Reactivity Series Exam Questions
Practice IGCSE Chemistry exam questions on the reactivity series. Covers ordering metals by reactivity, predicting reactions, displacement reactions, and using the reactivity series to explain observations with mark schemes and examiner notes.
Published by IGCSEChemistry.com.my
Chemistry teaching team: K. S. Tan (15+ years teaching IGCSE Chemistry) and Ms Yash (10+ years teaching IGCSE Chemistry) and Ms Kartini (15+ years teaching IGCSE Chemistry).
Mapped to Cambridge IGCSE Chemistry 0620 (2026–2028). Last updated 2026-08-19.
These questions cover the reactivity series. Write full answers before checking.
Question 1 (2 marks, Core)
Write the reactivity series for the following metals, from most reactive to least reactive: copper, zinc, iron, magnesium, gold.
Mark scheme
Magnesium > zinc > iron > copper > gold [1] [1]
Examiner note: The full IGCSE reactivity series is: K, Na, Ca, Mg, Al, (C), Zn, Fe, (H), Cu, Ag, Au. Carbon and hydrogen are included as reference points. You must memorise this order.
Question 2 (4 marks, Core)
A student places small pieces of four metals into separate test tubes of dilute hydrochloric acid. The results are shown below.
| Metal | Observation |
|---|---|
| Magnesium | Vigorous fizzing, dissolves quickly |
| Zinc | Steady fizzing, dissolves slowly |
| Iron | Slow fizzing, very slow to dissolve |
| Copper | No reaction |
(a) Place the four metals in order of decreasing reactivity. (1)
(b) Explain why copper does not react. (1)
(c) Write the equation for the reaction of zinc with hydrochloric acid. (1)
(d) Name the gas produced and state the test for it. (1)
Mark scheme
(a) Magnesium > zinc > iron > copper [1]
(b) Copper is below hydrogen in the reactivity series, so it cannot displace hydrogen from the acid [1]
(c) Zn + 2HCl → ZnCl2 + H2 [1]
(d) Hydrogen; test with a burning splint — it burns with a squeaky pop [1]
Examiner note: Only metals above hydrogen in the reactivity series react with dilute acids. The more vigorous the reaction, the more reactive the metal. Copper, silver, and gold are below hydrogen and do not react with dilute acids.
Question 3 (4 marks, Core)
Predict whether a reaction will occur in each case. If a reaction occurs, write the equation.
(a) Iron added to copper sulfate solution. (2)
(b) Copper added to zinc sulfate solution. (2)
Mark scheme
(a) A reaction occurs — iron is more reactive than copper [1] Fe + CuSO4 → FeSO4 + Cu [1]
(b) No reaction — copper is less reactive than zinc and cannot displace it [1] [1]
Examiner note: A more reactive metal displaces a less reactive metal from its compound. Fe > Cu so iron displaces copper. Cu < Zn so copper cannot displace zinc. The observation for (a): the iron becomes coated with brown/orange copper, and the blue solution fades.
Question 4 (3 marks, Supplement)
A student adds strips of metal X, Y, and Z to solutions of the other metals’ sulfates. The results are shown below (tick = reaction, cross = no reaction).
| X sulfate | Y sulfate | Z sulfate | |
|---|---|---|---|
| Metal X | - | X | X |
| Metal Y | tick | - | X |
| Metal Z | tick | tick | - |
Place the metals in order of reactivity from most to least reactive.
Mark scheme
- Z is most reactive (displaces both X and Y) [1]
- Y is intermediate (displaces X but not Z) [1]
- X is least reactive (cannot displace Y or Z) [1]
Order: Z > Y > X
Examiner note: If a metal can displace another from solution, it is more reactive. Work systematically: Z displaces both (most reactive), X displaces neither (least reactive).
Question 5 (3 marks, Core)
When a piece of zinc is placed in copper sulfate solution, the blue colour fades and a brown deposit forms on the zinc.
(a) Explain these observations using the reactivity series. (2)
(b) Classify this reaction as displacement, decomposition, or neutralisation. (1)
Mark scheme
(a) Zinc is more reactive than copper, so zinc displaces copper from the solution [1]. The brown deposit is copper metal, and the blue colour fades because Cu2+ ions are removed from solution [1].
(b) Displacement [1]
Examiner note: The blue colour is due to Cu2+ ions. As zinc replaces copper, Cu2+ concentration decreases (colour fades) and copper metal is deposited (brown coating). Simultaneously, Zn dissolves as Zn2+ (colourless).
Question 6 (3 marks, Supplement)
Explain why the reactivity series can be used to predict the method of extraction for a metal from its ore.
Mark scheme
- Very reactive metals (above carbon) cannot be reduced by carbon and must be extracted by electrolysis [1]
- Metals below carbon in the reactivity series can be extracted by heating their ores with carbon (reduction) [1]
- Very unreactive metals (like gold) occur native / uncombined and do not need chemical extraction [1]
Examiner note: Carbon’s position in the reactivity series is the dividing line. Metals above C (K, Na, Ca, Mg, Al) need electrolysis. Metals below C (Zn, Fe, Cu) can be reduced by carbon. Gold and platinum are found as the free element.
Question 7 (3 marks, Core)
Explain why potassium reacts more vigorously with water than calcium, using the reactivity series and atomic structure.
Mark scheme
- Potassium is higher / more reactive than calcium in the reactivity series [1]
- Potassium has only one outer electron to lose (compared to two for calcium) [1]
- Potassium’s outer electron is in a higher shell / further from the nucleus with more shielding, so it is lost more easily [1]
Examiner note: Potassium (Group I, Period 4) loses its single outer electron very easily. Calcium (Group II, Period 4) must lose two electrons and they are held more tightly due to higher nuclear charge. This makes potassium the more reactive metal.
What to revise if you scored below 5
If the reactivity series order was forgotten, memorise: K Na Ca Mg Al (C) Zn Fe (H) Cu Ag Au. Use a mnemonic if it helps. If displacement predictions were difficult, remember: a more reactive metal displaces a less reactive one. Revisit the reactivity series notes.
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