The reactivity series
Introduced| English | Meaning |
|---|---|
| reactivity series/rɪəkˈtɪvɪti ˈsɪəriːz/ | An ordering of metals according to their tendency to react by losing electrons. |
| displace/dɪˈspleɪs/ | To replace another element in a compound during a chemical reaction. |
Ranking the metals
- Some metals react violently; others barely react at all.
- The reactivity series 金属活动性顺序 ranks metals from most to least reactive.
Which of these metals is the most reactive?
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Potassium is near the top of the reactivity series.
Put these metals in order from most reactive to least reactive.
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Potassium > magnesium > iron > gold.
Being very unreactive, ______ is found near the bottom of the reactivity series.
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Gold is one of the least reactive metals.
The reactivity series
- Metals are listed from most reactive (potassium) to least reactive (gold).
- The order: potassium, sodium, calcium, magnesium, zinc, iron, copper, gold (and more).
The reactivity series ranks metals from most reactive at the top to least reactive at the bottom.
Displacement and the reactivity series
Step through a displacement. A more reactive metal pushes a less reactive one out of its compound — which is exactly what the reactivity series predicts.
A more reactive metal can:
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More reactive metals displace less reactive ones.
Displacement reactions
- A more reactive metal will displace 置换 a less reactive one from its compound.
- For example, iron displaces copper from copper sulfate solution.
An iron nail placed in copper sulfate solution will:
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Iron is more reactive than copper, so it displaces it.
Reactions with water and acid
- The most reactive metals react with cold water; less reactive ones only with acid; the least don't react.
- The series predicts how vigorously a metal will react.
Worked example. Put an iron nail in copper sulfate solution. Iron is more reactive than copper, so it displaces it: the nail gets a copper coating and the blue solution fades. The series predicts the result.
You've got it
- the reactivity series ranks metals from most (potassium) to least (gold) reactive
- a more reactive metal displaces a less reactive one from its compound
- the series predicts reactions with water and acid
Write from extraction by electrolysis
- Magnesium is above carbon in the reactivity series.
- Gold is near the bottom and is found as the element.
How is magnesium extracted from its ore?
Metals more reactive than carbon are extracted by electrolysis.
How is magnesium obtained from its compounds?
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Carbon cannot take the oxygen from magnesium oxide.