The oxidation state of ##Cr## in chromate ion, ##CrO_4^(2-)##, is ##VI^+##

Chemistry Apr 13, 2022

The oxidation state of ##Cr## in chromate ion, ##CrO_4^(2-)##, is ##VI^+##.

As far as anyone knows, the charge in chromate is localized on the oxygen (i.e ##(O=)_2Cr(-O^-)_2##). Chromic acid, ##H_2CrO_4## (or ##(O=)_2Cr(-OH)_2##), is the precursor; this is a potent oxidant. In each case, the metal oxidation state (##VI^+##) is clear. Note that in this formal representation, the charge on chromium is neutral. The negative charge is borne by the 2 singly bound oxygen atoms.