Question

Which of the following is an oxidation-reduction reaction?

Answer 1

Answer: The correct answer is Option a.

Explanation:

Oxidation-reduction reaction or redox reaction is defined as the reaction in which oxidation and reduction reactions occur simultaneously.

Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation state of the substance increases.

Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation state of the substance gets reduced.

For the given options:

Option A: $Fe_2O_3+3CO\rightarrow 2Fe+3CO_2$

On reactant side:

Oxidation state of iron = +3

Oxidation state of carbon = +2

On product side:

Oxidation state of iron = 0

Oxidation state of carbon = +4

The oxidation state of iron reduces from +3 to 0, it is getting reduced. Thus, it is getting reduced and it undergoes reduction reaction. The oxidation state of carbon increases from +2 to +4. Thus, it is getting oxidized and it undergoes oxidation reaction.

Thus, it is considered as redox reaction.

Option B: $CuSO_4+2NaOH\rightarrow Cu(OH)_2+Na_2SO_4$

The above reaction is double displacement reaction because here exchange of ions takes place.

Option C: $2NaOH+H_2CO_3\rightarrow Na_2CO_3+2H_2O$

The above reaction is a neutralization reaction because an acid reacts with base to produce salt and water.

Option D: $Pb(NO_3)2+Na_2SO_4\rightarrow 2NaNO_3+PbSO_4$

The above reaction is double displacement reaction because here exchange of ions takes place.

Hence, the correct answer is Option A.

Answer 2

A) Fe⁺³₂O₃ + 3C⁺²O -> 2Fe⁰ + 3C⁺⁴O₂