Calcium… What do you know about it? "It's metal" - and only answer many. What calcium compounds exist? With this question, everyone will start scratching their heads. Yes, there is not much knowledge about the latter, and about calcium itself too. Okay, we'll talk about it later, but today let's look at at least three of its compounds - calcium carbonate, hydroxide and calcium bicarbonate.
1. Calcium carbonate
He is a s alt formed by calcium and carbonic acid residue. The formula of this carbonate is CaCO3.
Properties
It has the appearance of a white powder, insoluble in water and ethyl alcohol.
Obtaining calcium carbonate
It is formed by the calcination of calcium oxide. Water is added to the latter, and then carbon dioxide is passed through the resulting calcium hydroxide solution. The reaction products are the desired carbonate and water, which are easily separated from each other. If it is heated, splitting will occur, the products of which will be carbon dioxide and quicklime. By dissolving this carbonate and carbon monoxide (II) in water, calcium bicarbonate can be obtained. If you combine carbon and calcium carbonate, the products of this reaction will be calcium carbide and carbon monoxide.
Application
This carbonate is the chalk that we regularly see in schools and other elementary and higher educational institutions. They also whitewash ceilings, paint tree trunks in the spring and alkalize the soil in the horticulture industry.
2. Calcium bicarbonate
It is a s alt of carbonic acid. Has the formula Ca(HCO3)2.
Properties
Dissolves in water, like all hydrocarbons. However, he makes her tough for a while. In living organisms, calcium bicarbonate and some other s alts with the same residue have the function of regulators of the constancy of reactions in the blood.
Receive
It is produced by the interaction of carbon dioxide, calcium carbonate and water.
Application
It is found in drinking water, where its concentration can vary from 30 to 400 mg/L.
3. Calcium hydroxide
Formula - Ca(OH)2. This substance is a strong base. In various sources, it may be called slaked lime or "fluff".
Receive
Produced when calcium oxide and water interact.
Properties
It has the appearance of a white powder, slightly soluble in water. With an increase in the temperature of the latter, the numerical value of the solubility decreases. It also has the ability to neutralize acids, during this reaction the corresponding calcium s alts and water are formed. If you add carbon dioxide dissolved in water to it, you getall the same water, and also calcium carbonate. With continued bubbling of CO2, calcium bicarbonate will form.
Application
They whitewash the premises, wooden fences, and also coat the rafters. With the help of this hydroxide, lime mortar, bleach, special fertilizers and silicate concrete are prepared, and they also eliminate the carbonate hardness of water (soften the latter). By means of this substance, potassium and sodium carbonates are causticized, root canals of teeth are disinfected, skins are tanned, and certain plant diseases are cured. Calcium hydroxide is also known as food additive E526.
Conclusion
Now you understand why in this article I decided to describe these three substances? After all, these compounds "meet" with each other during the decomposition and production of each of them. There are many other related substances, but we will talk about them another time.
