AQA GCSE FOUNDATION Chemistry: The Reactivity Series

AQA GCSE Foundation Chemistry: The Reactivity Series

This tutorial will guide you through understanding the reactivity series of metals, focusing on its practical applications in reactions with water and acids.

What is the Reactivity Series?

The reactivity series is a list of metals arranged in order of their decreasing reactivity. This means the metals at the top are the most reactive, while those at the bottom are the least reactive.

Here's a common version of the reactivity series:

1. Potassium (K)
2. Sodium (Na)
3. Lithium (Li)
4. Calcium (Ca)
5. Magnesium (Mg)
6. Aluminium (Al)
7. Zinc (Zn)
8. Iron (Fe)
9. Tin (Sn)
10. Lead (Pb)
11. Copper (Cu)
12. Silver (Ag)
13. Gold (Au)
14. Platinum (Pt)

Reactivity with Water

• Highly reactive metals (K, Na, Li, Ca) react vigorously with cold water, producing hydrogen gas and a metal hydroxide solution. This reaction is exothermic, meaning it releases heat.
• Moderately reactive metals (Mg, Al) react slowly with cold water but react more vigorously with steam, producing hydrogen gas and a metal oxide.
• Less reactive metals (Zn, Fe, Sn, Pb) do not react with cold water but react with steam to produce hydrogen gas and a metal oxide.
• Unreactive metals (Cu, Ag, Au, Pt) do not react with water or steam.

Example:

Sodium + Water ? Sodium hydroxide + Hydrogen gas
2Na(s) + 2H?O(l) ? 2NaOH(aq) + H?(g)

Reactivity with Acids

• Metals above hydrogen in the reactivity series react with dilute acids to produce a salt and hydrogen gas.
• Metals below hydrogen in the reactivity series do not react with dilute acids.

Example:

Zinc + Hydrochloric acid ? Zinc chloride + Hydrogen gas
Zn(s) + 2HCl(aq) ? ZnCl?(aq) + H?(g)

Practical Applications of the Reactivity Series

• Extraction of metals: Metals high in the reactivity series are usually extracted using electrolysis, while those lower in the series can be extracted by reducing their ores.
• Corrosion: Metals high in the reactivity series corrode more readily than those lower down. Understanding this helps us choose suitable metals for different applications.
• Displacement reactions: A more reactive metal can displace a less reactive metal from its compound. This is a common method for extracting metals.

Example:

Iron + Copper sulfate ? Iron sulfate + Copper
Fe(s) + CuSO?(aq) ? FeSO?(aq) + Cu(s)

Key Points to Remember:

• The reactivity series is a vital tool for understanding the chemical behavior of metals.
• Metals higher in the series are more reactive than those lower down.
• The reactivity of a metal can be tested by its reaction with water and acids.
• The reactivity series has numerous practical applications in everyday life and industry.

This tutorial provides a basic understanding of the reactivity series. For further exploration, consult your textbook and other resources. Remember to always practice safety measures when working with chemicals in the lab.