Metals - Reactivity Series & Reactivity
Chemistry: Cambridge International GCSE Supplement, topic 9.4.1
Metals - Reactivity Series and Reactivity
The reactivity series orders metals from potassium to gold. Higher metals react vigorously with water or steam and acids, displacing hydrogen.
The reactivity series order
- The reactivity series orders metals by their reactivity.
- The order is: potassium, sodium, calcium, magnesium, aluminium, carbon, zinc, iron, hydrogen, copper, silver, gold.
- Potassium is the most reactive metal in this series.
- Gold is the least reactive metal.
- Carbon is included to compare with metals in extractions.
Reactions with cold water
- Potassium reacts very quickly with cold water, producing hydrogen gas and potassium hydroxide.
- Sodium reacts rapidly with cold water, producing sodium hydroxide and hydrogen gas.
- 2Na + 2H₂O → 2NaOH + H₂
- Calcium reacts slowly with cold water forming calcium hydroxide and hydrogen gas.
- These reactions demonstrate how metals higher in the reactivity series react more vigorously.
- Reactions like these release hydrogen gas, which can be seen bubbling.
Magnesium reaction with steam
- Magnesium does not react quickly with cold water but reacts with steam.
- Magnesium reacts with steam to produce magnesium oxide and hydrogen gas.
- This shows magnesium is less reactive than calcium but still reacts with water in steam form.
- Magnesium must be heated to react with water as steam.
Reactivity with dilute hydrochloric acid
- Magnesium reacts rapidly with dilute hydrochloric acid, producing magnesium chloride and hydrogen gas.
- Zinc and iron react with dilute hydrochloric acid slowly, producing zinc chloride, iron chloride, and hydrogen gas.
- Copper, silver, and gold do not react with dilute hydrochloric acid.
- The reactivity decreases down the series, metals below hydrogen do not react with acids.
- Metal reactivity relates directly to whether the metal displaces hydrogen from acid.
Summary and explanation
- The reactivity series shows how easily metals lose electrons and react.
- Metals higher in the series lose electrons easily, reacting strongly with water and acids.
- Metals below hydrogen in the series do not react with dilute acids.
- This chemical behaviour helps decide how metals are extracted and used.
Test yourself on Metals - Reactivity Series & Reactivity
Which two statements correctly describe the characteristics of metals that are higher in the reactivity series?
What reactions occur when metals react?