2.4.3Inorganic Chemistry
Order of Reactivity — Edexcel International GCSE Science Double Award 4SD0 - Chemistry Revision Notes & Topical Questions
5 min read 10 parts Lesson 14 of 52
Part 1 of 4The reactivity series
| Position | Element | Typical behaviour |
|---|---|---|
| Most reactive | Potassium, sodium, lithium | React vigorously with cold water and acids |
| Calcium | Reacts steadily with cold water | |
| Magnesium, aluminium | React with steam and acids; aluminium is protected by an oxide layer | |
| Carbon (non-metal) | Used to extract metals below it from their oxides | |
| Zinc, iron | React slowly with steam and with acids | |
| Hydrogen (non-metal) | Dividing line between metals that do and do not react with dilute acids | |
| Copper, silver, gold | Do not react with dilute acids; found uncombined or easily reduced | |
| Least reactive | Gold | Extremely unreactive |
Part 2 of 4Remembering the order
Use a mnemonic
- Use a mnemonic A sentence whose words begin with the same letters as the metals helps recall the sequence,
- such as P, S, L, C, M, A, C, Z, I, H, C, S, G.
- Make up your own sentence; it is more memorable if it is silly.
Check with data
- Check with data If you are given experimental results, check your recalled order against them: faster bubbling or a more violent reaction means higher in the series.
Part 3 of 4What the position tells you
Position in the series
Reactions with acid
- Reactions with acid Metals above hydrogen react with dilute acids to give a salt and hydrogen;
- those below do not.
Tendency to lose electrons
- Tendency to lose electrons The higher a metal is, the more easily it forms positive ions by losing electrons.
Extraction
- Extraction Metals above carbon, such as aluminium, cannot be extracted by heating with carbon and need electrolysis.
- Metals below carbon, such as iron and zinc, can be reduced by carbon.
Displacement
- Displacement A more reactive metal displaces a less reactive metal from a solution of its salt.
Part 4 of 4Worked example
1
A piece of zinc is placed in copper(II) sulfate solution. Zinc is above copper, so it displaces it.
2
Observation: the blue solution fades and a reddish-brown solid (copper) coats the zinc.
3
Equation: Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s).
4
If the experiment were reversed, with copper in zinc sulfate, nothing would happen because copper is less reactive than zinc.
Key terms
| Term | Meaning |
|---|---|
| Reactivity | How readily a substance takes part in chemical reactions. |
| Displacement | A reaction in which a more reactive element takes the place of a less reactive one in a compound. |
| Reduction | Removal of oxygen from a compound, for example by heating a metal oxide with carbon. |
| Extraction | Obtaining a metal from its ore. |
| Ore | A rock containing enough of a metal compound to be worth extracting. |
Avoid these mistakes
1
Placing carbon or hydrogen in the wrong position. Carbon sits between aluminium and zinc, and hydrogen between iron and copper.
2
Saying all metals react with dilute acid. Copper, silver and gold do not.
3
Predicting a displacement in the wrong direction. The more reactive metal always displaces the less reactive one.
4
Assuming aluminium is unreactive because it seems inert. Its protective oxide layer hides its high reactivity.
Last updated:
\n