Carbonic acid: what do we know about it?

Carbonic acid: what do we know about it?
Carbonic acid: what do we know about it?
Anonim

The more a person learns about the world around him, the more he realizes the limitations and imperfections of his knowledge. Take, for example, sparkling water. As you know, this drink differs from others in that it contains carbonic acid in small doses, which immediately begins to decompose as soon as we unscrew the cork on the bottle.

carbonic acid
carbonic acid

Therefore, we have no doubts about the statement in the textbook of chemistry that this substance is extremely unstable. In the gas phase, it very quickly turns into a mixture of ordinary water and the usual carbon dioxide. However, as recent studies have shown, it is quite possible to argue with this. But first, let's remember what this substance is.

What is carbonic acid?

The formula for this chemical compound looks pretty simple: H2CO3, and its instability speaks of its weakness. As is known, dissociation of acids occurs in water, and the compound in question does not fall under the exception. However, there is one feature here: due to the presence of two bases, this process occurs in two stages:

H2CO3 ↔ H+ + NSO3 -,

HSO3- ↔ H+ + CO32-.

When interacting with a strong base, carbonic acid forms normal or acidic carbonates. The latter differ in that they replace not two, but only one hydrogen atom. A prime example of a normal carbonate is washing soda (Na2CO3), and baking soda (NaHCO3).

acid dissociation
acid dissociation

What did scientists discover?

When anhydrous potassium bicarbonate (KHCO3) is protonated at -110oC, hydrogen knocks out a K atom. The result is a very pure carbonic acid. Later, an even easier method was found - heating in vacuum NH4HCO3 As a result of this decomposition of ammonium bicarbonate, ammonium is released and anhydrous carbonic acid is formed. The latter exhibits amazing stability during sublimation in a vacuum. When scientists began to investigate this paradox, it turned out that the reason lies in the meaning of the energy barrier. For an anhydrous compound H2CO3 it is 44 kcal/mol, and when there is water, its value is almost two times lower - 24 kcal /mol. So under appropriate conditions, carbonic acid may well be in a free form. However, this discovery is interesting not only from the point of view of the theory of chemistry. Its practical value lies in the fact that it allowed us to study the process of breathing in a new way. Now scientists believe that the formation of carbonic acid in a living organism is accelerated with the help of a special enzyme, and this is precisely what allows you to quickly remove carbon dioxide from cells, first into the blood, and then into the lungs.

carbonic acid formula
carbonic acid formula

Astronomers also did not fail to take advantage of this discovery: the free state of carbon dioxide allowed them to conduct its spectral analysis, and now this compound can be identified in the atmosphere of the planets surrounding us. All this suggests that the world is still full of various mysteries and secrets. It seems that modern textbooks will have to be rewritten more than once, clarifying old ones and discovering new knowledge.

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