Question

Give the oxidation state of underlined.
$N{a}_2\underset{–}{S_2}{O}_3$.

Answer 1

Let the oxidation number of $S$ in ${Na}_2{S}_2{O}_3$ be x. The oxidation states of $Na$ and $O$ are +1 and -2 respectively. Since the atom as whole is neutral, following equation holds true:

$2\times (+1)+2\times \left(x\right)+3\times (-2)=0⟹2+2x-6=0⟹2x=6-2⟹x=\frac{4}{2}=+2$

Hence, oxidation state of S is +2.