Chromate salts contain the chromate anion, CrO42−. Dichromate salts contain the dichromate anion, Cr2O72−. They are oxoanions of chromium in the oxidation state +6. They are moderately strong oxidizing agents.
From wikipedia
It goes on to say that all hexavalent chromium compounds are toxic due to their oxidizing power and that the use of chromate compounds in manufacturing goods has been banned in Europe.
May want to be careful with that.
Bookmarks