high importancemedium difficulty4 min

Displacement Reaction

A displacement reaction is a reaction in which a more reactive element pushes out a less reactive element from its compound.

In one line: More reactive wins the place.

Practice This Concept

Understand it

This reaction depends on the reactivity series. A more reactive metal can replace a less reactive metal from its salt solution. The same idea also works for some non-metals in special cases.

Example

Iron placed in copper sulphate solution displaces copper.

Rule to remember

General pattern: A + BC → AC + B, when A is more reactive than B.

See it worked out

Follow the example line by line, then use the same method on new questions.

Worked example

1Fe + CuSO₄ → FeSO₄ + Cu.
2Iron replaces copper, so it is a displacement reaction.

Method you can reuse

1Identify the free element and the compound.
2Compare reactivity.
3If the free element is more reactive, it displaces another element.

Sketch it in your answer

Show the incoming element replacing the less reactive element in the compound.

Check yourself

Answer the question in your head before opening the answer.

Try it yourself

An iron nail placed in copper sulphate solution gets a copper coating. What type of reaction is this?

Think first, then show answer

It is a displacement reaction because iron is more reactive and removes copper from the solution.

Common wrong answer

Saying it is double displacement because two substances are involved.

Why it loses marks: Only one element is replaced.

Don't mix this up

Students often forget that the replacing element must be more reactive than the displaced one.

Exam tip

Always compare reactivity before naming the reaction. Without reactivity, displacement cannot be decided.

Write it in the exam

Each point is worth about one mark. Write point 1 for a 1-mark question and keep adding points as the marks go up.

How CBSE asks it

Questions often ask for the reaction type when one metal is deposited and another is removed from solution.

1
Enough for 1 mark
A displacement reaction is a reaction in which a more reactive element pushes out a less reactive element from its compound.
2
Add for 2 marks
Example: Iron placed in copper sulphate solution displaces copper.
3
Add for 3 marks
This reaction depends on the reactivity series.

MCQ Quiz

Practice this concept with focused MCQs

Open the concept quiz intro first, review the test details, and then start a focused MCQ set from this concept only. Instant score and answer review are live now.

10 MCQs5 MinutesInstant Results