In mildly alkaline medium, thiosulphate ion is oxidized by $$MnO_4^-$$ to 'A'. The oxidation state of sulphur in 'A' is ______

In mildly alkaline medium, the permanganate ion ($$MnO_4^-$$) acts as an oxidizing agent. The thiosulphate ion ($$S_2O_3^{2-}$$) is oxidized to sulphate ion ($$SO_4^{2-}$$) in alkaline conditions.

In the thiosulphate ion $$S_2O_3^{2-}$$, the average oxidation state of sulphur is +2. In mildly alkaline medium, permanganate is a strong enough oxidizer to convert thiosulphate completely to sulphate.

In the sulphate ion $$SO_4^{2-}$$, let the oxidation state of sulphur be $$x$$. Then $$x + 4(-2) = -2$$, giving $$x = +6$$.

Therefore, the product 'A' is $$SO_4^{2-}$$ and the oxidation state of sulphur in 'A' is $$6$$.