Carbon dioxide or dioxide are synonymous names for the well-known carbon dioxide. According to the chemical classification, this substance is carbon monoxide (IV), CO2. Under normal conditions, this compound is in a gaseous state, has no color and odor, but has a sour taste. It dissolves in water, forming carbonic (carbonate) acid. A feature of carbon dioxide is that at normal atmospheric pressure (101,325 Pa or 760 mm Hg), it does not exist in a liquid state, but only in the form of a gas or the so-called dry ice. Liquid carbon dioxide can only form if atmospheric pressure is increased. In this form, it can be transported in cylinders and used for its intended purpose: for welding, the production of carbonated drinks, freezing and cooling food and fire extinguishers. This substance is also used as a preservative E 290, a baking powder for dough and a coolant.
Carbon dioxide -acid oxide, therefore, it can interact with alkalis and basic oxides, while forming s alts - carbonates or bicarbonates and water. A qualitative reaction to the determination of CO2 is its interaction with calcium hydroxide. The presence of this gas will be indicated by the cloudiness of the solution and the formation of a precipitate. Some alkali and alkaline earth metals (active) can burn in an atmosphere of carbon dioxide, depriving it of oxygen. Also, carbon dioxide enters into chemical substitution and addition reactions with
organic elements.
It is found in nature and is part of the air shell of the Earth. It is released into the environment by living organisms during respiration, and plants absorb it during photosynthesis and use it in physiological and biochemical processes.
Due to its high heat capacity, in comparison with other gases of the atmosphere, carbon dioxide, when the concentration in the environment increases, leads to its overheating, due to less heat transfer to outer space. A rise in temperature leads to the melting of glaciers and, as a result, climate change on the globe. Scientists have calculated and concluded that green plants can help to solve this problem (in the fight against the greenhouse effect), which are able to absorb much more CO2 than it is emitted now.
Despite the fact that carbon dioxide is involved in the metabolism of plants and animals, its increased content in the atmosphere can causedrowsiness, weakness, headache and even suffocation. To avoid hypercapnia, it is necessary to ventilate the premises, especially in places where a large number of people gather.
Thus, carbon dioxide is an acidic oxide that occurs naturally and is a metabolic product of flora and fauna. Its accumulation in the atmosphere is the trigger of the greenhouse effect. Carbon dioxide, when interacting with water, forms an unstable carbonic acid that can decompose into water and CO2.
