Question

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

Answer 1

`"Thiosulfate to tetrathionite..........."`

`2S_2O_3^(2-) rarr S_4O_6^(2-)+2e^(-)` `;stackrel(II)Srarrstackrel(II*1/2)S`

Explanation:

I always considered `"thiosulfate dianion"`, `S_2O_3^(2-)`, to be the same as sulfate dianion, `SO_4^(2-)`, EXCEPT that one of the oxygen atoms has been replaced by congeneric sulfur.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(-II)S`. The AVERAGE oxidation states is still.................................

`(S(-II)+S(+VI))/2=S(+II)`

Anyway, let's try to balance the beast.

`2S_2O_3^(2-) rarr stackrel()S_4O_6^(2-)+2e^(-)` `;stackrel(II)Srarrstackrel(II*1/2)S`

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