Total marks: 60 · Duration: 1 hour 15 minutes
Instructions to candidates
- This paper has 60 questions. Answer ALL questions.
- Each question is worth ONE mark.
- For each question there are four options, A, B, C and D. Choose the ONE you think is correct. In the January 2027 sitting, Paper 01 is taken online, so you select your answer on screen.
- The questions are grouped by syllabus section: Principles of Chemistry (1–32), Organic Chemistry (33–44) and Inorganic Chemistry (45–60).
- You may use a silent, non-programmable electronic calculator.
- Relative atomic masses: H = 1, C = 12, O = 16, Na = 23, Mg = 24, Cl = 35.5, Ag = 108.
- One mole of any gas occupies 24 dm³ at room temperature and pressure. 1 faraday = 96 500 C.
Paper
Section A — Principles of Chemistry
1. Which of the following is a mixture?
A) Water
B) Air
C) Carbon dioxide
D) Sodium chloride
2. A student has a mixture of salt and sand. Which sequence separates the salt?
A) Add water, filter, then evaporate the filtrate
B) Evaporate, add water, then filter the solution
C) Distil the mixture, then filter the distillate
D) Filter, add water, then evaporate the residue
3. In a chromatogram, a dye spot moves 3.0 cm while the solvent front moves 7.5 cm. What is the Rf value of the dye?
A) 2.5
B) 0.25
C) 0.4
D) 4.5
4. Which observation shows that a solid is a pure substance?
A) It melts sharply at a fixed temperature
B) It dissolves completely in water
C) It melts over a range of temperatures
D) It has a bright, shiny appearance
5. An atom of aluminium has atomic number 13 and mass number 27. How many neutrons does it have?
A) 40
B) 27
C) 14
D) 13
6. How many electrons are there in a magnesium ion, Mg²⁺? (Atomic number of Mg = 12)
A) 14
B) 12
C) 10
D) 2
7. Boron consists of 20% boron-10 and 80% boron-11. What is its relative atomic mass?
A) 10.8
B) 11.0
C) 10.5
D) 10.2
8. An element is in Group II and Period 3 of the Periodic Table. What is its electron configuration?
A) 2, 8, 3
B) 2, 3
C) 2, 2, 8
D) 2, 8, 2
9. Which pair of elements would combine to form a covalent compound?
A) Calcium and oxygen
B) Potassium and bromine
C) Carbon and chlorine
D) Sodium and chlorine
10. How many pairs of electrons are shared in one molecule of carbon dioxide, O=C=O?
A) 6
B) 2
C) 4
D) 8
11. Metallic bonding is best described as
A) positive ions in a sea of delocalised electrons
B) atoms sharing pairs of electrons in molecules
C) neutral atoms held by weak forces
D) negative ions held between positive ions
12. Diamond is used in cutting tools because each carbon atom
A) is held in layers that slide easily
B) is covalently bonded to four others in a rigid lattice
C) forms ionic bonds with its neighbours
D) has one free electron that can move
13. What is the formula of sodium sulfate?
A) Na(SO₄)₂
B) Na₂SO₄
C) NaSO₄
D) Na₂SO₃
14. What is the relative formula mass of magnesium hydroxide, Mg(OH)₂?
A) 82
B) 42
C) 41
D) 58
15. How many moles are there in 11 g of carbon dioxide, CO₂?
A) 0.11
B) 0.5
C) 0.25
D) 4
16. What volume does 3.2 g of oxygen gas, O₂, occupy at room temperature and pressure?
A) 2.4 dm³
B) 4.8 dm³
C) 76.8 dm³
D) 1.2 dm³
17. What is the percentage by mass of oxygen in water, H₂O?
A) 11.1%
B) 50.0%
C) 33.3%
D) 88.9%
18. Magnesium burns in oxygen: 2Mg + O₂ → 2MgO. What mass of magnesium oxide forms from 6 g of magnesium?
A) 6 g
B) 10 g
C) 5 g
D) 20 g
19. 5.85 g of sodium chloride (Mr = 58.5) is dissolved to make 500 cm³ of solution. What is its concentration?
A) 0.2 mol/dm³
B) 0.1 mol/dm³
C) 11.7 mol/dm³
D) 0.05 mol/dm³
20. In the equation __Al + __O₂ → 2Al₂O₃, which numbers balance it?
A) 2 and 3
B) 4 and 3
C) 2 and 2
D) 4 and 6
21. Ethanoic acid is described as a weak acid because it
A) is only partly ionised in water
B) has a low concentration
C) contains no hydrogen ions
D) does not react with metals
22. Copper(II) oxide is warmed with dilute sulfuric acid. What are the products?
A) Copper and sulfur dioxide
B) Copper(II) sulfate and hydrogen
C) Copper(II) sulfate and water
D) Copper(II) hydroxide and oxygen
23. 20.0 cm³ of 0.10 mol/dm³ hydrochloric acid exactly neutralises 25.0 cm³ of sodium hydroxide solution. What is the concentration of the sodium hydroxide?
A) 0.10 mol/dm³
B) 0.125 mol/dm³
C) 0.08 mol/dm³
D) 0.002 mol/dm³
24. Which method is used to prepare copper(II) sulfate crystals from copper(II) oxide and dilute sulfuric acid?
A) Add excess oxide to warm acid, filter, then crystallise the filtrate
B) Mix two solutions and filter off the precipitate
C) Heat the copper oxide strongly until it melts
D) Titrate the acid with copper oxide solution
25. In terms of oxygen, reduction is
A) the loss of oxygen
B) the gain of electrons and oxygen
C) the gain of oxygen
D) the loss of hydrogen
26. What is the oxidation number of manganese in potassium manganate(VII), KMnO₄?
A) −7
B) +7
C) +2
D) +4
27. Raising the temperature increases the rate of a reaction MAINLY because the particles
A) change into a catalyst at higher temperatures
B) lose energy, so they stick together more
C) become larger, so they collide more often
D) have more energy, so more collisions exceed the activation energy
28. When ammonium nitrate dissolves in water, the temperature of the water falls. This dissolving is
A) a neutralisation
B) endothermic
C) exothermic
D) a combustion
29. A reaction raises the temperature of 50 cm³ of water by 6 °C. Taking the specific heat capacity of water as 4.2 J/g/°C and 1 cm³ of water as 1 g, how much heat was released?
A) 12 600 J
B) 300 J
C) 210 J
D) 1260 J
30. Concentrated sodium chloride solution (brine) is electrolysed with inert electrodes. What forms at the anode?
A) Sodium
B) Chlorine
C) Oxygen
D) Hydrogen
31. A spoon is to be electroplated with silver. Where must the spoon be placed?
A) As the anode, in pure water
B) As the anode, in a solution of a silver salt
C) As the cathode, in a solution of copper sulfate
D) As the cathode, in a solution of a silver salt
32. How much silver is deposited when 0.5 faraday passes through silver nitrate solution? (Ag⁺ + e⁻ → Ag)
A) 108 g
B) 27 g
C) 54 g
D) 216 g
Section B — Organic Chemistry
33. Members of a homologous series have
A) the same molecular formula and boiling point
B) the same number of carbon atoms
C) identical physical properties
D) the same general formula and similar chemical properties
34. What is the name of the alkane C₃H₈?
A) Propene
B) Butane
C) Propane
D) Ethane
35. How many structural isomers does butane, C₄H₁₀, have?
A) 3
B) 4
C) 2
D) 1
36. Methane reacts with chlorine in ultraviolet light. What type of reaction is this?
A) Polymerisation
B) Substitution
C) Neutralisation
D) Addition
37. Ethene is bubbled into bromine water. What colour change is seen?
A) Orange to colourless
B) Blue to green
C) Colourless to orange
D) Purple to colourless
38. Ethanol is warmed with acidified potassium dichromate(VI). What is formed, and what colour change is seen?
A) Ethyl ethanoate; orange to colourless
B) Ethanoic acid; orange to green
C) Ethene; green to orange
D) Carbon dioxide; purple to colourless
39. Esters are used in perfumes and flavourings MAINLY because they
A) have pleasant, fruity smells
B) are strong acids
C) do not evaporate
D) are good conductors
40. Why are soapless detergents better than soap in hard water?
A) They contain more calcium and magnesium ions
B) They remove the water from the clothes
C) They react with the dirt to form a gas
D) They do not form scum with calcium and magnesium ions
41. Nylon is a polyamide. Which natural polymer has the same type of linkage?
A) Natural rubber
B) Starch
C) Protein
D) Cellulose
42. Which toxic gas forms when a hydrocarbon burns in a limited supply of air?
A) Carbon monoxide
B) Hydrogen
C) Ozone
D) Carbon dioxide
43. Which conditions are needed for the fermentation of glucose to ethanol?
A) Yeast, about 30 °C and no air
B) Ultraviolet light and chlorine
C) A nickel catalyst, 60 °C and hydrogen
D) Concentrated acid and 300 °C
44. Which functional group do all alcohols contain?
A) –COO–
B) C=C
C) –COOH
D) –OH
Section C — Inorganic Chemistry
45. Which metal reacts violently with cold water, producing hydrogen and an alkaline solution?
A) Zinc
B) Iron
C) Copper
D) Potassium
46. Magnesium ribbon is placed in zinc sulfate solution. What happens?
A) Magnesium is deposited, because zinc is more reactive
B) No reaction, because zinc is more reactive
C) Zinc is deposited, because magnesium is more reactive
D) Hydrogen is released, because magnesium is an acid
47. Iron is extracted from its oxide by heating with carbon, but aluminium is not. Why?
A) Aluminium oxide does not contain any oxygen
B) Carbon is more reactive than iron but less reactive than aluminium
C) Iron oxide melts at a lower temperature than carbon
D) Carbon is less reactive than iron but more reactive than aluminium
48. Aluminium is a reactive metal, yet aluminium window frames do not corrode. Why?
A) Aluminium does not react with oxygen at all
B) A thin, protective layer of aluminium oxide forms on the surface
C) Aluminium is less reactive than iron
D) Aluminium is coated with zinc during manufacture
49. Why are alloys such as brass harder than the pure metals they are made from?
A) The atoms in an alloy are joined by ionic bonds
B) Alloys are compounds with fixed formulae
C) Alloys contain no delocalised electrons
D) Atoms of different sizes stop the layers sliding over each other
50. Blocks of magnesium are attached to the steel hull of a ship. How does this prevent rusting?
A) Magnesium forms a waterproof paint over the hull
B) Magnesium is more reactive, so it corrodes instead of the iron
C) Magnesium makes the sea water less salty
D) Magnesium reacts with rust and turns it back into iron
51. Which test identifies oxygen gas?
A) It gives a squeaky pop with a lighted splint
B) It bleaches damp litmus paper
C) It turns limewater milky
D) It relights a glowing splint
52. Which test identifies chlorine gas?
A) It bleaches damp litmus paper
B) It turns limewater milky
C) It relights a glowing splint
D) It turns damp red litmus blue
53. A white solid is warmed with sodium hydroxide solution, and a gas that turns damp red litmus blue is given off. Which ion is present in the solid?
A) Chloride, Cl⁻
B) Ammonium, NH₄⁺
C) Carbonate, CO₃²⁻
D) Sulfate, SO₄²⁻
54. Dilute hydrochloric acid is added to a solid, and the gas given off turns limewater milky. Which ion is present?
A) Carbonate, CO₃²⁻
B) Nitrate, NO₃⁻
C) Sulfate, SO₄²⁻
D) Chloride, Cl⁻
55. Sodium hydroxide solution is added to a solution, giving a white precipitate that dissolves in excess. Which ion could be present?
A) Calcium, Ca²⁺
B) Iron(II), Fe²⁺
C) Zinc, Zn²⁺
D) Copper(II), Cu²⁺
56. Sodium hydroxide solution is added to a solution containing iron(II) ions. What colour is the precipitate?
A) Red-brown
B) White
C) Green
D) Blue
57. Fertilisers washed from fields into a lake can lead to fish deaths. What is this process called?
A) Neutralisation
B) Electrolysis
C) Fermentation
D) Eutrophication
58. Hard water contains dissolved
A) oxygen and nitrogen gases
B) calcium and magnesium ions
C) chloride and nitrate ions
D) sodium and potassium ions
59. Which gas released by burning fossil fuels is MAINLY responsible for the enhanced greenhouse effect?
A) Carbon monoxide
B) Nitrogen
C) Sulfur dioxide
D) Carbon dioxide
60. Aluminium is used for overhead power cables rather than copper MAINLY because it
A) is a better conductor than copper
B) is more reactive, so it corrodes quickly
C) is magnetic, so it holds the current
D) has a low density and conducts electricity well