How does the reactivity series let us predict the reactions of metals?
The reactivity series of metals, the reactions of metals with water, oxygen and acids, displacement reactions, and using the reactivity series to predict reactions.
A focused answer to OCR Gateway GCSE Chemistry A topic C4.1 on the reactivity series, covering the order of metal reactivity, the reactions of metals with water, oxygen and acids, displacement reactions, and using the series to predict whether a reaction will happen.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
Jump to a section
What this dot point is asking
OCR wants you to know the reactivity series of metals, describe the reactions of metals with water, oxygen and acids, explain displacement reactions, and use the reactivity series to predict whether a reaction will happen. This underpins metal extraction and links to redox.
The reactivity series
The higher a metal is in the series, the more readily it loses electrons to form positive ions, and the more vigorously it reacts.
Reactions with water and oxygen
Reactions with acids
Metals above hydrogen in the reactivity series react with dilute acids to give a salt and hydrogen. The more reactive the metal, the faster the reaction (more vigorous fizzing). For example, magnesium reacts faster than zinc, which reacts faster than iron. Metals below hydrogen (copper, silver, gold) do not react with dilute acids. The hydrogen produced gives a squeaky pop with a lighted splint.
Displacement reactions
Displacement reactions are redox reactions: the more reactive metal is oxidised (loses electrons) and the less reactive metal ion is reduced (gains electrons).
Predicting reactions
To predict whether a reaction will happen, compare the positions of the metals in the reactivity series:
- A metal higher in the series will displace one lower in the series from its salt solution or oxide.
- A metal lower in the series will not displace one higher up, so no reaction occurs.
The bigger the gap in reactivity, the more vigorous the reaction tends to be.
Exam-style practice questions
Practice questions written in the style of OCR exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
OCR 20184 marksUsing the reactivity series, predict whether each of these reactions will happen and explain your reasoning: (a) zinc added to copper sulfate solution, (b) copper added to zinc sulfate solution.Show worked answer →
A C4.1 displacement question. Reward: (a) zinc is more reactive than copper, so zinc will displace copper from copper sulfate solution; the reaction happens, forming zinc sulfate and copper. (b) copper is less reactive than zinc, so copper cannot displace zinc from zinc sulfate solution; no reaction happens. The rule is that a more reactive metal displaces a less reactive metal from a solution of its salt. Markers credit the prediction that (a) reacts because zinc is more reactive, and (b) does not react because copper is less reactive, with reasoning based on the reactivity series. A common error is to say both react or to reverse the reactivity order.
OCR 20214 marksDescribe what you would observe when a small piece of potassium and a small piece of calcium are each added to water, and explain the difference using the reactivity series.Show worked answer →
A Higher tier observation question. Reward: potassium reacts very vigorously with water: it fizzes rapidly, melts into a ball, moves quickly across the surface, and the hydrogen produced ignites with a lilac flame. Calcium reacts less vigorously: it sinks then fizzes steadily as bubbles of hydrogen form, and the mixture warms up, but there is no flame. The difference is because potassium is higher in the reactivity series (more reactive) than calcium, so potassium reacts faster and more violently with water. Markers credit a vigorous reaction with a flame for potassium, a steadier fizzing reaction for calcium, and the explanation that potassium is more reactive than calcium. Both produce a metal hydroxide and hydrogen.
Related dot points
- Metal ores and oxidation, extracting metals by reduction with carbon, extracting reactive metals by electrolysis, the position of carbon in the reactivity series, and predicting reactions of Group 1 and Group 7 elements.
A focused answer to OCR Gateway GCSE Chemistry A topic C4.1 on extracting metals and predicting reactions, covering metal ores, extraction by reduction with carbon, electrolysis of reactive metals, the role of carbon in the reactivity series, and predicting the reactions of Group 1 and Group 7 elements.
- Oxidation and reduction in terms of oxygen and electrons, redox reactions, oxidising and reducing agents, and writing half equations for the loss and gain of electrons.
A focused answer to OCR Gateway GCSE Chemistry A topic C3.3 on oxidation and reduction, covering the definitions in terms of oxygen and electrons, redox reactions, oxidising and reducing agents, and writing half equations for electron loss and gain.
- Electrolysis of molten and aqueous compounds, the movement of ions to the electrodes, predicting the products at the cathode and anode, half equations at the electrodes, and the extraction of reactive metals.
A focused answer to OCR Gateway GCSE Chemistry A topic C3.4 on electrolysis, covering the electrolysis of molten and aqueous compounds, the movement of ions to the electrodes, predicting the products at each electrode, half equations, and the extraction of reactive metals such as aluminium.
- The structure of the periodic table, the work of Mendeleev, metals and non-metals, and the trends in reactivity and properties of Group 1 (alkali metals), Group 7 (halogens) and Group 0 (noble gases).
A focused answer to OCR Gateway GCSE Chemistry A topic C1.3 on the periodic table, covering Mendeleev's contribution, the arrangement by atomic number, metals and non-metals, and the trends in Group 1 alkali metals, Group 7 halogens and Group 0 noble gases.
- Flame tests for metal ions, the use of sodium hydroxide to identify metal ions by precipitate colour, and the tests for hydrogen, oxygen, carbon dioxide, chlorine and ammonia.
A focused answer to OCR Gateway GCSE Chemistry A topic C4.2 on identifying substances, covering flame tests for metal ions, identifying metal ions using sodium hydroxide precipitates, and the tests for hydrogen, oxygen, carbon dioxide, chlorine and ammonia.