Carbon dioxide (CO2) is a gas with a subtle sour taste that has neither color nor smell. Its concentration in the Earth's atmosphere averages about 0.04%. On the one hand, it is absolutely unsuitable for sustaining life. On the other hand, without carbon dioxide, all vegetation would simply die, since it is it that serves as a “food source” for plants. In addition, for the Earth CO2 is a kind of blanket. Without this gas in the atmosphere, our planet would become much cooler, and the rains would almost completely stop.
Earth Blanket
The formation of carbon dioxide (carbon dioxide, CO2) occurs as a result of the combination of its two components: oxygen and carbon. This gas is formed wherever coal or hydrocarbon compounds are burned. It is also released during the fermentation of liquids and as a product of respiration.animals and people. To date, the properties of carbon dioxide are well studied. It is known that this gas is heavier than air and colorless. When combined with water, it forms carbonic acid, which is widely used in all kinds of carbonated drinks.
Why do scientists often say CO2 is our planet's blanket? The fact is that carbon dioxide freely passes ultraviolet rays coming to us from space, and reflects infrared waves emitted by the Earth. Therefore, the sudden disappearance of this gas from the atmosphere would primarily affect the climate. However, the likelihood of such a catastrophe is practically zero, since the burning of wood, natural gas, coal and oil gradually increases the concentration of carbon dioxide in the atmosphere. And now it is worth fearing not so much a cold snap as mass melting of glaciers at the poles and an increase in the level of the World Ocean …
Dry ice
In the liquid state, this gas is stored in cylinders with high pressure (approximately 70 atm). If you open the valve of such a steel vessel, snow will begin to escape from the hole. What are miracles? This fact is explained quite simply. When compressing carbon dioxide, work is expended, which in its magnitude is significantly less than that required for its expansion. To compensate for the emerging shortage of CO2cools sharply and turns into "dry ice". Compared to ordinary ice, it has a number of serious advantages: firstly, its evaporation occurs completely, without the formation of residues. BUTsecondly, the "cooling capacity" of dry ice per unit weight is twice as high.
Application
Carbon dioxide is quite often used as an inert medium in wire welding. However, at high temperatures, it decomposes with the release of oxygen oxidizing the metal. Therefore, deoxidizers such as silicon and manganese are added to the welding wire. Canned carbon dioxide is widely used in airguns and in aeromodelling. Liquid gas is used as a fire extinguisher and for the manufacture of lemonade and soda. In addition, carbon dioxide CO2 is also used as a food additive (code E290). And as a well-known means for loosening the dough. And besides, solid carbon dioxide is widely used for food preservation.
