Displacement Reaction MCQs Quiz | Class 10

Test your knowledge with this Displacement Reaction MCQs Quiz for Class 10 Science (Unit I: Chemical Substances – Nature and Behaviour). This practice set covers the definition of displacement, identification of reactions using the reactivity series, and real-world examples like iron in copper sulphate. Submit your answers to see the score and download the solution PDF.

Displacement Reaction: Overview

A displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound. This concept is fundamental to understanding the reactivity series of metals. The general form of a single displacement reaction is written as:

A + BC -> AC + B

Here, element A is more reactive than element B, so it replaces B in the compound BC.

The Reactivity Series

To predict whether a displacement reaction will occur, students must use the reactivity series. Metals at the top (like Potassium, Sodium, Calcium) are highly reactive, while those at the bottom (like Silver, Gold, Platinum) are least reactive.

  • Rule: A metal can only displace another metal if it is placed above it in the reactivity series.
  • Example: Zinc is above Copper. Therefore, Zn + CuSO4 -> ZnSO4 + Cu occurs.
  • Counter-Example: Copper is below Zinc. Therefore, Cu + ZnSO4 -> No Reaction.

Key Observations

Displacement reactions often involve visible changes, such as:

Reactants Observation
Iron nail in Copper Sulphate Blue solution turns pale green; reddish-brown coating on iron.
Zinc in Copper Sulphate Blue solution becomes colorless.

Quick Summary for Exams

  1. Look for a single element reacting with a compound.
  2. Check the position of the single element in the reactivity series.
  3. If the single element is higher, the reaction happens. If lower, no reaction.
  4. Hydrogen can also be displaced from acids by metals above Hydrogen (e.g., Zn, Mg, Fe).

Extra Practice Questions

1. What happens when Aluminum reacts with Iron(III) oxide? (Thermite reaction)
2. Can Silver displace Hydrogen from HCl?
3. Write the balanced equation for Magnesium + Copper Sulphate.
4. Why does Gold not react with water or acids easily?
5. Identify the displacing element in: Pb + CuCl2 -> PbCl2 + Cu.