10 Given the balanced ionic equation representing a reaction:

Zn (s) + Co2 + (aq) → Zn2 + (aq) + Co (s)

Which statement describes the electrons involved in this

reaction?

A) Each Zn atom loses 2 electrons, and each Co2 + ion gains 2

electrons.

B) Each Zn atom loses 2 electrons, and each Co2 + ion loses 2

electrons.

C) Each Zn atom gains 2 electrons, and each Co2 + ion loses 2

electrons.

D) Each Zn atom gains 2 electrons, and each Co2 + ion gains 2

electrons.

Option (A) Each Zn atom loses 2 electrons, and each Co2 + ion gains 2

Explanation:

To know the right answer to the question, let us observe the changes in the oxidation number of Zn and Co. This is illustrated below:

Zn (s) + Co2 + (aq) → Zn2 + (aq) + Co (s)

The oxidation number of Zn changes from 0 to + 2 indicating that Zn has lose 2 electrons.

The oxidation number of Co changes from + 2 to 0 indicating that Co has gain 2 electrons.

Therefore, option A is the correct answer.