Carbon dioxide | Definition, Formula, properties, Uses, & Effects

Carbon dioxide

It is a colorless gas that has a density of about 60% higher than dry air. Its chemical formula is CO2. Carbon dioxide consists of a carbon atom that is double bonded to two oxygen atoms collectively. It occurs naturally as a trace gas in the Earth’s atmosphere. The current concentration increased by 0.04% (412 ppm) by volume, from the pre-industrial level of 280 ppm. Natural resources include volcanoes, hot springs, and geysers, and it is liberated from carbonate rocks by dissolving in water and acid. Since CO2 is water-soluble, it occurs naturally in groundwater, rivers, glaciers and other water bodies. It is present in petroleum and natural gas reserves. Carbon dioxide is generally odorless at concentrations encountered, but at high concentrations, it has a sharp and acidic aroma. At such concentrations, it produces a taste of soda water in the mouth.

Carbon dioxide

Source of Carbon dioxide

As a source of carbon dioxide available in the carbon cycle, atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in the Earth’s pre-industrial environment from the end of the Precambrian is controlled by photosynthesis and geological phenomena. Plants, algae, and cyanobacteria use carbon dioxide and carbohydrates from water as energy for photosynthesis, producing oxygen as a waste product.

Carbon dioxide emissions by source is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy through respiration. It returns to the water through the fish’s gills and to the air through the lungs of air-breathing land animals, including humans. CO2 is produced during the decay of organic matter. It is produced by combustion of wood and other organic matter and fossil fuels such as coal, peat, petroleum and natural gas.

Industrial Use of Carbon dioxide

It is a versatile industrial material, for example, used as an inert gas in welding and combustion engines, as a compressor gas in air guns and oil recovery, as a chemical feedstock and as a supercritical fluid solvent in coffee and supercritical drying. It is paired with beer and sparkling wine for drinking water and carbonated drinks. A condensed solid form of CO2

Dry Ice 2 is used as a coolant and as friction in a dry-ice explosion. It is the feedstock for the synthesis of fuels and chemical uses of co2.

Use of Carbon dioxide

Green House effect

CO2 is a very important greenhouse gas in the atmosphere. The Industrial Revolution’s anthropogenic emissions – mainly from the use of fossil fuels and deforestation – rapidly increased its concentration in the atmosphere, leading to global warming. Carbon dioxide natural greenhouse gases also causes ocean acidification because it dissolves in water and forms carbonic acid.

Green House effect

Carbon dioxide Structure and bonding

The carbon dioxide molecule is linear and centrosymmetric. The carbon-oxygen bond length is 116.3 pm, which is much shorter than the bond length of the C – O single bond and shorter than that of the other C – O multiplication-bonded functional groups. Because it is centrosymmetric, the molecule does not have an electric dipole. Consequently, only two vibrational bands are observed in the IR spectrum – the antisymmetric stretching mode at wavelength 2349 cm – 1 and the paired bending modes at 667 cm – 1 (wavelength 15 μm). By Raman spectrum we observed the its internal structure whose symmetric stretching mode at 1388 cm – 1.

Carbon dioxide Structure and bonding

Physical properties

Carbon dioxide is colorless. At low concentrations it is odorless gas; but at suitably high concentrations, it has a very sharp acidic aroma.  At STP, the concentration of CO2 is 1.98 kg / m3, 1.67 times that of air.

Carbon dioxide 5.1 does not have a liquid state at a pressure lower than the standard atmosphere (520 kPa).

Liquid carbon dioxide occurs only at pressures above 5.1 atm; The triple point of carbon dioxide is 211 K at 5.1 bar (517 kPa) (see phase diagram). The critical point is 31.1 at C at 7.38 MPa. Another form of solid CO2 observed at high pressure is an amorphous form of glass-like solid. This glass form, called carbonia, is produced by super cooling heated CO

2 at high pressure in diamond anvil (40–48 GPa or about 400,000 atmospheres). This invention confirms the theory that carbon dioxide is in the same glass state as other members of its original family, such as silicon and germanium dioxide.

At temperatures and pressures above the critical point, carbon dioxide supercritical behaves as a supercritical liquid called carbon dioxide. It is in this state that electricity is beginning to be used (as of 2018).