250+ TOP MCQs on Redox Reactions and Electrode Processes and Answers

Chemistry Multiple Choice Questions on “Redox Reactions and Electrode Processes”.

1. S + O₂ → SO₂ is an example of ______________
a) combination
b) decomposition
c) disproportionation
d) double decomposition
Answer: a
Clarification: The chemical combination reaction results in the formation of a new compound from two elements substances. The above formation of Sulphur dioxide from Sulphur and oxygen is a type of combination reaction.

2. 2H₂O → 2H₂ + O₂ is an example of ______________
a) combination
b) decomposition
c) disproportionation
d) double decomposition
Answer: b
Clarification: The reverse reaction of a combination reaction as a decomposition reaction. In a decomposition reaction, the breakdown of a compound happens into two or more components, here water is broken down into hydrogen and oxygen, so it is a decomposition reaction.

3. The exchange of salt between zinc and copper is an example of ______________
a) combination
b) decomposition
c) disproportionation
d) displacement
Answer: d
Clarification: An ion in a compound is replaced by an ion of other element is a sort of displacement reaction. Here the ions are salts, the exchange of salts between zinc and copper is an example of a displacement reaction.

4. Breakdown of hydrogen peroxide into water and oxygen is an example of ______________
a) combination
b) decomposition
c) disproportionation
d) double decomposition
Answer: c
Clarification: Disproportionation reactions are a special type of redox reactions. In this type of redox reactions, a single compound undergoes oxidation and reduction at the same time. The breakdown of hydrogen peroxide into water and hydrogen, the same thing happens.

5. Displacement reaction is of two types.
a) true
b) false
Answer: a
Clarification: Yes, the above statement is true, because, in displacement reactions, there are two types. One is the metal displacement and the other is nonmetal displacement, both of them are redox reactions.

6. X + YZ → XZ + Z is a form of ______________
a) combination reaction
b) displacement reaction
c) disproportionate reaction
d) decomposition reaction
Answer: b
Clarification: In a displacement reaction, a metal or a non-metal, in a compound can be displaced by another metal in the uncombined state. So the above reaction X + YZ → XZ + Z, is a displacement reaction.

7. Can ClO₄^– exhibit disproportionation reaction?
a) may be
b) yes
c) no
d) cannot say
Answer: c
Clarification: The above ion cannot its show disproportionation reaction because the chlorine in ClO₄^– is present in its maximum Oxidation state, that is +7. Disproportionation reaction occurs only when it is present in its intermediate Oxidation State.

8. 2F₂ + 2OH^– → 2F^– + OF₂ + H₂O is a type of ______________
a) combination reaction
b) displacement reaction
c) disproportionate reaction
d) decomposition reaction
Answer: c
Clarification: Disproportion reaction occurs when an element in a compound after reactions splits into two different oxidation States i.e. it is reduced and oxidized. In the above reaction. Florine is reduced as well as oxidized, so it is a disproportionate reaction.

9. 2NaH → 2Na + H₂ is an example of a combination reaction.
a) True
b) False
Answer: b
Clarification: The above statement is considered to be false because it is a decomposition reaction as sodium hydride is broken down into Sodium and hydrogen. A combination of reaction results in the formation of a new compound instead of breaking down.

10. Which of the following reaction is a combination reaction?
a) X + YZ → XZ + Z
b) 2F₂ + 2OH^– → 2F^– + OF₂ + H₂O
c) 2NaH → 2Na + H₂
d) S + O₂ → SO₂
Answer: d
Clarification: Only the reaction; S + O₂ → SO₂ is a chemical combination reaction, whereas X + YZ → XZ + Z and 2F₂ + 2OH^– → 2F^– + OF₂ + H₂O are disproportionation reactions and 2NaH → 2Na + H₂ is a chemical decomposition reaction.