Question

Calculate the oxidation number of sulphur atom in ${Na}_2{SO}_3$.

Answer 1

Let the oxidation number of sulphur is $x$.

$N{a}_2\stackrel{x}{S}{O}_3$

$2\times (+1)+x+(-2)\times 3=0$

$2+x-6=0$

$x=+4$

Thus, the O.S. of sulphur is +4.