# Displacement reaction

A reaction in which a more reactive element pushes a less reactive element out of its compound.

Chemistry (school) · Part 07: Metals and electrolysis · Card 2 of 9 · Last updated 2026-10-19

## Analogy

Like a bigger kid taking a smaller kid's seat on the bus.

## Example

**Iron and copper sulfate**

iron + copper sulfate
-> iron sulfate + copper
Fe + CuSO4 -> FeSO4 + Cu

## In practice

An iron nail in blue copper sulfate solution becomes coated with brown copper.

## Practice

### Flashcards

- **What happens in a displacement reaction?** A more reactive element takes the place of a less reactive one in a compound.

## Questions people ask

### How can you tell a displacement reaction has happened?

Look for a colour change in the solution and a new coating on the metal. When iron is placed in blue copper sulfate, the solution fades towards pale green and the nail gets a pink-brown layer of copper. The temperature may also rise a little.

### What is the thermite reaction?

Aluminium powder is mixed with iron oxide and ignited. Aluminium is more reactive and takes the oxygen, leaving molten iron and a lot of heat. The reaction is used to weld railway tracks together. It is a dramatic example of a displacement reaction.

## Related concepts

- [Reactivity series](https://studyvisually.com/learn/science/chemistry-school/chemistry-school-part-7/chemistry-school-part-7-concept-1)

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