There are two ways for determining an atom’s oxidation number in a molecule or ion, and we’ll use both to determine the oxidation number of KMnO4.
We will use known oxidation numbers in the molecule to find an unknown oxidation number of an atom in the same molecule using the algebra approach.
Oxidation number of K +4 4 (oxidation number of oxygen) + oxidation number of Mn +=0
Find oxidation number of Manganese in KMnO4 from algebra method
In algebra method, we are going to use known oxidation numbers in the molecule to find out unknown oxidation number of an atom in the same molecule.
Oxidation number of K + 4 × (oxidation number of oxygen) + oxidation number of Mn = 0
Lets take oxidation number of Manganese atom as x.
The Oxidation number of manganese in KMnO4 is +7.
Find oxidation number of Manganese by observing the lewis structure of KMnO
First, we have to draw the best lewis structure of KMnO4.
Then, we can find the Oxidation number due to bonds and Oxidation number due to charge using the lewis structure.
Oxidation number due to bonds: there are three double bonds and one single bond around manganese with oxygen atoms. Oxygen is more electronegative than manganese. Therefore, electrons in the bonds are attracted towards the oxygen atoms. Manganese gives seven electrons for these bonds. So, manganese atom losses 7 electrons and get (+7) oxidation number due to bonds.
Oxidation number due to charge: in KMnO4 molecule manganese atom has no charge. So, oxidation number due to charge is zero.
Overall oxidation number = Oxidation number due to bonds + Oxidation number due to charge
Overall oxidation number of Mn in KMnO4 = +7
Oxidation number of K +4 4 (oxidation number of oxygen) + oxidation number of Mn +=0
There are two ways for determining an atom’s oxidation number in a molecule or ion, and we’ll use both to determine the oxidation number of KMnO4.
We will use known oxidation numbers in the molecule to find an unknown oxidation number of an atom in the same molecule using the algebra approach.
