Question

Calculate average oxidation number of $S$ in $S_4{O}_6^{2-}$ respectively.

• A. $2.5$
• B. $2$
• C. $3$
• D. $6$

Answer 1

The correct option is A $2.5$


Charge on oxygen atom is $=-2$

Let oxidation number of S-atom in $S_4{O}_6^{2-}$ is $x$
$\therefore \left(x\right)\times 4+(-2)\times 6=-2\Rightarrow x=+2.5$
There are four S-atoms in $S_4{O}_6^{2-}$ However, two sulphur atoms that are linked to each other are having $0$ oxidation number , whereas other two sulphur atoms have $+5$ oxidation number. Overall we get average oxidation number by calculation to be $2.5$