Question

In the following reaction that takes place in batteries, which element is being reduced?

1) Zinc
2) Manganese
3) The oxygen in MnO₂
4) The oxygen in water
5) The hydrogen in water

Answer 1

In the redox reaction within a dry cell battery, manganese (IV) is reduced as it transitions from manganese (IV) oxide (MnO₂) to manganese (III) oxide (Mn₂O₃).

Step-by-step explanation:

In the redox reaction that takes place in dry cell batteries, manganese (IV) is the element being reduced. The reduction reaction is shown as 2MnO₂ (s) + 2NH₄Cl(aq) + 2e⁻ → Mn₂O₃ (s) + 2NH₃(aq) + H₂O(l) + 2Cl⁻.

This indicates that manganese (IV) oxide (MnO₂) is gaining electrons during the reaction, transitioning to manganese (III) oxide (Mn₂O₃), and thus being reduced.

As a result, the element being reduced is manganese (IV) in MnO₂.