50+ JEE Mains MCQ Questions Redox Reactions with Solutions

Preparing for the Joint Entrance Exam (JEE) can be a daunting task. With so many subjects to cover and so many topics to study, it can be challenging to know where to start. One essential topic in the JEE Mains syllabus is the Redox Reactions. In this article, we will provide 50+ MCQ questions on the Redox Reactions, along with detailed solutions to help you prepare for the JEE Mains exam.

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These 50+ MCQ questions are selected by the experts of studyrate.in and these are more difficult questions, which will help you to better understand Redox Reactions JEE Mains MCQ Questions with Answers.

Redox Reactions JEE Mains MCQ


In the reaction Zn + H₂SO₄ → ZnSO₄ + H₂, the oxidation state of zinc changes from:
A) 0 to +2
B) +2 to 0
C) 0 to -2
D) -2 to 0

Answer: A Explanation: In the reaction, the oxidation state of zinc changes from 0 (in elemental form) to +2 (in ZnSO₄).

In the reaction 2KClO₃ → 2KCl + 3O₂, the element undergoing reduction is:
A) K
B) Cl
C) O
D) None of the above

Answer: C Explanation: In the reaction, oxygen (O) is undergoing reduction as its oxidation state decreases from 0 to -2 in O₂.

The equivalent weight of KMnO₄ in acidic medium is equal to:
A) Molar mass of KMnO₄
B) Molar mass of KMnO₄ divided by 5
C) Molar mass of KMnO₄ divided by 3
D) Molar mass of KMnO₄ divided by 2

Answer: B Explanation: In acidic medium, KMnO₄ undergoes reduction to Mn²⁺. One mole of KMnO₄ reacts with 5 moles of electrons. Therefore, the equivalent weight of KMnO₄ is its molar mass divided by 5.

In the reaction 2Mg + O₂ → 2MgO, which species is being reduced?
A) Mg
B) O₂
C) MgO
D) None of the above

Answer: B Explanation: In the reaction, oxygen (O₂) is being reduced as its oxidation state changes from 0 to -2 in MgO.

In the reaction Cu + 2AgNO₃ → Cu(NO₃)₂ + 2Ag, the reducing agent is:
A) Cu
B) Ag
C) Cu(NO₃)₂
D) None of the above

Answer: A Explanation: In the reaction, copper (Cu) is the reducing agent as it loses electrons and undergoes oxidation, thereby reducing silver ions to elemental silver (Ag).


In the reaction 2KMnO₄ + 3H₂SO₄ + 5H₂C₂O₄ → K₂SO₄ + 2MnSO₄ + 8H₂O + 10CO₂, the oxidizing agent is:
A) KMnO₄
B) H₂SO₄
C) H₂C₂O₄
D) CO₂

Answer: A Explanation: In the reaction, KMnO₄ acts as an oxidizing agent as it undergoes reduction, changing from Mn(VII) to Mn(II) in the product MnSO₄.

In the reaction 2H₂O₂ + 2HI → 2H₂O + I₂, the species that undergoes oxidation is:
A) H₂O₂
B) HI
C) H₂O
D) I₂

Answer: A Explanation: In the reaction, hydrogen peroxide (H₂O₂) is oxidized to water (H₂O) as its oxidation state changes from -1 to 0.

The cell potential (E°cell) for a galvanic cell is given by the formula:
A) E°cell = E°cathode – E°anode
B) E°cell = E°anode – E°cathode
C) E°cell = E°anode + E°cathode
D) E°cell = E°cathode × E°anode

Answer: B Explanation: The cell potential (E°cell) for a galvanic cell is determined by subtracting the reduction potential of the anode (E°anode) from the reduction potential of the cathode (E°cathode).

In the reaction Cu + 2HNO₃ → Cu(NO₃)₂ + 2NO + H₂O, the reducing agent is:
A) Cu
B) HNO₃
C) Cu(NO₃)₂
D) H₂O

Answer: A Explanation: In the reaction, copper (Cu) acts as the reducing agent as it loses electrons and undergoes oxidation, reducing nitric acid (HNO₃) to nitric oxide (NO).

The oxidation number of nitrogen in HNO₂ is:
A) -1
B) +1
C) +2
D) +3

Answer: D Explanation: In HNO₂, the oxidation number of nitrogen (N) is +3 as it gains an electron from hydrogen (H) and has a -1 charge.


Which of the following statements is true regarding a redox reaction?
A) Oxidation involves a decrease in oxidation state.
B) Reduction involves an increase in oxidation state.
C) Oxidation involves a decrease in the number of oxygen atoms.
D) Reduction involves a decrease in the number of hydrogen atoms.

Answer: B Explanation: Reduction involves a decrease in the oxidation state of a species, which is often accompanied by a gain of electrons.

In the reaction 2MnO₄⁻ + 16H⁺ + 5C₂O₄²⁻ → 2Mn²⁺ + 8H₂O + 10CO₂, the substance undergoing reduction is:
A) MnO₄⁻
B) H⁺
C) C₂O₄²⁻
D) Mn²⁺

Answer: A Explanation: In the reaction, MnO₄⁻ undergoes reduction, as the oxidation state of manganese (Mn) decreases from +7 to +2.

Which of the following substances acts as a reducing agent in the reaction 2Na + Cl₂ → 2NaCl?
A) Na
B) Cl₂
C) NaCl
D) None of the above

Answer: A Explanation: In the reaction, sodium (Na) acts as a reducing agent as it loses electrons and undergoes oxidation, reducing chlorine (Cl₂) to chloride ions (Cl⁻).

The oxidation state of sulfur in H₂SO₅ is:
A) +6
B) +5
C) +4
D) +2

Answer: B Explanation: In H₂SO₅, the oxidation state of sulfur (S) is +5, as each oxygen (O) atom has an oxidation state of -2 and the sum of all the oxidation states in the compound is zero.

In the reaction Fe²⁺ + Cr₂O₇²⁻ + 14H⁺ → Fe³⁺ + 2Cr³⁺ + 7H₂O, the substance acting as the oxidizing agent is:
A) Fe²⁺
B) Cr₂O₇²⁻
C) H⁺
D) Fe³⁺

Answer: B Explanation: In the reaction, Cr₂O₇²⁻ acts as the oxidizing agent as it undergoes reduction, changing from Cr(VI) to Cr(III) in the product Cr³⁺.


In the reaction 2KMnO₄ + 10FeSO₄ + 8H₂SO₄ → 5Fe₂(SO₄)₃ + 2MnSO₄ + K₂SO₄ + 8H₂O, the substance acting as the oxidizing agent is:
A) KMnO₄
B) FeSO₄
C) H₂SO₄
D) K₂SO₄

Answer: A

The reduction potential of a half-reaction is a measure of:
A) The tendency of a substance to gain electrons.
B) The tendency of a substance to lose electrons.
C) The concentration of the reactants in a redox reaction.
D) The pressure of the reactants in a redox reaction.

Answer: A

In the reaction Zn + 2HCl → ZnCl₂ + H₂, the substance that undergoes oxidation is:
A) Zn
B) HCl
C) ZnCl₂
D) H₂

Answer: A

The oxidation state of oxygen in OF₂ is:
A) -1
B) 0
C) +1
D) +2

Answer: D

In the reaction MnO₄⁻ + 5Fe²⁺ + 8H⁺ → Mn²⁺ + 5Fe³⁺ + 4H₂O, the substance being reduced is:
A) MnO₄⁻
B) Fe²⁺
C) H⁺
D) Fe³⁺

Answer: A

The standard electrode potential (E°) of a half-cell is measured under standard conditions, which include:
A) Concentration of 1 M for all species.
B) Pressure of 1 atm for all gases involved.
C) Temperature of 25°C (298 K).
D) All of the above.

Answer: D

In the reaction 2H₂O → 2H₂ + O₂, the substance undergoing oxidation is:
A) H₂O
B) H₂
C) O₂
D) None of the above

Answer: C

Which of the following elements can exhibit multiple oxidation states?
A) Sodium (Na)
B) Silver (Ag)
C) Zinc (Zn)
D) Chromium (Cr)

Answer: D

The oxidation state of sulfur in H₂SO₄ is:
A) +6
B) +4
C) +2
D) -2

Answer: A

In the reaction 2Cu + O₂ → 2CuO, the substance acting as the reducing agent is:
A) Cu
B) O₂
C) CuO
D) None of the above

Answer: A

The oxidation state of nitrogen in NH₃ is:
A) -1
B) +1
C) +2
D) +3

Answer: -3

In the reaction 2KMnO₄ + 3H₂SO₄ + 5H₂C₂O₄ → K₂SO₄ + 2MnSO₄ + 8H₂O + 10CO₂, the substance acting as the oxidizing agent is:
A) KMnO₄
B) H₂SO₄
C) H₂C₂O₄
D) CO₂

Answer: C

The reducing agent in a redox reaction is the species that:
A) Gains electrons and undergoes reduction.
B) Loses electrons and undergoes reduction.
C) Gains electrons and undergoes oxidation.
D) Loses electrons and undergoes oxidation.

Answer: A

In the reaction Zn + CuSO₄ → ZnSO₄ + Cu, the substance being reduced is:
A) Zn
B) CuSO₄
C) ZnSO₄
D) Cu

Answer: B

Which of the following reactions is an example of a redox reaction?
A) NaCl + H₂O → NaOH + HCl
B) HCl + NaOH → NaCl + H₂O
C) CaCO₃ → CaO + CO₂
D) CH₄ + 2O₂ → CO₂ + 2H₂O

Answer: D

The oxidation number of chlorine in HClO₃ is:
A) -1
B) +1
C) +3
D) +5

Answer: D

In the reaction 2KClO₃ → 2KCl + 3O₂, the substance that acts as the oxidizing agent is:
A) KClO₃
B) KCl
C) O₂
D) None of the above

Answer: A

Which of the following elements is reduced in the reaction 2Na + Cl₂ → 2NaCl?
A) Sodium (Na)
B) Chlorine (Cl)
C) Sodium chloride (NaCl)
D) None of the above

Answer: B

The oxidation number of sulfur in SO₂ is:
A) +2
B) -2
C) +4
D) -4

Answer: +4

In the reaction 2H₂O₂ + 2HI → 2H₂O + I₂, the substance acting as the reducing agent is:
A) H₂O₂
B) HI
C) H₂O
D) I₂

Answer: A

We hope there JEE MCQ of Class 11 Redox Reactions will help you to score an excellent rank in JEE Mains and Advanced. If you have any queries feel free to write in the comments section. We at Study Rate are always ready to serve our students.

Sneha

Master's in Biology, Skilled in vocational training. Strong Analytical and creative knowledge.

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