nanoparticles and as fine particles.

A nanoparticle of zinc oxide is a cube of side 82 nm Figure 15 represents a nanoparticle of zinc oxide.

Calculate the surface area of a nanoparticle of zinc oxide. Give your answer in standard form.

Some suncreams contain zinc oxide as nanoparticles or as fine particles. Suggest one reason why it costs less to use nanoparticles rather than fine particles in suncreams.

This question is about materials and their properties.

Figure 3 shows a carbon nanotube.

The structure and bonding in a carbon nanotube are similar to graphene. Carbon nanotubes are used in electronics because they conduct electricity. Explain why carbon nanotubes conduct electricity.

Figure 4 shows a badminton racket.

Table 1 shows some properties of materials. The materials could be used to make badminton racket frames.

Evaluate the use of the materials to make badminton racket frames. Use Table 1.

Zinc oxide can be produced as nanoparticles and as fine particles.

A nanoparticle of zinc oxide is a cube of side 82 nm Figure 5 represents a nanoparticle of zinc oxide.

Calculate the surface area of a nanoparticle of zinc oxide. Give your answer in standard form.

Some suncreams contain zinc oxide as nanoparticles or as fine particles. Suggest one reason why it costs less to use nanoparticles rather than fine particles in suncreams.

A student investigated the electrolysis of sodium chloride solution.

Figure 4 shows the apparatus.

The student measured the volume of gas collected in each measuring cylinder every minute for 20 minutes.

Figure 5 shows the volume of hydrogen gas collected in the measuring cylinder after 8 minutes.

What is the volume of hydrogen gas collected?

Figure 6 shows the results of the investigation.

Which of the lines on Figure 6 show that the volume of gas collected is directly proportional to the time?

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Which of the lines on Figure 6 show a positive correlation between the volume of gas collected and time?

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A teacher demonstrates the electrolysis of different substances using graphite electrodes.

Figure 7 shows the apparatus used.

Figure 7

Why can graphite conduct electricity?

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The teacher demonstrates the electrolysis of:

molten zinc chloride

potassium bromide solution.

Complete Table 3 to predict the products.

Choose answers from the box.

A student investigated the electrolysis of different substances. Figure 6 shows the apparatus.

Explain why electrolysis would not take place in the apparatus shown in Figure 6.

Explain why graphite conducts electricity. Answer in terms of the structure and bonding in graphite.

The student investigated how the volume of gases produced changes with time in the electrolysis of sodium chloride solution. Figure 7 shows the apparatus.

The student made an error in selecting the apparatus for this investigation. How should the apparatus be changed? Give one reason for your answer.

Another student used the correct apparatus. This student measured the volumes of gases collected every minute for 20 minutes. Figure 8 shows the student’s results.

Describe the trends shown in the results. Use values from Figure 8.

The number of moles of each gas produced at the electrodes is the same. No gas escapes from the apparatus. Suggest one reason for the difference in volume of each gas collected.

Calculate the amount in moles of chlorine collected after 20 minutes. Use Figure 8. The volume of one mole of any gas at room temperature and pressure is 24.0 dm³ Give your answer in standard form.