What Is Copper Oxide?
Copper oxide is an oxidized form of copper, existing in two types: copper oxide (I) and copper oxide (II).
Copper oxide (I) is produced by reducing an aqueous solution with Fehling’s solution, while copper oxide (II) is obtained by red heating copper in air.
Uses of Copper Oxide
1. Copper Oxide (I)
Used in rectifiers, red pigments, glazes, fungicides, antifouling paints, and glass coloring. Copper oxide (I) paints on ship bottoms prevent barnacle attachment, enhancing fuel efficiency. It is also used in catalysts for photovoltaics, seed sterilization, synthetic resins, and enzyme production.
2. Copper Oxide (II)
Employed as an oxidizing agent, catalyst, pigment, ceramic glaze, and coloring agent for glass. Known for making phthalocyanine blue pigment, it is also used in semiconductors, plating chemicals, paints, rayon manufacturing, and wood preservatives. In ceramics, it contributes to red coloration when reduction is fired with glaze.
Characteristics of Copper Oxide
1. Copper Oxide (I)
Also known as cuprous oxide, it is a red powder (Cu2O) that oxidizes to copper oxide (II) in humid air. It has a molecular weight of 143.08, a specific gravity of 5.88, and is soluble in hydrochloric acid and ammonia solutions.
2. Copper Oxide (II)
Also known as cupric oxide, it is a black powder (CuO) found in natural black copper ore. It has a molecular weight of 79.55, a specific gravity of 6.31, and is soluble in hydrochloric acid, ammonia solutions, and alkaline hydroxide solutions.
1. Oxidation and Reduction of Copper Oxide
Experiments demonstrate the oxidation and reduction principles of copper oxide. Copper transforms into copper oxide (II) when heated, losing properties like metallic luster and conductivity. Reduction methods include using carbon or hydrogen and reverting it back to metallic copper.
2. Copper Oxide Production Method
Copper Oxide (I) is produced through electrolytic and chemical processes. Copper Oxide (II) is obtained through heat oxidation, chemical processes, and direct or indirect wet processes.