Cuprous Chloride forms compounds in the oxidation state […]
Cuprous Chloride forms compounds in the oxidation states of +1 (cuprous) and +2 (cupric); trivalent copper survives no more than a few seconds in an aqueous solution. The relatively small change in electrochemical potential between the cuprous and cupric ions in solution gives the usefulness of copper compounds in chemical reactions. Copper compounds are used as catalysts in reactions, especially oxidation (cupric chloride) and heterogeneous reactions. Cupric chloride, copper chloride (CuCl2) is yellowish to brown, deliquescent powder; soluble in water, alcohol, and ammonium chloride; while the dihydrated form of cupric chloride is a green crystal; soluble in water. It is used as a mordant in dyeing and printing textile fabrics and in the refining of copper, gold, and silver as well as a catalyst in chemical reactions.
Cuprous chloride (CuCl or Cu2Cl2), also known as the resin of copper, is a green, tetrahedral crystal; insoluble in water. The biological property of copper compounds takes an important role in as fungicides in agriculture and biocides in antifouling paints for ships and wood preservations. Very low level of copper is toxic to fungi and algae but the levels for a mammal is much higher. The copper ions inhibit the metabolism of the fungus when they react with sulfur-containing enzymes in the plant. Copper compounds form a protective barrier on the plant surface and thereby prevent fungi from entering the plant host. The fungicidal effect of copper compounds as non-systemic fungicides are such as Bordeaux mixture, cupric hydroxide, copper arsenate, copper carbonate, cuprous oxide, copper-8-quinolinolate, copper oleate, copper sulfate, or copper oxychloride. Another important biological application of copper compounds, such as copper sulfide is as an antifouling agent in paints.