What are the sulfur oxidation states in sulfuric acid and sulfurous acid?

1 Answer
Aug 26, 2017

Answer:

For #H_2SO_4# we gots #S(VI)#.

Explanation:

For #H_2S_2O_3# we gots #S_"average"(II)#. As always the sum of the oxidation is equal to the charge on the ion/molecule, here neutral.

For #H_2S_2O_3# I like to think that ONE of the oxygens in #H_2SO_4# has been REPLACED by a sulfur atom, and thus assumes the SAME oxidation state (they are both Group VI elements). And so, by this formalism, we gots #S(-II)# and #S(+VI)#.

Of course the average oxidation state is ......

#(S(-II)+S(+VI))/2=+II#,

.........but sometimes the individual assignment of oxidation numbers in poly-sulfur compounds is useful.