Question

Calculate the average oxidation number of underlined element in the following compound:
$\underset{---}{M{n}_3}{O}_4$

• A. $+\frac{1}{2}$
• B. $+\frac{8}{3}$
• C. $\frac{5}{2}$
• D. $\frac{7}{3}$

Answer 1

The correct option is B $+\frac{8}{3}$

Let oxidation state of Mn is $x$.
Charge of O = -2
$3x-8=0$
$\Rightarrow 3x=8\Rightarrow x=+\frac{8}{3}$
$\therefore \text{average oxidation number of Mn is}+\frac{8}{3}$