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Chemistry C2 Foundation Questions
Q1. Here is a word equation for a chemical reaction.
copper oxide + sulphuric acid copper sulphate + water
Write down everything that the word equation tells you about the reaction.
...............................................................................................................................................
...............................................................................................................................................
............................................................................................................................................... (Total 4 marks)
Q2. The drawing shows a container of a compound called magnesium chloride.
(i) How many elements are joined together to form magnesium chloride?
.................................................................................................................................... (1)
(ii) Magnesium chloride is an ionic compound. What are the names of its ions?
................................................. ions and ................................................. ions (1)
(iii) How many negative ions are there in the formula for magnesium chloride?
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.................................................................................................................................... (1)
(iv) Complete the sentence.
Ions are atoms, or groups of atoms, which have lost or gained
......................................... . (1)
(v) Suggest three properties which magnesium chloride has because it is an ionic compound.
Property 1 ...................................................................................................................
....................................................................................................................................
Property 2 ..................................................................................................................
....................................................................................................................................
Property 3 ..................................................................................................................
.................................................................................................................................... (3)
(Total 7 marks)
Q3. The diagram shows the apparatus for an experiment. Hydrated copper sulphate crystals were heated. They became anhydrous copper sulphate.
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(a) Name a suitable piece of equipment to heat tube A.
..................................................................................................................................... (1)
(b) Use words from the box to complete the two spaces in the table. You may use each word once or not at all.
black blue orange red purple white
Name Colour
Hydrated copper sulphate crystals ...................................................
Anhydrous copper sulphate ....................................................
(2)
(c) What is the purpose of the ice and water in the beaker?
.....................................................................................................................................
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..................................................................................................................................... (1)
(d) Drops of a clear, colourless liquid formed on the inside of tube B.
(i) Name the liquid.
........................................................................................................................... (1)
(ii) Explain how the liquid came to be inside tube B.
...........................................................................................................................
...........................................................................................................................
........................................................................................................................... (2)
(e) Anhydrous copper sulphate can be turned into hydrated copper sulphate. What would you need to add? Apart from the change in colour, what could you observe?
.....................................................................................................................................
.....................................................................................................................................
..................................................................................................................................... (2)
(f) Copper sulphate can be made from black copper oxide by reacting it with an acid. Name the acid.
..................................................................................................................................... (1)
(Total 10 marks)
Q4. (a) Every chemical element has a chemical symbol. Choose the correct chemical symbols from the box and complete the three spaces in the table.
C Co Cu Fe I Ir Zn Zr
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Name of element Chemical symbol
Copper ....................................
Iron ....................................
Zinc ....................................
(3)
(b) Give one use for each of the following metals. You should give a different use for each metal.
Copper ......................................................................................................................
....................................................................................................................................
Iron ...........................................................................................................................
....................................................................................................................................
Zinc ...........................................................................................................................
.................................................................................................................................... (3)
(c) Give four physical properties which metals usually have.
1. ................................................................................................................................
....................................................................................................................................
2. ................................................................................................................................
....................................................................................................................................
3. ................................................................................................................................
....................................................................................................................................
4. ................................................................................................................................
.................................................................................................................................... (4)
(d) Metals usually form ionic compounds. Give one property of an ionic compound.
....................................................................................................................................
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.................................................................................................................................... (1)
(e) The diagrams show two different atoms, atom A and atom B.
Atom A Atom B
(i) Complete the following sentence.
For these two atoms to become ions one ............................................ would
be transferred from atom ........... to atom ........... . (1)
(ii) Atom A and atom B are from different elements. How can you tell this from their nuclei?
...........................................................................................................................
........................................................................................................................... (1)
(Total 13 marks)
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Q5. Calculate the percentage of iron in iron sulphate (FeSO4).
(Relative atomic masses: Fe = 56, O = 16, S = 32)
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Percentage of iron in iron sulphate = ..........................% (Total 3 marks)
Q6.Hydrated copper sulphate is a blue solid. When it is heated, white solid anhydrous copper sulphate is made. This is a reversible reaction.
hydrated copper sulphate [+ heat energy] anhydrous copper sulphate + water (blue) (white)
(a) To make the forward reaction work, the hydrated copper sulphate must be heated all the time.
What type of reaction is this?
.....................................................................................................................................
..................................................................................................................................... (1)
(b) Anhydrous copper sulphate can be used in a test for water. What two things will happen when water is added to anhydrous copper sulphate?
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
..................................................................................................................................... (2)
(Total 3 marks)
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Q7. Hydrogen peroxide (H2O2) contains the same elements as water (H2O).
(a) Name the hazard symbol shown by using the correct word from the box.
corrosive flammable oxidising toxic
(1)
(b) Hydrogen peroxide decomposes in the presence of a catalyst.
2H2O2(aq) → 2H2O(l) + O2(g)
(i) Complete the word equation for this chemical reaction.
hydrogen peroxide → water + ................................ (1)
(ii) What does a catalyst do to a chemical reaction?
...........................................................................................................................
........................................................................................................................... (1)
(Total 3 marks)
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Q8. Nitrates, such as ammonium nitrate, are added to soil to help plant growth.
(a) When rain falls nitrates dissolve and can end up in drinking water. Nitrates in drinking water can stop respiration in babies. This only happens if there is a lot of nitrate in the drinking water.
Plants use nitrates for growth. Humans need plants. Should large amounts of nitrates be added to soil? Give two reasons for your answer.
Answer ......................................................................................................................
Reason 1 ....................................................................................................................
....................................................................................................................................
Reason 2 ....................................................................................................................
.................................................................................................................................... (2)
(b) The amount of nitrogen in a nitrate compound is important.
(i) How many nitrogen atoms are there in the formula of ammonium nitrate, NH4NO3
..........................................................................................................................
(1)
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(ii) Calculate the percentage of nitrogen in ammonium nitrate, NH4NO3.
(Relative atomic masses: H = 1; N = 14; O = 16)
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
Percentage of nitrogen in ammonium nitrate = ........................................... % (3)
(Total 6 marks)
Q9. (a) You may find the Data Sheet helpful to complete the word equation.
These two gases react as shown in the balanced symbol equation.
2H2 + O2 → 2H2O
Complete the word equation for this reaction.
hydrogen + ............................... → ...................................... (2)
(b) Complete this sentence by crossing out the two words in the box that are wrong.
This chemical reaction is much faster if a molecule if a is used. (1)
(Total 3 marks)
Q10. Calcium oxide (quicklime) is made by heating calcium carbonate (limestone).
calcium carbonate → calcium oxide + carbon dioxide
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100 g ? 44 g
(a) 44 grams of carbon dioxide is produced when 100 grams of calcium carbonate is heated.
Calculate the mass of calcium oxide produced when 100 grams of calcium carbonate is heated.
....................................................................................................................................
mass ......................... g (1)
(b) What mass of carbon dioxide could be made from 100 tonnes of calcium carbonate?
mass ....................... tonnes (1)
(Total 2 marks)
Q11. As the world population increases there is a greater demand for fertilisers.
(a) Explain what fertilisers are used for.
....................................................................................................................................
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....................................................................................................................................
....................................................................................................................................
.................................................................................................................................... (2)
(b) The amount of nitrogen in a fertiliser is important.
(i) How many nitrogen atoms are there in the formula, NH4NO3?
......................................................................................................................... (1)
(ii) Work out the relative formula mass of ammonium nitrate, NH4NO3.
Relative atomic masses: H 1; N 14; O 16.
...........................................................................................................................
...........................................................................................................................
Relative formula mass of ammonium nitrate = ............................... (1)
(Total 4 marks)
Q12. (a) The diagram shows one way of making crystals of copper sulphate.
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(i) Why was the solution filtered?
.......................................................................................................................... (1)
(ii) How could you make the crystals form faster from the copper sulphate solution?
.......................................................................................................................... (1)
(iii) The chemical equation is shown for this reaction.
CuO(s) + H2SO4(aq) → CuSO4(aq) + H2O(l)
In the chemical equation what does (aq) mean?
.......................................................................................................................... (1)
(b) Blue copper sulphate crystals go white when warmed. How could you use the white copper sulphate as a test for water?
....................................................................................................................................
....................................................................................................................................
.................................................................................................................................... (2)
(Total 5 marks)
Q13. (a) The flow diagram shows the stages in the production of nitric acid.
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Give the names of the compounds labelled as A, B and C on the flow diagram. Choose names from the box.
ammonia nitrogen nitrogen dioxide nitrogen monoxide
A ........................................................................
B.........................................................................
C ........................................................................ (3)
(b) Use the flow diagram to help you name two raw materials used to make nitric acid.
............................................................... and ............................................................... (2)
(c) Reaction 1 uses a catalyst.
(i) How does a catalyst help this reaction?
...........................................................................................................................
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(1)
(ii) Draw a ring around the name of the catalyst used in reaction 1.
copper iron platinum vanadium (1)
(Total 7 marks)
Q14. A student investigated some instant soup.
(a) Instant soup contains a food additive which has the formula:
NaH2PO4
Give the names of all the elements in this compound.
The periodic table on the Data Sheet may help you to answer this question.
.....................................................................................................................................
..................................................................................................................................... (2)
(b) The student investigated the reaction which takes place when soup powder is added to cold water.
The student thought that the reaction might be exothermic.
(i) What is meant by the term exothermic reaction?
...........................................................................................................................
........................................................................................................................... (2)
(ii) Describe an experiment that the student could do to prove that this reaction is exothermic.
To gain full marks in this question you should write your ideas in good English. Put them into a sensible order and use the correct scientific words.
...........................................................................................................................
...........................................................................................................................
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...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
........................................................................................................................... (4)
(Total 8 marks)
Q15. Salts can be prepared by the reaction of acids with alkalis.
(a) (i) The reactions of acids with alkalis can be represented by the equation below. Choose a substance from the box to complete the equation.
carbon dioxide hydrogen oxygen water
acid + alkali → salt + .......................................................... (1)
(ii) Draw a ring around the word which best describes the reaction.
displacement neutralisation oxidation reduction (1)
(b) Sodium sulphate is an important salt.
The table gives a list of some substances.
Put a tick ( ) next to the names of the acid and the alkali that would react to make sodium sulphate.
Substances ( )
Hydrochloric acid
Nitric acid
Potassium sulphate
Sodium hydroxide
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Sodium nitrate
Sulphuric acid
(2) (Total 4 marks)
Q16. A student did two experiments using ammonium chloride.
(a) In the first experiment the student heated a small amount of ammonium chloride in a test tube.
Two reactions take place in the test tube.
Reaction 1 ammonium chloride → ammonia + hydrogen chloride (colourless gases)
Reaction 2 ammonia + hydrogen chloride → ammonium chloride
(i) Complete the sentences by crossing out the incorrect word in each box.
Reaction 1 takes place at a high low
temperature.
Reaction 2 takes place at a high low
temperature.
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(1)
(ii) Draw a ring around the word which best describes reactions 1 and 2.
combustion displacement oxidation reduction reversible (1)
(iii) Suggest a reason for the mineral wool at the top of the test tube.
...........................................................................................................................
........................................................................................................................... (1)
(b) In the second experiment the student mixed a small amount of ammonium chloride with some water in a beaker.
The temperature of the water was measured before and after adding the ammonium chloride.
Temperature before adding the ammonium chloride
20°C
Temperature after adding the ammonium chloride
16°C
Draw a ring around the word which best describes the process which takes place.
combustion displacement endothermic exothermic freezing (1)
(Total 4 marks)
Q17. Ammonium nitrate and potassium chloride are both salts. They can be made by neutralisation reactions.
Choose substances from the box to complete the word equations for the formation of these two salts.
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ammonia hydrochloric acid nitric acid
potassium nitrate water potassium hydroxide
ammonia + ........................................ → ammonium nitrate + water
.................................. + hydrochloric acid → potassium chloride + .......................... (Total 3 marks)
Q18. This label was on a bottle of stain remover.
When ‘Simply Amazing’ is mixed with water a reaction takes place which produces bubbles of oxygen gas.
(i) Suggest a method that you could use to measure how quickly this reaction takes place.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
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.....................................................................................................................................
.....................................................................................................................................
..................................................................................................................................... (2)
(ii) Read the instructions on the label and then suggest how increasing the temperature of the water affects the rate of this reaction.
.....................................................................................................................................
..................................................................................................................................... (1)
(iii) Suggest one other way in which the rate of a reaction can be changed.
.....................................................................................................................................
..................................................................................................................................... (1)
(Total 4 marks)
Q19. A student heated some blue copper sulphate crystals. The crystals turned into white copper sulphate.
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(a) The blue copper sulphate had to be heated to change it into white copper sulphate.
State whether the reaction was exothermic or endothermic. ....................................
Explain your answer.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b) The word equation for this reaction is shown below.
(i) What does the symbol tell you about this reaction?
.......................................................................................................................... (1)
(ii) How could the student turn the white powder back to blue?
.......................................................................................................................... (1)
(Total 3 marks)
Q20. Nitric acid can be neutralised by alkalis to make salts.
(i) The salt called potassium nitrate can be made from nitric acid.
Complete the word equation for this neutralisation reaction. Choose the correct substances from the box.
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hydrogen oxygen potassium chloride
potassium hydroxide water
nitric acid + ................................ →potassium nitrate + ................................ (2)
(ii) Ammonium nitrate is another salt made from nitric acid.
Which one of the following is the main use of ammonium nitrate? Draw a ring around your answer.
dye fertiliser plastic fuel (1)
(iii) Complete this sentence by choosing the correct ion from the box.
H+ NH4+ NO3
– O2– OH–
The ion that makes solutions acidic is ............................................................ . (1)
(Total 4 marks)
Q21. Chromatography was used to compare three of the colours used to coat the chocolate sweets.
What do these results tell you about these three colours?
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..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
..............................................................................................................................................
.............................................................................................................................................. (Total 3 marks)
Q22. (a) Read the article about the use of nanoparticles in sun creams.
Sun creams
Many sun creams use nanoparticles. These sun creams are very good at absorbing radiation, especially ultraviolet radiation. Owing to the particle size, the sun creams spread more easily, cover better and save money because you use less. The new sun creams are also transparent, unlike traditional sun creams which are white. The use of nanoparticles is so successful that they are now used in more than 300 sun cream products.
Some sun creams contain nanoparticles of titanium oxide. Normal-sized particles of titanium oxide are safe to put on the skin.
It is thought that nanoparticles can pass through the skin and travel around the body more easily than normal-sized particles. It is also thought that nanoparticles might be toxic to some types of cell, such as skin, bone, brain and liver cells.
(i) How is the size of nanoparticles different from normal-sized particles of titanium oxide?
.......................................................................................................................... (1)
(ii) Suggest how the size of nanoparticles might help them to enter the body more easily.
..........................................................................................................................
.......................................................................................................................... (1)
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(b) Give two advantages of using nanoparticles in sun creams.
1 .................................................................................................................................
....................................................................................................................................
2 .................................................................................................................................
.................................................................................................................................... (2)
(c) Why might nanoparticles be dangerous inside the body?
...................................................................................................................................
................................................................................................................................... (1)
(Total 5 marks)
Q23. (a) The diagram represents an atom of nitrogen.
(i) Use words from the box to label the diagram.
electron neutron nucleus proton
(2)
(ii) Draw a ring around the mass number of this atom.
5 7 14 21 (1)
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(b) Nitrogen can react with hydrogen to make ammonia, NH3 .
Which diagram, A, B, C or D, best represents an ammonia molecule? (1)
(Total 4 marks)
Q24. Instant cold packs are used to treat sports injuries.
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One type of cold pack has a plastic bag containing water. Inside this bag is a smaller bag containing ammonium nitrate.
The outer bag is squeezed so that the inner bag bursts. The pack is shaken and quickly gets very cold as the ammonium nitrate dissolves in the water.
(a) One of the statements in the table is correct.
Put a tick ( ) next to the correct statement.
Statement ( )
The bag gets cold because heat energy is given out to the surroundings.
The bag gets cold because heat energy is taken in from the surroundings.
The bag gets cold because plastic is a good insulator.
(1)
(b) Draw a ring around the word that best describes the change when ammonium nitrate dissolves in water.
electrolysis endothermic exothermic (1)
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(c) Suggest and explain why the pack is shaken after the inner bag has burst.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
..................................................................................................................................... (2)
(Total 4 marks)
Q25. Bricks made from silica (silicon dioxide) are used to line furnaces that operate at high temperatures.
Part of the structure of silica is shown in the diagram.
Use words from the box to complete the sentences.
covalent giant low smal
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l
four high six weak
One reason for using silica to make bricks for high-temperature furnaces is that silica has a
.......................................... melting point.
Silica has this property because it is a .......................................... structure in which each silicon
atom is joined to .......................................... oxygen atoms by ..........................................
bonds. (Total 4 marks)
Q26. Pieces of zinc react with dilute acid to form hydrogen gas.
The graph shows how the volume of hydrogen gas produced changes with time.
(a) Describe, as fully as you can, how the volume of gas produced changes with time.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
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(2)
(b) A student wants to make the reaction take place faster.
Some suggestions are given in the table.
Put ticks ( ) next to the two suggestions that would make the reaction take place faster.
Suggestions ( )
Use bigger pieces of zinc.
Use a more concentrated acid.
Use zinc powder.
Decrease the temperature of the acid.
(2) (Total 4 marks)
Q27. This label was taken from a cola drink.
The pH of this drink is 2.5.
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(a) (i) Which one of the ingredients in the cola drink causes the low pH?
.......................................................................................................................... (1)
(ii) Draw a ring around the name of the ion that gives the cola drink its low pH.
chloride hydrogen hydroxide sodium (1)
(b) The preservative used in the cola drink is sodium benzoate. Sodium benzoate is made using two chemical reactions.
Reaction 1 Methylbenzene is reacted with oxygen, with the help of a catalyst, to form benzoic
acid.
Reaction 2 Benzoic acid is neutralised by sodium hydroxide solution to form sodium benzoate
and water.
(i) How does the catalyst help reaction 1?
..........................................................................................................................
.......................................................................................................................... (1)
(ii) Reaction 1 has a high atom economy.
The table lists several statements. Put a tick ( ) next to the one statement which best describes a high atom economy.
Statement ( )
All the atoms used are cheap.
Most of the starting materials end up as useful products.
Only a small number of atoms are used in the reaction.
(1)
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(iii) Reaction 2 is a neutralisation reaction.
Complete the equation by writing the formula of the product.
H+ + OH– → ................... (1)
(Total 5 marks)
Q28. The electrolysis of sodium chloride solution produces useful substances.
(a) (i) Choose a word from the box to complete the sentence.
covalent ionic non-metallic
Electrolysis takes place when electricity passes through ..................................
compounds when they are molten or in solution. (1)
(ii) Choose a word from the box to complete the sentence.
alkenes elements salts
During electrolysis the compound is broken down to form............................... (1)
(b) The table of ions on the Data Sheet may help you to answer this question.
The diagram shows an apparatus used for the electrolysis of sodium chloride solution.
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Reproduced with the permission of Nelson Thornes Ltd from PATRICK FULLICK et al, ISBN 0-7487-9644- 4. First published in 2006
Identify the products A, B and C on the diagram using substances from the box.
chlorine gas hydrogen gas oxygen gas
sodium hydroxide solution sodium metal
(i) A is .................................................................................................................... (1)
(ii) B is .................................................................................................................... (1)
(iii) C is .................................................................................................................... (1)
(Total 5 marks)
Q29. Distress flares are used to attract attention in an emergency.
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Flares often contain magnesium. Magnesium burns to form magnesium oxide.
(a) The distress flare burns with a bright flame because the reaction is very exothermic.
Complete the following sentence using the correct words from the box.
gives out heat stores heat takes in heat
An exothermic reaction is one which .......................................................................... (1)
(b) The diagram shows the electronic structure of a magnesium atom. The atomic (proton) number of magnesium is 12.
Magnesium atom
The atomic (proton) number of oxygen is 8.
Which diagram, A, B, C or D, shows the electronic structure of an oxygen atom?
Diagram .............................. (1)
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(c) Magnesium ions and oxide ions are formed when magnesium reacts with oxygen. The diagram shows the electronic structure of an oxide ion.
Oxide ion
Which diagram, J, K, L or M, shows the electronic structure of a magnesium ion?
Diagram .............................. (1)
(d) Indigestion tablets can be made from magnesium oxide. The magnesium oxide neutralises some of the hydrochloric acid in the stomach.
Draw a ring around the name of the salt formed when magnesium oxide reacts with hydrochloric acid.
magnesium chloride magnesium hydroxide magnesium sulfate (1)
(Total 4 marks)
Q30. This question is about giant structures. Diamond, graphite and silicon dioxide all have giant structures.
(a) The diagrams show the structures of these three substances.
Draw a line from each structure to its name.
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(2)
(b) Complete the sentences using words from the box.
covalent four hard ionic
shiny soft three two
(i) Diamond, graphite and silicon dioxide have high melting points because all the
atoms in their structures are joined by strong ............................................... bonds.
(1)
(ii) In diamond each atom is joined to ............................................... other atoms. (1)
(iii) Diamond can be used to make cutting tools because it has a rigid structure which
makes it very ................................................ (1)
(iv) In graphite each atom is joined to ............................................... other atoms. (1)
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(v) Graphite can be used to make pencils because it has a structure which makes it
................................................ (1)
(c) When a diamond is heated to a high temperature and then placed in pure oxygen it burns. Carbon dioxide is the only product.
Name the element in diamond. ................................................................................... (1)
(Total 8 marks)
Q31. The diagram represents a particle of methane.
(a) What is the formula of methane? ............................................................................... (1)
(b) Choose a word from the box to answer the question.
atom ion molecule
Which of the words best describes the methane particle shown in the diagram?
................................................. (1)
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(c) Choose a word from the box to answer the question.
covalent ionic metallic
What is the type of bonding shown in the diagram?
.................................................. (1)
(Total 3 marks)
Q32. Chromatography was carried out on a sample of soft drinks to check that they contained only colours that were safe. This is the result.
Safe colours Colours from the soft drinks
What conclusions about the safety of the colours in the soft drinks A, B, C and D can be made from the results shown by chromatography?
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
............................................................................................................................................... (Total 2 marks)
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Q33. Read the article and then answer the questions that follow.
Hydrogen fuel for cars?
Hydrogen is an excellent fuel. On combustion it reacts with oxygen from the air to release a large amount of energy. The only product of combustion is water which does not cause pollution. Hydrogen gas can be stored under pressure in a cylinder but a leak of the gas could cause an explosion.
It has been found that lithium nitride can absorb and then release large volumes of hydrogen. Hydrogen stored in lithium nitride will not explode.
The problem is that the rate at which hydrogen is absorbed and then released from normal sized particles of lithium nitride is slow.
Recently scientists have made ‘nanosized’ particles of lithium nitride. The ‘nanosized’ particles have the advantage that they absorb and release the hydrogen much faster when needed in the fuel cell.
(a) Use information from the article to help you to answer these questions.
(i) Give two reasons why hydrogen is an excellent fuel.
1 .........................................................................................................................
...........................................................................................................................
2 .........................................................................................................................
........................................................................................................................... (2)
(ii) Hydrogen stored in lithium nitride is safer in an accident than a cylinder full of hydrogen gas.
State why.
...........................................................................................................................
........................................................................................................................... (1)
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(iii) What is the advantage of using ‘nanosized’ particles of lithium nitride instead of normal sized particles for storing hydrogen?
...........................................................................................................................
........................................................................................................................... (1)
(b) Lithium nitride is an ionic compound that contains lithium ions (Li+) and nitride ions (N3–).
(i) The periodic table on the Data Sheet may help you to answer this question.
Which diagram, A, B or C, represents the electronic structure of a lithium atom? Write your answer in the box.
Diagram (1)
(ii) Tick ( ) the statement which describes how a lithium atom (Li) changes into a lithium ion (Li+).
Statement Tick ( )
A lithium atom loses a neutron.
A lithium atom loses an electron.
A lithium atom loses a proton.
(1)
(iii) The diagram shows the electronic structure of a nitrogen atom.
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Which diagram, A, B or C, represents the electronic structure of a nitride ion (N3–)? Write your answer in the box.
Diagram (1)
(c) The equation for the reaction of lithium nitride with hydrogen is:
Li3N + 2H2 LiNH2 + 2LiH
What does the symbol mean?
Draw a ring around your answer.
reversible reaction endothermic reaction neutralisation (1)
(d) Draw a ring around the correct answer in each box to complete the sentences.
(i) ‘Nanosized’ particles of lithium nitride will be
much larger
a little larger
much smaller
than normal sized particles of lithium nitride. (1)
(ii) One of the reasons why ‘nanosized’ particles have different properties
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from normal sized particles is that they have a greater
density
mass
surface area
than normal sized particles of lithium nitride. (1)
(Total 10 marks)
Q34. This drill contains an electric motor.
The diagram below shows the main parts of an electric motor.
The carbon contacts are made of graphite. Springs push the contacts against the copper ring. The carbon contacts conduct electricity to the copper ring. The copper ring rotates rapidly but does not stick or become worn because the graphite is soft and slippery.
(a) Using this information give two properties that make graphite suitable for making the carbon contacts.
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1 ...................................................................................................................................
.....................................................................................................................................
2 ...................................................................................................................................
..................................................................................................................................... (2)
(b) (i) Draw a ring around the correct word in each box to complete the sentence.
Each carbon atom in graphite is joined to
two
three
four
other carbon atoms by
covalent
ionic
metallic
bonds.
(2)
(ii) Tick ( ) the statement which explains why graphite is soft and slippery.
Statement Tick ( )
It is made of layers of atoms.
It is made of small molecules.
It is an ionic compound.
(1) (Total 5 marks)
Q35. This drill contains an electric motor.
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The diagram below shows the main parts of an electric motor.
The carbon contacts are made of graphite. Springs push the contacts against the copper ring. The carbon contacts conduct electricity to the copper ring. The copper ring rotates rapidly but does not stick or become worn because the graphite is soft and slippery.
(a) Using this information give two properties that make graphite suitable for making the carbon contacts.
1 ...................................................................................................................................
.....................................................................................................................................
2 ...................................................................................................................................
..................................................................................................................................... (2)
(b) (i) Draw a ring around the correct word in each box to complete the sentence.
Each carbon atom in graphite is joined to
two
three
other carbon atoms by
covalent
ionic
bonds.
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four metallic
(2)
(ii) Tick ( ) the statement which explains why graphite is soft and slippery.
Statement Tick ( )
It is made of layers of atoms.
It is made of small molecules.
It is an ionic compound.
(1) (Total 5 marks)
