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Chemical Reactions, Oxidation and Reduction

Learn reaction types and redox logic for objective accuracy.

Level

Core

Study Time

20 min

Exam Relevance

High

Core concepts

  • Combination, decomposition, displacement and double displacement.
  • Oxidation and reduction in terms of electron transfer.
  • Oxidizing and reducing agents.

Exam-solving method

  1. Identify what changes (gain/loss of oxygen, hydrogen or electrons).
  2. Separate oxidized and reduced species.
  3. Match with reaction type options.

Common mistakes

  • Treating oxidation only as oxygen addition in all cases.
  • Misidentifying oxidizing agent.

Chapter-end mini quiz

5 quick questions from the question bank.

Question 1

The chemical reaction : 2AgCl (s) → 2Ag (s) + Cl₂ (g) takes place

Question 2

Which one of the following reactions is an example of decomposition reaction?

Question 3

Match List I with List II and select the answer using the code given below the Lists: **List I (Reaction)** — **List II (Type)** A. CaO (s) + H₂O (l) → Ca(OH)₂ (aq) — 1. Single displacement B. CaCO₃ (s) → CaO (s) + CO₂ (g) — 2. Double displacement C. Pb (s) + CuCl₂ (aq) → PbCl₂ (aq) + Cu (s) — 3. Combination D. Na₂SO₄ (aq) + BaCl₂ (aq) → BaSO₄ (s) + 2NaCl (aq) — 4. Decomposition

Question 4

Which one of the following reactions does not result in the evolution of hydrogen gas?

Question 5

Match List I with List II and select the correct answer using the code given below the Lists:\\ List I (Chemical process): <br>A. Electrolysis of water; <br>B. Burning of coal; <br>C. Iron nail immersed in copper sulphate solution; <br>D. Addition of barium chloride solution to aluminium sulphate solution.\\ <br><br>List II (Reaction): <br>1. Double displacement reaction; <br>2. Combination reaction; <br>3. Decomposition reaction; <br>4. Displacement reaction.

Source Base

  • NCERT chapters on chemical reactions and redox basics
  • CBSE pattern questions on oxidation number and reaction type