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Ted Mooney, P.E. RET
Pine Beach, NJ

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Confusion on chromate treatment for Cadmium

Is there a difference between cadmium dichromate and cadmium bichromate as my customer is specifying cadmium bichromate but my plater is telling me he has been supplying me with cadmium dichromate? Is it a difference in the chain structure of the compound as I interpret both to be Cr2 compounds (Cr2O7?) If there is a chemical difference, is there a performance difference?

Ed Chung
product designer - Toronto, ON, Canada
November 12, 2009

November 13, 2009

Hi, Ed. To my knowledge this is just confusion in the nomenclature and they are just two names for the same thing.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

The customer is using a prostituted word. Yours is the correct one. In chemistry, the bi in front of chromate would indicate that there was a hydrogen ion where the bi is. Think of sodium bicarbonate NaHCO3.
I am not aware of a bichromate being commercially available. The confusion results from bi normally meaning "2" In chemistry that is done with a "di".

James Watts
- Navarre, Florida
November 13, 2009

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