Introduction
Every day we breathe in the air we need. Have you ever thought about what, more precisely, of what substances air consists of? Most of it contains nitrogen (78%), followed by oxygen (21%) and inert gases (1%). Although oxygen does not constitute the most basic part of air, without it the atmosphere would be unsuitable for life. Thanks to him, life exists on Earth, because nitrogen and inert gases, together and individually, are harmful to humans. Let's look at the properties of oxygen.
Physical properties of oxygen
In air, oxygen simply cannot be distinguished, since under ordinary conditions it is a gas without taste, color, or smell. But oxygen can be artificially transferred to other states of aggregation. So, at -183 ° C it becomes liquid, and at -219 ° C it hardens. But solid and liquid oxygen can only be obtained by man, and in nature it exists only in a gaseous state. Liquid oxygen looks like this (photo). A solid is like ice.
The physical properties of oxygen is also the structure of a molecule of a simple substance. Oxygen atoms form two such substances: oxygen (O 2 ) and ozone (O 3 ). The following is a model of an oxygen molecule.
Oxygen. Chemical properties
The first thing that begins with the chemical characterization of an element is its position in the periodic system of D. I. Mendeleev. So, oxygen is in the 2nd period of the 6th group of the main subgroup at number 8. Its atomic mass is 16 amu, it is non-metal.
In inorganic chemistry, its binary compounds with other elements were combined into a separate class of inorganic compounds - oxides. Oxygen can form chemical compounds with both metals and non-metals.
Talk about getting it in the labs.
Chemically, oxygen can be obtained by electrolysis of water, decomposition of potassium permanganate, hydrogen peroxide, bertholate salt, nitrates of active metals and oxides of heavy metals. Consider the reaction equations when using each of these methods.
1. Water electrolysis:
2 2 = 2 2 + 2
2. The decomposition of potassium permanganate (potassium permanganate) using a catalyst:
KMnO 4 = K 2 MnO 4 + KMnO 2 + O 2
3. Decomposition of Berthollet salt:
2KClO 3 = 2KCl + 3O 2
4. The decomposition of hydrogen peroxide (hydrogen peroxide) :
H 2 O 2 = H 2 O + O 2
5. Decomposition of heavy metal oxides (for example, mercury oxide):
2HgO = 2Hg + O 2
6. Decomposition of nitrates of active metals (for example, sodium nitrate):
2NaNO 3 = 2NaNO 2 + O 2
Oxygen application
With the chemical properties we are done. Now it's time to talk about the use of oxygen in human life. It is needed for burning fuel in electric and thermal stations. It is used to produce steel from cast iron and scrap metal, for welding and cutting metal. Oxygen is needed for firefighters masks, for cylinders of divers, it is used in ferrous and non-ferrous metallurgy and even in the manufacture of explosives. Also in the food industry, oxygen is known as the E948 food supplement. It seems that there is no industry wherever it is used, but it plays the most important role in medicine. There it is called - "medical oxygen." In order for oxygen to be suitable for use, it is pre-compressed. The physical properties of oxygen help to compress it. In this form, it is stored inside cylinders similar to such.
It is used in resuscitation and operations in equipment to maintain life processes in the patient’s body, as well as in the treatment of certain diseases: decompression, pathologies of the gastrointestinal tract. With it, doctors save many lives every day. The chemical and physical properties of oxygen make it so widely used.