Free Oxidation and Reduction MCQs with Answers
64 Oxidation and Reduction MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Oxidation involves loss of electrons, increase in oxidation number or addition of oxygen, while reduction involves electron gain, decrease in oxidation number or removal of oxygen. The topic covers oxidising and reducing agents, oxidation-number changes, redox equations and the distinction between oxidation at the anode and reduction at the cathode.
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64 questions · page 3 of 4
- A. Reducing agent
- B. Excellent precipitating reagent
- C. Germicide
- D. Oxidizing agent
Explanation: A is incorrect as KMnO4 isnt a reducing agent.B is incorrect as KMnO4 isnt a precipitating agent.C is incorrect as KMnO4 isnt used in…
Correct answer: Oxidizing agent- A. -8
- B. +8
- C. -6
- D. +6
Explanation: The oxidation of sulphur is 6+:it is because the oxide ion has a charge of -2 making it -8 overall, for four oxide ions.
Correct answer: +6- A. 5+
- B. 2+
- C. 3+
- D. 3-
Explanation: NO3N = xO = - 2x + (-2) × 3 = - 1x + (- 6) = - 1x - 6 = - 1x = - 1 + 6x = 5
Correct answer: 5+- A. -1, +1
- B. -1, +3
- C. -1, +5
- D. +1, +5
Explanation: In NaCl, Na has an oxidation state of +1 so Cl is -1 and in NaClO3, Na is +1 and O is -6 while Cl is an unknown x.
Correct answer: -1, +5- A. Oxidation of Ag
- B. Reduction of Cu
- C. Oxidation of Cu
- D. Ionization of Ag
Explanation: When copper wire is placed in silver nitrate solution then the solution becomes blue colored.
Correct answer: Oxidation of Cu- A. Oxidation of Ag
- B. Reduction of Cu
- C. Oxidation of Cu
- D. Reduction of Ag
Explanation: When copper is added to silver nitrate solution, the following reaction takes place:
Correct answer: Oxidation of Cu- A. -6
- B. +6
- C. -4
- D. +4
Explanation: In sulfuric acid (H2SO4), Hydrogen exists in its normal oxidation state of +1 and Oxygen exists in its normal oxidation state of -2.
Correct answer: +6- A. Ag
- B. Au
- C. Al
- D. Zn
Explanation: In a displacement reaction, a more reactive metal can displace a less reactive metal from its salt solution.
Correct answer: Zn- A. -1
- B. +3
- C. +5
- D. -6
Explanation: This has to be calculatedThe oxidation state of Ca is +2, and oxygen is -2, so:(+2) + (2x) + (6 x -2) = 0; calculating this gives x = +5
Correct answer: +5- A. Ag
- B. AU
- C. Pt
- D. Zn
Explanation: A more reactive metal can displace a less reactive metal from its salt in an aqueous solution.
Correct answer: Zn- A. -1
- B. +3
- C. +5
- D. -6
Explanation: In the compound Ca(ClO3)2, calcium has an oxidation state of +2, being a Group 2 metal. Each ClO3- ion must balance to -1 overall charge.
Correct answer: +5- A. +3
- B. +2
- C. +4
- D. +6
Explanation: OPTION B is correct as there six ligands in the compound which is a cyano group having a charge of -1.
Correct answer: +2- A. Oxidize the compound
- B. Reduce the compound
- C. Electrolyze the compound
- D. None of the above
Explanation: Oxidize the compound: A stronger reduction potential indicates that the compound is more likely to undergo reduction rather than…
Correct answer: Oxidize the compound- A. MnO2
- B. Cl2
- C. NaOH
- D. Na2O2
Explanation: NaOH is not an oxidizing agent. It is a strong base that does not readily accept electrons or participate in redox reactions.
Correct answer: NaOH- A. Cl^-
- B. Ne
- C. Na
- D. Ca
Explanation: The correct answer is Ca. Calcium, as a metal, has a low electronegativity and readily donates electrons, making it a strong reducing…
Correct answer: Ca- A. Small negative values
- B. Large negative values
- C. Small positive values
- D. Large positive values
Explanation: The correct answer is Large negative values. A strong reducing agent has a large negative standard reduction potential.
Correct answer: Large negative values- A. I-1> Br->Cl-> F-
- B. F->Cl-> Br-> l-
- C. l-1>Cl-> F-> Br-
- D. Br->Cl-> l-> F-
Explanation: From the reduction potential values, it can be seen that iodide is the best-reducing agent.
Correct answer: I-1> Br->Cl-> F-- A. +4
- B. +2
- C. -1
- D. -4
Explanation: We know that the charge of Na is always +1, and the overall charge on the Na2C2 molecule is 0.
Correct answer: -1- A. Strong oxidizing agent
- B. Strong reducing agent
- C. Very weak oxidizing agent
- D. Very weak reducing agent
Explanation: The correct answer is that chromium compounds in which the oxidation state of chromium is 2+ behave as strong reducing agents.
Correct answer: Strong reducing agent- A. H2 + Cl2 --> 2HCl
- B. C2H4 + H2 --> C2H6
- C. 2Na + H2 --> 2NaH
- D. N2 + 3H2 --> 2NH3
Explanation: In the correct reaction, 2Na + H2 --> 2NaH, sodium (Na) is oxidized, as it loses electrons to form Na+, while hydrogen (H2) is reduced to…
Correct answer: 2Na + H2 --> 2NaH