Question

What is the oxidation state of $Mn$ in $KMn{O}_4$?

• A. 7
• B. 3
• C. -3
• D. -7

Answer 1

The correct option is A 7

Since $KMn{O}_4$ is a stable compound, the sum of the total oxidation number should be zero.
We know that the oxidation number of K(potassium) and O(oxygen) is +1 and -2 respectively.
Let the oxidation number of $Mn$ be $x$ The sum of the oxidation numbers is given by,

$\Rightarrow (+1)+x+4\times (-2)=0$

$\Rightarrow 1+x-8=0$

$\Rightarrow x-7==0$

$\Rightarrow x=7$

So, the oxidation state of $Mn$ in $KMn{O}_4$ is 7.