Question

Oxidation state of oxygen in $Cr{O}_5$ is :

• A. -1
• B. -2
• C. Both $A$ and $B$
• D. $-\frac{1}{2}$

Answer 1

The correct option is C Both $A$ and $B$

$Cr{O}_5$ is chromium with four peroxy oxygen and one coordinated oxygen.

It is a butterfly type structure in which central chromium surrounds with 4 peroxy cyclic oxygen and 1 coordinate oxygen. In this, the oxidation number of chromium is +6.

$Cr{O}_5$ has 2 pairs in peroxide. It implies that 4 oxygen is in $-1$ oxidation state and one in $-2$ oxidation state.

Hence, option $\left(C\right)$ is correct.