Question

Write the different oxidation states of iron. Why is the +2 oxidation state of manganese more stable? (Z of Mn = 25)

Answer 1

Hint: The oxidation state of an atom also referred to as the oxidation number of a chemical compound which provides the information about the number of electrons lost and also describes the extent of oxidation of the atom.

Complete answer: The oxidation state of an atom can also be defined as the hypothetical charge held by an atom when all of its bonds to other atoms are completely ionic in nature. Oxidation state can be zero, positive or negative.
Oxidation states of iron: Iron is a chemical element having atomic number 26. Iron represents the symbol Fe. It is the most common element found on the earth. Electronic configuration of iron can be classified as: $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}4{{s}^{2}}3{{d}^{6}}$. Compounds of iron are mainly formed at +2 and +3 oxidation states. In case of +2 oxidation state it loses electrons from 4s subshell and in case of +3 it form exactly half filled subshell of $3{{d}^{5}}$ and it also occurs at higher oxidation state + 6.
Manganese is represented by the symbol Mn having atomic number 25. The electronic configuration of Mn is shown as: $1{{s}^{2}}2{{s}^{2}}2{{p}^{6}}3{{s}^{2}}3{{p}^{6}}4{{s}^{2}}3{{d}^{5}}$. Most common oxidation states shown by manganese are +2, +3, +4, +6 and +7 through all oxidation states from −3 to +7 have been observed. But the most common oxidation state shown by Mn is +2 as it gives exactly half-filled stable configuration.

Note: The oxidation state of an atom is not termed as the real charge of the atom. In a chemical reaction if there is an increase in oxidation state then it is known as oxidation and if there is a decrease in oxidation state then it is known as reduction.