MCQ Detailed View

Manganese (Mn) is a transition metal with atomic number 25 and electronic configuration [Ar] 3d⁵ 4s². Because it has five electrons in the 3d subshell and two electrons in the 4s subshell, manganese can show a wide range of oxidation states from +2 to +7. This variability arises due to the small energy difference between 3d and 4s orbitals, which allows manganese to lose different numbers of electrons depending on the compound formed.

The most common oxidation state of manganese is +2, as in MnCl₂, which results from the loss of two 4s electrons. Higher oxidation states occur when manganese also loses electrons from the 3d orbitals. Among these, the highest possible oxidation state is +7, which is achieved when all five 3d electrons and two 4s electrons are removed.

The most well-known example of manganese in the +7 oxidation state is potassium permanganate (KMnO₄). In this compound, manganese has an oxidation number of +7, and the ion MnO₄⁻ acts as a powerful oxidizing agent. Another example is manganese heptoxide (Mn₂O₇), where manganese is also in the +7 state. These compounds are strongly oxidizing because manganese in +7 is highly electron-deficient and tends to gain electrons to return to lower, more stable oxidation states.

Lower oxidation states of manganese (+2, +3, +4, +6) are also observed in compounds such as MnO, Mn₂O₃, MnO₂, and MnO₃. However, none exceed +7. Thus, the maximum oxidation state of manganese is +7, which highlights its versatility among transition metals.

This property of manganese is important in redox chemistry, analytical chemistry, and industrial applications, especially in the use of KMnO₄ as a disinfectant and oxidizing agent.