Cambridge IGCSE Chemistry 0620 Paper 2 Extended Multiple Choice Sample 2022
This sample paper replicates the real extended-tier multiple-choice challenge that separates a grade 7 from a grade 9 in Chemistry, testing not just what you know but how you apply it under pressure. You'll face 20 questions spanning atomic structure, bonding, moles, electrochemistry, kinetics, and organic chemistry—the same syllabus domains that appear in every IGCSE Chemistry paper since the curriculum reformed. The questions are styled exactly as the real board writes them: some require formula recall, others demand reasoning through novel scenarios, and a few are designed to catch out students who confuse similar concepts. By the time you finish this paper, you'll know which topic areas still need drilling and be able to spot the trick in a mark-scheme answer before it's explained to you.
Questions in this quiz
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- Question 1
An atom has the electron configuration 2, 8, 7. What is the atomic number and which group of the periodic table does this atom belong to?
- Question 2
Magnesium oxide (MgO) has a very high melting point of 2852°C and is insoluble in water. Which of the following best explains these properties?
- Question 3
True or False: A substance that conducts electricity only when melted or dissolved in water must be an ionic compound.
- Question 4
Calculate the relative formula mass of calcium carbonate (CaCO₃). (Ar: Ca = 40, C = 12, O = 16)
- Question 5
When 12.5 g of calcium carbonate undergoes thermal decomposition according to the equation CaCO₃ → CaO + CO₂, what mass of calcium oxide (CaO) is produced? (Relative atomic masses: Ca = 40, C = 12, O = 16; Mr(CaCO₃) = 100, Mr(CaO) = 56)
- Question 6
During the electrolysis of molten potassium chloride (KCl), which products form at the electrodes?
- Question 7
A reaction has a high activation energy but is exothermic overall. Which statement is correct?
- Question 8
Which of the following increases the rate of a chemical reaction?
- Question 9
At equilibrium, the forward and backward reaction rates are equal. True or False: The concentrations of reactants and products must also be equal.
- Question 10
The equilibrium system is: 2NO₂(g) ⇌ N₂O₄(g), which is colourless. The system is at equilibrium with a brown gas colour (due to NO₂). What colour change is observed if the pressure is increased at constant temperature?
- Question 11
Which of the following is a saturated hydrocarbon with the molecular formula C₅H₁₂?
- Question 12
When ethene (C₂H₄) reacts with bromine water, the colour of the bromine water changes from orange-brown to colourless. What type of reaction is this?
- Question 13
Ethanol (C₂H₅OH) can be oxidised by acidified potassium dichromate. What is the main organic product?
- Question 14
A polymer is formed by linking together many molecules of ethene. What is the name of this polymer and what type of polymerisation reaction occurs?
- Question 15
Sodium is more reactive than magnesium. Which statement best explains this in terms of atomic structure?
- Question 16
Iron can be extracted from iron ore by reducing iron oxide with carbon monoxide in a blast furnace. The equation is: Fe₂O₃ + 3CO → 2Fe + 3CO₂. If 160 g of iron oxide is reacted, what mass of iron is produced? (Relative atomic masses: Fe = 56, O = 16, C = 12; Mr(Fe₂O₃) = 160, Mr(Fe) = 56)
- Question 17
Acid rain is formed when sulfur dioxide (SO₂) released from burning fossil fuels dissolves in rainwater. What product is formed when SO₂ dissolves in water?
- Question 18
Which of the following compounds is amphoteric and can react with both an acid and a base?
- Question 19
Complete the statement: In the reaction 2H₂ + O₂ → 2H₂O, the ratio of moles of hydrogen gas to water molecules is ___.
- Question 20
Copper can be extracted from copper sulfide (Cu₂S) by roasting (heating in air) to form copper oxide, then reducing with carbon. What is the balanced equation for the reduction of copper oxide by carbon?