Why do you wash the basin with water?
Not all copper. Is alloy, with the air water chemical reaction.
Treatment: CuO + 2H + = Cu2 + + H2O, indicating that CuO can react with H + (method: black washbasin surface coated with acetic acid, and then wipe with a scouring pad, and finally rinse with water).
Chemical Reaction Equation: 2Cu + O2 = Heating => 2CuO
Reason: long time with copper wash basin, because a long time exposure to hot water and oxygen, resulting in copper and oxygen reaction to produce copper oxide, copper oxide is black, attached to the surface of the basin, so the basin black.
