Properties of copper oxide

Copper oxide has the following properties:
1. Physical properties
1. Appearance and color: Usually black to brown black powder or particles.
2. Density: The density is about 6.3-6.9g/cm³, and the density of different crystal types is slightly different, such as 6.40 for cubes and 6.45 for triclinic crystals.
3. Solubility: insoluble in water and ethanol, soluble in acid, ammonia, ammonium salt, potassium cyanide solution, etc. It dissolves slowly in ammonia, but becomes easier in the presence of ammonium salts such as ammonium chloride, ammonium sulfate, ammonium sulfide, or ammonium carbonate.
4. Melting point and thermal stability: the melting point is about 1026 ° C, and the thermal stability is good. It will not decompose under general heating conditions, but it will decompose into cuprous oxide and oxygen at high temperatures.
5. Hygroscopicity: slightly hygroscopicity, it may absorb a certain amount of water when placed in the air.
6. Hardness: The hardness is 3-4.
7. Electrical and thermal conductivity: It has certain electrical and thermal conductivity, and can be used as electrode materials, thermoelectric components, etc.
Second, chemical properties
1. Properties of basic oxides: can react with acid to produce salt and water, such as copper oxide and sulfuric acid reaction to produce copper sulfate and water, reaction with hydrochloric acid to produce copper chloride and water.
2. Oxidation: It is oxidizing and can be REDOX with reducing agents under heating conditions, such as hydrogen, carbon, carbon monoxide and more electronegative metals, etc., to be reduced to copper metal or cuprous oxide, while copper oxide can oxidize organic gases to carbon dioxide and water.
3. High-temperature decomposition reaction: At high temperatures, decomposition reactions occur to generate copper or cuprous oxide, and release oxygen.
4. Reaction with sulfur dioxide: It can react with sulfur dioxide in the flue gas, such as in the supported CuO desulfurization and denitrification technology, CuO/Al₂O₃ is the desulfurization adsorbent, absorbs SO₂ and catalyzes it to CuSO₄.
Third, amphoteric nature: slightly amphoteric, can react with a strong base, but the degree of reaction is relatively weak