Question

Oxidation number of sulphur in $N{a}_2{S}_2{O}_3$ would be :

• A. +4
• B. +2
• C. -2
• D. 0

Answer 1

The correct option is B +2

${Na}_2{S}_2{O}_3\Rightarrow$

Oxidation number of $S_1=-2$

Oxidation number of $S_2=+1+1+2+2=+6$

Average oxidation number of $S=\frac{-2+6}{2}=+2$