Question

Give the oxidation state of underlined.
$\underset{–}{Cr}{O}_5$.

Answer 1

By looking the above structure we can observe that 4 oxygen atoms are linked by peroxide linkage.So their oxidation state is -1 as in peroxide.

One oxygen atom is attached normally so its oxidation state is -2.

So oxidation state of $Cr$ is$x+4(-1)+(-2)=0,x=+6$.