Question

Find oxidation number of Sulphur in $H_2{S}_4{O}_6$.

Answer 1

Oxidation number of $S_1=+2+1+2=+5$

Oxidation number of $S_2=0$

Oxidation number of $S_3=0$

Oxidation number of $S_4=+2+1+2=+5$

Average oxidation number of $S=\frac{+5+5+0+0}{4}=+\frac{5}{2}$