Carbon dioxide, its physicochemical properties and significance

Carbon dioxide, or dioxide, is synonymous with well-known carbon dioxide. According to the chemical classification, this substance is carbon monoxide (IV), CO ₂ . Under normal conditions this compound is in the gaseous state, has no color and odor, but has an acidic taste. It dissolves in water, forming a carbon (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 the liquid state, but only in the form of gas or so-called dry ice. Carbon dioxide liquid can be formed only if the atmospheric pressure is increased. In this form it can be transported in cylinders and used for the purpose: for welding, production of carbonated beverages, freezing and cooling food products and fire extinguishers. This substance is used and as a preservative E 290, baking powder for dough and refrigerant.

Carbon dioxide is an acid oxide, so it can react with alkalies and basic oxides, forming salt-carbonates or hydrogen carbonates and water. A qualitative reaction to the determination of CO ₂ is its interaction with calcium hydroxide. The presence of this gas will be indicated by the turbidity of the solution and the formation of a precipitate. Some alkali and alkaline earth metals (active) can burn in an atmosphere of carbon dioxide, taking away oxygen from it. Carbon dioxide also enters chemical substitution and addition reactions with Organic elements.

Occurs in nature and is a part of the Earth's air envelope. In the environment it is isolated by living organisms during respiration, and its plants are absorbed in photosynthesis and used in physiological and biochemical processes.

Because of its high heat capacity, compared to other gases of the atmosphere, carbon dioxide when the concentration in the environment increases leads to its overheating, due to the lower heat transfer to outer space. A rise in temperature leads to the melting of glaciers and, as a consequence, climate change on the globe. Scientists have calculated and concluded that green plants can help solve this problem (in the fight against the greenhouse effect), which are able to absorb much more CO2 than it is being emitted now.

Despite the fact that carbon dioxide takes part in the metabolism of plants and animals, its increased content in the atmosphere can cause drowsiness, weakness, headache and even choking. In order to avoid hypercapnia, it is necessary to ventilate the rooms, especially in places where a large number of people are gathered.

Thus, carbon dioxide is an acidic oxide, which is found in nature and is a product of the metabolism of representatives of flora and fauna. Its accumulation in the atmosphere is the triggering mechanism of the greenhouse effect. Carbon dioxide, when reacted with water, forms an unstable carbonic acid that can decompose into water and CO2.