Carbon dioxide (CO2) is a chemical compound composed of molecules with one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature and is the primary carbon source for life on Earth. In the air, CO2 is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is soluble in water and is found in groundwater, lakes, ice caps, and seawater. When carbon dioxide dissolves in water, it forms carbonate and mainly bicarbonate (HCO-3), which causes ocean acidification as atmospheric CO2 levels increase. Atmospheric CO2 concentration has risen from pre-industrial levels of 280 ppm, with burning fossil fuels being the primary cause of increased CO2 concentrations and climate change. The concentration in Earth's pre-industrial atmosphere was regulated by organisms and geological phenomena, with plants, algae, and cyanobacteria using sunlight energy to synthesize carbohydrates from carbon dioxide and water in a process called photosynthesis. Oxygen is consumed, and CO2 is released as waste by all aerobic organisms when they metabolize organic compounds to produce energy by respiration. CO2 is released from organic materials when they decay or combust, such as in forest fires. Carbon dioxide is 53% more dense than dry air but is long-lived and thoroughly mixes in the atmosphere. About half of excess CO2 emissions to the atmosphere are absorbed by land and ocean carbon sinks, which can become saturated and volatile due to decay and wildfires. CO2 is eventually sequestered in rocks and organic deposits like coal, petroleum, and natural gas. Sequestered CO2 is released into the atmosphere through burning fossil fuels or naturally by volcanoes, hot springs, geysers, and when carbonate rocks dissolve in water or react with acids. CO2 is a versatile industrial material, used as an inert gas in welding and fire extinguishers, as a pressurizing gas in air guns and oil recovery, and as a supercritical fluid solvent in decaffeination of coffee and supercritical drying. It is a byproduct of fermentation of sugars in bread, beer, and wine making, and is added to carbonated beverages like seltzer and beer for effervescence. In the gas phase, carbon dioxide molecules undergo significant vibrational motions and do not keep a fixed structure. However, in a Coulomb explosion imaging experiment, an instantaneous image of the molecular structure can be deduced, revealing that none of the molecules in the gas phase are ever exactly linear. This counter-intuitive result is trivially due to the fact that the nuclear motion volume element vanishes for linear geometries, which is true for all molecules (except diatomics).
The CAS Number of Carbon Dioxide is 124-38-9
The Molecular Formula of Carbon Dioxide is CO2
The Molecular Mass of Carbon Dioxide is 44.01
The SMILES Notation of Carbon Dioxide is O=C=O
The InChI Notation of Carbon Dioxide is InChI=1S/CO2/c2-1-3