# How do we represent the oxidation of thiosulfate anion, S_2O_3^(2-) to tetrathionite, S_4O_6^(2-)...?

May 27, 2017

$\text{Thiosulfate to tetrathionite...........}$

$2 {S}_{2} {O}_{3}^{2 -} \rightarrow {S}_{4} {O}_{6}^{2 -} + 2 {e}^{-}$ ;stackrel(II)Srarrstackrel(II*1/2)S

#### Explanation:

I always considered $\text{thiosulfate dianion}$, ${S}_{2} {O}_{3}^{2 -}$, to be the same as sulfate dianion, $S {O}_{4}^{2 -}$, EXCEPT that one of the oxygen atoms has been replaced by congeneric sulfur. And this sulfur has PRECISELY the same oxidation state as the oxygen it replaces, i.e. $\stackrel{- I I}{S}$. The AVERAGE oxidation states is still.................................

$\frac{S \left(- I I\right) + S \left(+ V I\right)}{2} = S \left(+ I I\right)$

Anyway, let's try to balance the beast.

$2 {S}_{2} {O}_{3}^{2 -} \rightarrow {\stackrel{}{S}}_{4} {O}_{6}^{2 -} + 2 {e}^{-}$ ;stackrel(II)Srarrstackrel(II*1/2)S

Do you agree that it is balanced with respect to mass and charge?