Question

Fractional values of oxidation numbers are possible as in $\underset{I}{N{a}_2{S}_4{O}_6},\underset{II}{F{e}_3{O}_4},\underset{III}{N_{3}H}$

• A. Only $I$
• B. Only $II$
• C. $I$ and $III$
• D. $I,II$ and $III$

Answer 1

The correct option is D $I,II$ and $III$

$N{a}_2{S}_4{O}_6\text{Let average oxidation number of S be x.}2\times 1+4x+6(-2)=0\Rightarrow 2+4x-12=0\Rightarrow 4x=10\Rightarrow x=+2.5\text{Average oxidation number of S is +2.5.}$

$F{e}_3{O}_4\text{Let average oxidation number of Fe be x.}3\times x+4\times (-2)=0\Rightarrow 3x-8=0\Rightarrow 3x=8\Rightarrow x=+\frac{8}{3}or+2\frac{2}{3}\text{Average oxidation number of Fe is}+2\frac{2}{3}.$

$N_{3}H\text{Let average oxidation number of N be x.}3x+1=03x=-1x=-\frac{1}{3}\text{Average oxidation number of}\text{nitrogen is}-\frac{1}{3}.$