CN  ChemNexa

Redox Reactions CBSE Class 11 MCQ & Practice Questions

Practice Redox Reactions MCQs for CBSE Class 11 Chemistry with answers, explanations, chapter revision and related ChemNexa mock tests.

Register Free for Full Chemistry Practice

Redox Reactions Revision Guide for CBSE Class 11 Chemistry

Redox Reactions focuses on electron transfer and oxidation-state changes. It supports electrochemistry, inorganic reactions and many analytical calculations.

For CBSE Class 11 Chemistry, practise oxidation-number rules, identifying oxidising and reducing agents, balancing redox equations and equivalent concepts where they are part of the syllabus.

Important Topics

  • Oxidation number rules
  • Oxidation and reduction
  • Oxidising and reducing agents
  • Balancing by oxidation-number method
  • Ion-electron method
  • Redox stoichiometry

Important Formulae & Relationships

  • Increase in oxidation number = oxidation
  • Decrease in oxidation number = reduction
  • Total electrons lost = total electrons gained in a balanced redox process

Use formulas only after checking the required units, sign convention and assumptions for the question.

What to practise in Redox Reactions

Concept Revision

Revise definitions, principles, equations, trends and core ideas from Redox Reactions before attempting MCQs.

Exam-style MCQs

Use chapter-focused multiple-choice practice to improve accuracy, recall and application for CBSE Class 11 Chemistry.

Performance Practice

Attempt ChemNexa tests, review results and return to weak areas for another round of targeted revision.

Top 20 Redox Reactions MCQs with Answers

These public questions are selected from the exact Redox Reactions chapter, screened for topic relevance and deduplicated so repeated versions of the same MCQ are not shown publicly. Use them for quick revision, then sign in to attempt the complete test experience with more questions, results and performance review.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

1. The species with highest oxidation state of chlorine:

  • A. Cl⁻
  • B. ClO⁻
  • C. ClO₃⁻
  • D. ClO₄⁻
Answer: D
Explanation: Perchlorate has +7.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

2. Oxidation number of O in H₂O is:

  • A. +2
  • B. -2
  • C. 0
  • D. +1
Answer: B
Explanation: Oxygen is −2 in water.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

3. Oxidation number of H in NaH is:

  • A. +1
  • B. -1
  • C. 0
  • D. +2
Answer: B
Explanation: Hydrogen is −1 in metal hydrides.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

4. Oxidation number of Mn in KMnO₄ is:

  • A. +4
  • B. +6
  • C. +7
  • D. +2
Answer: C
Explanation: K=+1,O=-2.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

5. Oxidation number of Cr in K₂Cr₂O₇ is:

  • A. +3
  • B. +6
  • C. +7
  • D. +2
Answer: B
Explanation: Calculated as +6.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

6. Combination of oxidation and reduction is:

  • A. Hydrolysis
  • B. Redox reaction
  • C. Substitution
  • D. Addition
Answer: B
Explanation: Definition.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

7. Oxidation number of S in H₂SO₄:

  • A. +4
  • B. +6
  • C. +2
  • D. -2
Answer: B
Explanation: Sulfur is +6.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

8. Oxidation number of N in NH₃:

  • A. -3
  • B. +3
  • C. +5
  • D. 0
Answer: A
Explanation: Nitrogen is −3.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

9. Oxidation number of Cl₂:

  • A. -1
  • B. +1
  • C. 0
  • D. +2
Answer: C
Explanation: Elemental state is zero.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

10. The oxidation number of Fe in Fe₂O₃:

  • A. +2
  • B. +3
  • C. +6
  • D. 0
Answer: B
Explanation: Iron is +3.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

11. Oxidation number of C in CO₂:

  • A. +2
  • B. +4
  • C. -4
  • D. 0
Answer: B
Explanation: Carbon is +4.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

12. Oxidation number of C in CH₄:

  • A. +4
  • B. -4
  • C. 0
  • D. +2
Answer: B
Explanation: Carbon is −4.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

13. Which is a redox reaction?

  • A. NaOH+HCl
  • B. Zn+CuSO₄
  • C. AgNO₃+NaCl
  • D. BaCl₂+Na₂SO₄
Answer: B
Explanation: Zn displaces Cu by electron transfer.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

14. Balancing by oxidation number method conserves:

  • A. Atoms only
  • B. Charge and atoms
  • C. Volume
  • D. Pressure
Answer: B
Explanation: Both mass and charge are balanced.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

15. Oxidation is:

  • A. Gain of electrons
  • B. Loss of electrons
  • C. Gain of protons
  • D. Loss of neutrons
Answer: B
Explanation: Oxidation involves loss of electrons.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

16. Reduction is:

  • A. Gain of electrons
  • B. Loss of electrons
  • C. Gain of oxygen
  • D. Loss of hydrogen
Answer: A
Explanation: Reduction involves gain of electrons.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

17. Oxidising agent:

  • A. Gets oxidised
  • B. Gets reduced
  • C. Loses electrons only
  • D. Donates H
Answer: B
Explanation: Oxidising agent is reduced.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

18. Reducing agent:

  • A. Gets reduced
  • B. Gets oxidised
  • C. Accepts electrons
  • D. Accepts oxygen
Answer: B
Explanation: Reducing agent is oxidised.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

19. In electrochemical terms, oxidation occurs at:

  • A. Cathode
  • B. Anode
  • C. Salt bridge
  • D. Electrolyte
Answer: B
Explanation: Mnemonic: AnOx.

CBSE Class 11 Chemistry · Redox Reactions · Very Very Hard

20. Reduction occurs at:

  • A. Cathode
  • B. Anode
  • C. Wire
  • D. Bridge
Answer: A
Explanation: Mnemonic: RedCat.

Login to Start Full Test

Redox Reactions Practice Tests

Redox Reactions Frequently Asked Questions

How do I identify the oxidising agent?

The oxidising agent causes another species to be oxidised and is itself reduced.

What is the safest way to balance redox equations?

Use either the oxidation-number method or ion-electron method systematically, then verify both atom balance and total charge.

Why is oxidation state useful?

It provides a bookkeeping method for identifying electron-transfer changes even when electrons do not appear explicitly in the written equation.

Continue with another chapter to build connected concepts and strengthen your overall Chemistry preparation.

Continue CBSE Class 11 Chemistry

View all CBSE Class 11 chapters and testsBrowse all Chemistry PracticeCreate a free account