What is "carbon dioxide"

Carbonic \Car*bon"ic\, a. [Cf. F. carbonique. See Carbon.] (Chem.) Of, pertaining to, or obtained from, carbon; as, carbonic oxide.

Carbonic acid (Chem.), an acid HO.CO.OH, not existing separately, which, combined with positive or basic atoms or radicals, forms carbonates. In common language the term is very generally applied to a compound of carbon and oxygen, CO2, more correctly called carbon dioxide. It is a colorless, heavy, irrespirable gas, extinguishing flame, and when breathed destroys life. It can be reduced to a liquid and solid form by intense pressure. It is produced in the fermentation of liquors, and by the combustion and decomposition of organic substances, or other substances containing carbon. It is formed in the explosion of fire damp in mines, and is hence called after damp; it is also know as choke damp, and mephitic air. Water will absorb its own volume of it, and more than this under pressure, and in this state becomes the common soda water of the shops, and the carbonated water of natural springs. Combined with lime it constitutes limestone, or common marble and chalk. Plants imbibe it for their nutrition and growth, the carbon being retained and the oxygen given out.

Carbonic oxide (Chem.), a colorless gas, CO, of a light odor, called more correctly carbon monoxide. It is almost the only definitely known compound in which carbon seems to be divalent. It is a product of the incomplete combustion of carbon, and is an abundant constituent of water gas. It is fatal to animal life, extinguishes combustion, and burns with a pale blue flame, forming carbon dioxide.

1869, so called because it consists of one carbon and two oxygen atoms. The chemical was known since mid-18c. under the name fixed air; later as carbonic acid gas (1791). "The term dioxide for an oxide containing two atoms of oxygen came into use in the middle of the 19th century." [Flood].

n. (context inorganic compound English) The normal oxide of carbon, CO₂; a colorless, odorless gas formed during respiration and combustion and consumed by plants during photosynthesis.

n. a heavy odorless colorless gas formed during respiration and by the decomposition of organic substances; absorbed from the air by plants in photosynthesis [syn: CO2, carbonic acid gas]

This page provides supplementary chemical data on carbon dioxide.

Carbon dioxide ( chemical formula CO) is a colorless and odorless gas vital to life on Earth. This naturally occurring chemical compound is composed of a carbon atom covalently double bonded to two oxygen atoms. Carbon dioxide exists in Earth's atmosphere as a trace gas at a concentration of about 0.04 percent (400 ppm) by volume. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, in ice caps and glaciers and also in seawater. It is present in deposits of petroleum and natural gas.

Atmospheric carbon dioxide is the primary source of carbon in life on Earth and its concentration in Earth's pre-industrial atmosphere since late in the Precambrian was regulated by photosynthetic organisms and geological phenomena. As part of the carbon cycle, plants, algae, and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water, with oxygen produced as a waste product.

Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrate and lipids to produce energy by respiration. It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals, including humans. Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread, beer and winemaking. It is produced by combustion of wood, carbohydrates and fossil fuels such as coal, peat, petroleum and natural gas.

It is a versatile industrial material, used, for example, as an inert gas in welding and fire extinguishers, as a pressurizing gas in air guns and oil recovery, as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying. It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence. The frozen solid form of CO, known as " dry ice" is used as a refrigerant and as an abrasive in dry-ice blasting.

Carbon dioxide is an important greenhouse gas. Since the Industrial Revolution, anthropogenic emissions - including the burning of carbon-based fossil fuels and land use changes (primarily deforestation) - have rapidly increased its concentration in the atmosphere, leading to global warming. It is also a major cause of ocean acidification because it dissolves in water to form carbonic acid.