Question

Number of peroxy linkage in $K_{3}Cr{\left(O_2\right)}_x$ having oxidation number of $Cr$ as $+5$ is :

Answer 1

Let $x$ be the number of peroxy linkage in $K_{3}Cr(O_2{)}_x$.
The sum of the oxidation numbers of all atoms in neutral molecule is zero.
Therefore, $3(+1)+5+x(-2)=0$
Hence, $x=4$
Hence, the number of peroxy linkage in $K_{3}Cr{\left(O_2\right)}_x$ having oxidation number of $Cr$ as $+5$ is $4$.