1. Paper 1 Chemistry Exam questions and markschemes to project

2. Exam Question
1. Fossil fuels contain carbon and hydrogen. 1 (a) (i) Use the Chemistry Data Sheet to help you to answer this question. Complete Figure 1 to show the electronic structure of a carbon atom. Figure 1 1 (a) (ii) Complete the word equation for the oxidation of hydrogen. hydrogen + oxygen

3. 1 (b) The diagram represents a magnesium atom.
Complete the table to show the name of each particle and the charge of each particle in
the magnesium atom (2 marks)
Name of particle
Charge
proton +1
neutron
______
_____________ -1
1 (c) Use the Chemistry Data Sheet to help you to answer these questions.
Draw a ring around the correct answer to complete each sentence.
1 (c) (i) In a magnesium atom, the protons and neutrons are in the
Core nucleus shell (1 mark)
1 (c) (ii) The number of protons in a magnesium atom is the
atomic number mass number group number (1 mark)
1 (c) (iii) The sum of the protons and neutrons in a magnesium atom is the
atomic number mass number group number (1 mark)

4. Exam Question - Answers
1. Fossil fuels contain carbon and hydrogen. 1 (a) (i) Use the Chemistry Data Sheet to help you to answer this question. Complete Figure 1 to show the electronic structure of a carbon atom. Figure 1 1 mark 1 (a) (ii) Complete the word equation for the oxidation of hydrogen. hydrogen + oxygen hydrogen oxide or water x x x x x x

5. 1 (b) The diagram represents a magnesium atom.
Complete the table to show the name of each particle and the charge of each particle in
the magnesium atom (2 marks)
Name of particle
Charge
proton +1
neutron
___0___
_electron__ -1
1 (c) Use the Chemistry Data Sheet to help you to answer these questions.
Draw a ring around the correct answer to complete each sentence.
1 (c) (i) In a magnesium atom, the protons and neutrons are in the
Core nucleus shell (1 mark)
1 (c) (ii) The number of protons in a magnesium atom is the
atomic number mass number group number (1 mark)
1 (c) (iii) The sum of the protons and neutrons in a magnesium atom is the
atomic number mass number group number (1 mark)

6. 7 Glass is made from silicon dioxide.
7 (a) Silicon dioxide has a very high melting point.
Other substances are added to silicon dioxide to make glass. Glass melts at a lower temperature than silicon dioxide. Suggest why.
[1 mark]
7 (b) Sodium oxide is one of the substances added to silicon dioxide to make glass.
7 (b) (i) Sodium oxide contains Na+ ions and O2– ions.
Give the formula of sodium oxide [1 mark]

7. 7 (b) (ii) Sodium oxide is made by heating sodium metal in oxygen gas.
Complete the diagram to show the outer electrons in an oxygen molecule (O2).
[2 marks]
7 (c) Glass can be coloured using tiny particles of gold. Gold is a metal.
Describe the structure of a metal.
[3 marks]

8. 5 Carbon atoms are used to make nanotubes.
Carbon atoms in a nanotube are bonded like a single layer of graphite.
The diagram below shows the structure of a single layer of graphite.
5 (a) Suggest why carbon nanotubes are used as lubricants [2 marks]
5 (b) Explain why graphite can conduct electricity [2 marks]

9. 4 (b) Magnesium can be produced from magnesium oxide.
The equation for the reaction is:
Si(s) + 2 MgO(s) SiO2(s) + 2 Mg(g)
4 (b) (i) How can you tell from the equation that the reaction is done at a high temperature? [1 mark]
4 (b) (ii) This reaction to produce magnesium from magnesium oxide is endothermic.
What is meant by an endothermic reaction? [1 mark]
4 (b) (iii) A company made magnesium using this reaction.
Calculate the mass of magnesium oxide needed to produce 1.2 tonnes of magnesium.
Relative atomic masses (Ar): O = 16; Mg = [3 marks]
Mass of magnesium oxide needed = Tonnes
4 (b) (iv) The company calculated that they would produce 1.2 tonnes of magnesium, but only 0.9 tonnes was produced. Calculate the percentage yield [1 mark]
Percentage yield = %
4 (b) (v) Give one reason why the calculated yield of magnesium might not be obtained [1 mark]

10. 5 Titanium is as strong as steel but is much more expensive
5 Titanium is as strong as steel but is much more expensive. It is used to make jet engines for aircraft and to make replacement hip joints for people.
a Give two properties that make titanium better than steel for making jet engines and replacement hip joints (2 marks)
b In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Titanium is made in batches of about 10 tonnes that takes up to 15 days. The main steps to make titanium are:
Titanium oxide is reacted with chlorine to produce titanium chloride.
Titanium chloride is reacted with magnesium at 900°C in a sealed reactor for three days to give a mixture of titanium and magnesium chloride.
The reactor is cooled for 7 days, and then the mixture is removed.
The magnesium chloride is removed from the mixture by distillation at very low pressure.
The titanium is melted in an electric furnace and poured into moulds.
Steel is produced at about 8000 tonnes per day. The main steps to make steel are:
Iron oxide is reacted with carbon (coke) in a blast furnace that runs continuously.
The molten impure iron flows to the bottom of the furnace and is removed every four hours.
Oxygen is blown into the molten iron for about 20 minutes to produce steel.
The steel is poured into moulds.
Explain why titanium costs more than steel (6 marks)

11. 5 Titanium is as strong as steel but is much more expensive
5 Titanium is as strong as steel but is much more expensive. It is used to make jet engines for aircraft and to make replacement hip joints for people.
a Give two properties that make titanium better than steel for making jet engines and replacement hip joints. Resistant to corrosion; light;strong (2 marks)
b In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Explain why titanium costs more than steel (6 marks)
Titanium – batch process; 10 tonnes takes 15 days to produce; many stages in manufacture; heated up, cooled down then reheated uses lots of energy; long manufacture – left for 7 days at one point; purification step (distillation) required; further heating by expensive electrical proces and finally poured into moulds; labour intensive
Steel – continuous process making 8000 tonnes per day; cheap raw materials, few processes involved; fewer steps in process, less energy intensive, less labour intensive
Needs to be continuous prose or bullet points with substantial sentences to get the QWC marks

12. 4 Where copper ore has been mined there are areas of land that contain very low
percentages of copper compounds. One way to extract the copper is to grow plants on the land. The plants absorb copper compounds through their roots.
The plants are burned to produce copper oxide. The copper oxide produced from plants can be reacted to produce copper or copper sulfate solution, as shown below:
4 (a) (i) Complete the sentence [1 mark]
Using plants to extract metals is called ________________________________ .
4 (a) (ii) Suggest two reasons why copper from these areas of land is not extracted by smelting [2 marks]
4 (a) (iii) Complete and balance the chemical equation for the reaction of copper oxide with carbon [2 marks]
CuO + C CO2
4 (b) Copper is produced from copper sulfate solution by displacement using scrap iron or
by electrolysis.
4 (b) (i) Use the Chemistry Data Sheet to help you to answer this question.
Give two reasons why scrap iron is used to displace copper [2 marks]
Add carbon and heat
Copper
Copper oxide
Produced from plants
Add sulfuric acid
Copper sulfate solution

13. 4 Where copper ore has been mined there are areas of land that contain very low
percentages of copper compounds. One way to extract the copper is to grow plants on the land. The plants absorb copper compounds through their roots.
The plants are burned to produce copper oxide. The copper oxide produced from plants can be reacted to produce copper or copper sulfate solution, as shown below:
4 (a) (i) Complete the sentence [1 mark]
Using plants to extract metals is called _____phytomining___________________________ .
4 (a) (ii) Suggest two reasons why copper from these areas of land is not extracted by smelting. Low quality ore – not much copper in it; uneconomic as needs lots of processing so expensive [2 marks]
4 (a) (iii) Complete and balance the chemical equation for the reaction of copper oxide with carbon [2 marks]
CuO + C Cu CO2
4 (b) Copper is produced from copper sulfate solution by displacement using scrap iron or
by electrolysis.
4 (b) (i) Use the Chemistry Data Sheet to help you to answer this question.
Give two reasons why scrap iron is used to displace copper. Iron more reactive than copper; iron cheaper than copper [2 marks]
Add carbon and heat
Copper
Copper oxide
Produced from plants
Add sulfuric acid
Copper sulfate solution

14. 4 (b) (ii) Figure 4 shows the electrolysis of copper sulfate solution.
Describe what happens to the copper ions during electrolysis.
Books page 164/ [2 marks]

15. 4 (b) (ii) Figure 4 shows the electrolysis of copper sulfate solution.
Describe what happens to the copper ions during electrolysis [2 marks]
Copper ions are attracted to the negative electrode; pick-up two electrons (or are reduced) to form copper atoms; copper metal deposited on negative electrode

16. 1 The label shows the ingredients in a drink called Cola.
Carbonated water
Sugar
Colouring
Phosphoric acid
Flavouring
Caffeine
1 (a) (i) The pH of carbonated water is 4.5.
The pH of Cola is 2.9.
Name the ingredient on the label that lowers the pH of Cola to [1 mark]
1 (a) (ii) Which ion causes the pH to be 2.9? [1 mark]

25. Past paper question (AS)

26. Mark scheme

27. 4 This question is about zinc and magnesium.
Zinc is produced by electrolysis of molten zinc chloride, as shown below:
4 (a) (i) Why must the zinc chloride be molten for electrolysis? [1 mark]
4 (a) (ii) Describe what happens at the negative electrode [3 marks]
4 (a) (iii) Complete the half equation for the reaction at the positive electrode.
[1 mark]
Cl e–
d.c. power
supply
Molten zinc
chloride