Copper(II) oxide

Copper(II) oxide (CuO) is an inorganic compound that is a black solid. It is one of the two stable copper oxides, the other being copper(I) oxide (Cu2O). Copper(II) oxide is a basic oxide, which means it reacts with acids to form salts and water. It is used in various applications, including as a pigment in ceramics to produce blue, red, and green (and sometimes black) colors, in the manufacture of glass, as a precursor in the production of copper salts, and in the fabrication of semiconductor devices.

Properties

Copper(II) oxide is a black crystalline solid with a monoclinic crystal structure. Its molecular weight is 79.545 g/mol, and it has a melting point of 1,326 °C (2,419 °F). Being an oxide of copper, it reacts with sulfuric acid to form copper sulfate, a blue-green solid that is widely used in agriculture and industry.

Synthesis

Copper(II) oxide can be produced by the pyrometallurgical process of oxidizing copper metal at high temperature, in the presence of air. This process involves heating copper in a furnace, where it reacts with oxygen to form CuO. Alternatively, it can be synthesized chemically by the controlled addition of a strong oxidizing agent to a solution of a copper(II) salt, such as copper sulfate.

Applications

Ceramics

In the ceramics industry, copper(II) oxide is used as a pigment to produce colors ranging from deep blue to green and red. It is also used to create black glazes when combined with other compounds.

Glass

Copper(II) oxide is used in the production of glass, where it imparts a range of colors depending on the concentration and the presence of other chemicals in the glass mix.

Copper Salts

The compound is a starting material for the production of other copper-containing chemicals, such as copper(II) acetate and copper(II) carbonate.

Semiconductors

Due to its semiconductor properties, CuO is used in the fabrication of semiconductor devices, including solar cells and sensors.

Safety

Copper(II) oxide is considered hazardous and can cause irritation when in contact with skin or eyes. Inhalation of its dust can lead to respiratory tract irritation. Proper safety equipment, such as gloves and masks, should be used when handling this chemical.

Environmental Impact

Copper compounds, including copper(II) oxide, can be toxic to aquatic life and should be handled and disposed of with care to prevent environmental contamination.