Question

The oxidation number of $Cr$ in $Cr{O}_5$ which has the following structure is

• A. $+4$
• B. $+5$
• C. $+6$
• D. $+3$

Answer 1

Answer: (C)

It has four $O$ atoms as peroxide with oxidation number $=-1$ and one $O$ atom with oxidation number $=-2$.
Hence, $x+4(-1)+1(-2)=0$ or $x=+6$