Hello everyone,

 

Please could someone explain something for me? When thiosulphate is oxidised, for example, in the following reaction:

 

I2 + (2S2O3)2- -> 2I- + (S4O6)2-

 

I know the 2 electrons have now gone to the 2 iodine atoms, but what are the individual charges of the atoms in the thiosulphate at product stage?

 

thanks in advance

Gav

 

the only reason I ask is because in working it out, at product stage we have (2S2O3)1- + 1e-. As oxygen is 2- each, totaling 6-, and the total charge is 1-, I figured the S would have to total 5-, but that would entail one being 3+ and the other being 2+. I only thought sulphur could be 6+, 4+, 0 or 2-.

Does this help?

http://en.wikipedia.org/wiki/Tetrathionate

the sulphurs at the ends are 6 valent.

thanks for that John, it explainms it very clearly.