250+ TOP MCQs on Classical Idea of Redox Reactions-Oxidation and Reduction Reactions and Answers

Chemistry Multiple Choice Questions on “Classical Idea of Redox Reactions-Oxidation and Reduction Reactions”.

1. In the reaction of formation of magnesium oxide magnesium undergoes ________
a) reduction
b) oxidation
c) hydrogenation
d) decomposition
Answer: b
Clarification: Oxidation is a process that involves the addition of oxygen to an element or compound or the removal of hydrogen from a compound, an example is of this is the formation of magnesium oxide from magnesium.

2. A zinc ion is formed due to oxidation.
a) true
b) false
Answer: a
Clarification: Oxidation is the loss of electrons by an atom, ion or molecule. it is also known as de^–electronation. Zn → Zn²⁺ + 2e^–, the loss of electrons from zinc i.e. formation of zinc is an example of oxidation.

3. Removal of oxygen from a compound is an example of ________
a) oxidation
b) reduction
c) oxygenation
d) dehydrogenation
Answer: b
Clarification: Reduction is a chemical process, which involves the addition of hydrogen or an element or compound for the removal of oxygen from a compound. An example of reduction is a chemical reaction;
H₂ + F₂ → 2HF.

4. Reduction involves in __________ oxidation number.
a) decrease
b) increase
c) independence
d) remain constant
Answer: a
Clarification: The oxidation number is recharged in which an atom appears to have when all the atoms are removed from it as ions. It may have +ve or -ve sign. Reduction results in a decrease in the oxidation number.

5. Formation of copper from copper iron is an example of a reduction.
a) true
b) false
Answer: a
Clarification: Reduction is the gain of electrons by an atom, ion or molecule this process is known as electronation. Prayer for the formation of copper from copper iron as an example of reduction reaction because the copper gains two electrons in this case.

6. Oxidation is the same as __________
a) addition of hydrogen
b) removal of oxygen
c) addition of oxygen
d) removal of Nitrogen
Answer: c
Clarification: Oxidation is the same as the addition of oxygen or removal of hydrogen where reduction is the addition of hydrogen or removal of oxygen. Oxidation is caused by an oxidising agent and reduction is caused by a reducing agent.

7. Formation of zinc sulphide is an example of ___________
a) reduction
b) oxidation
c) removal of oxygen
d) addition of hydrogen
Answer: b
Clarification: Addition of electronegative element or removal of any other electropositive element is also considered as a process that involves oxidation. Here, sulphur is an electronegative element. So the formation of zinc sulphide is an Oxidation reaction.

8. SnCl₂ + 2FeCl₂ → SnCl₄ + 2FeCl₂ is an example of __________________ reaction.
a) only oxidation
b) only reduction
c) redox
d) neither oxidation nor reduction
Answer: c
Clarification: Chemical reactions which involves both oxygen as well as reduction process simultaneously are known as redox reactions. The above given reaction involves both oxidation and reduction reactions, so it is a Redox reaction.

9. SnCl₂ + 2FeCl₂ → SnCl₄ + 2FeCl₂. Which of the following element undergoes oxidation in the reaction given?
a) iron
b) tin
c) chlorine
d) ferrous
Answer: b
Clarification: Tin changes is oxidation state from + 2 to + 4. Increase in oxidation number indicates Oxidation reaction. Oxidation is the loss of electrons by an atom, ion or molecule, it is also known as the de^–electronation.

10. Which of the following do you think is a correct statement?
a) oxidation is caused by a reducing agent
b) the oxidation reaction is a Redox reaction
c) addition of electropositive element is a type of oxidation
d) reduction is the addition of hydrogen
Answer: d
Clarification: Oxidation is caused by an oxidizing agent, both oxidation and reduction reaction is combined together to form a Redox reaction and the addition of electropositive element is a type of reduction so the correct statement is that reduction as the addition of hydrogen.