Redox Reactions Practice Questions

Class 11 · Chemistry · 1677 free MCQs with instant results and detailed explanations.

1677

Total

460

Easy

920

Medium

297

Hard

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Topics in Redox Reactions

Balancing Redox Equations 760

Oxidation and Reduction 888

Oxidation Number 29

Sample Questions from Redox Reactions

Here are 10 sample questions. Start a quiz to get randomized questions with scoring.

Easy

Which of the following represents an oxidation reaction?

A. 4Fe + 3O2 → 2Fe2O3

B. 2H2 + O2 → 2H2O

C. 2Na + Cl2 → 2NaCl

D. C + O2 → CO2

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Correct Answer: A

In reaction A, iron (Fe) is oxidized to Fe2O3, losing electrons.

Easy

Which of the following is a reducing agent?

A. Cl2

B. H2

C. NaCl

D. O2

Show Answer & Explanation

Correct Answer: B

H2 acts as a reducing agent because it donates electrons in reactions.

Easy

In a redox reaction, what happens to the oxidation state of the oxidized substance?

A. It decreases.

B. It increases.

C. It remains the same.

D. It becomes negative.

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Correct Answer: B

In oxidation, the oxidation state of the oxidized substance increases.

Medium

Which of the following statements correctly defines oxidation in the context of redox reactions?

A. Loss of electrons or an increase in oxidation state.

B. Gain of protons.

C. Decrease in temperature.

D. Formation of a precipitate.

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Correct Answer: A

Oxidation is defined as the loss of electrons, which leads to an increase in oxidation state. It is a fundamental concept in redox reactions.

Medium

In a redox reaction, which species is reduced?

A. The one that gains electrons.

B. The one that loses electrons.

C. The one that forms a gas.

D. The one that precipitates.

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Correct Answer: A

Reduction involves the gain of electrons, leading to a decrease in oxidation state of the species.

Medium

In the reaction 2Fe + 3Cl2 → 2FeCl3, what is the reducing agent?

A. Fe

B. Cl2

C. FeCl3

D. None of the above

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Correct Answer: A

Fe is oxidized to FeCl3 and thus acts as the reducing agent because it donates electrons.

Medium

Which of the following elements can act as an oxidizing agent?

A. Oxygen

B. Sodium

C. Calcium

D. Potassium

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Correct Answer: A

Oxygen is a strong oxidizing agent because it readily accepts electrons during redox reactions.

Hard

In a redox reaction, which of the following species is oxidized?

A. Fe^2+ to Fe^3+

B. Cu^2+ to Cu

C. Ag^+ to Ag

D. Mg to Mg^2+

Show Answer & Explanation

Correct Answer: A

In the reaction, Fe^2+ loses an electron to become Fe^3+, indicating oxidation.

Hard

What is the change in oxidation state of sulfur in the reaction 2H2S + SO2 → 3S + 2H2O?

A. From -2 to 0

B. From 0 to -2

C. From +4 to -2

D. From -2 to +4

Show Answer & Explanation

Correct Answer: A

Sulfur in H2S has an oxidation state of -2 and in elemental sulfur, it is 0.

Q10

Hard

In a galvanic cell, which of the following describes the half-reaction occurring at the cathode?

A. Reduction occurs.

B. Oxidation occurs.

C. Electrons are produced.

D. Anions migrate towards the anode.

Show Answer & Explanation

Correct Answer: A

The cathode is where reduction takes place, gaining electrons.

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Redox Reactions — Class 11 Chemistry Practice Questions Online

This page contains 1677 practice MCQs for the chapter Redox Reactions in Class 11 Chemistry. The questions are organized by difficulty — 460 easy, 920 medium, 297 hard — so you can choose the right level for your preparation.

Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 3 topics, giving you comprehensive coverage of the entire chapter.