Amongst the following identify the species with an atom in + 6 oxidation state:
In MnO−4, Mn is in +7 oxidation state.
Likewise, in Cr(CN)3−6 Chromium exhibits +3 oxidation state.
As for NiF2−6, Nickel shows +4 oxidation state.
What will be the oxidation number of Cr in CrO2Cl2?
We apply the rules for assigning oxidation number: