Physical properties of oxygen

Introduction

Every day we breathe in the air we need. Have you ever thought about what, more precisely from what substances, does the air consist? The most nitrogen in it (78%), followed by oxygen (21%) and inert gases (1%). Although oxygen does not constitute the most basic part of the air, but without it, the atmosphere would be unsuitable for life. Thanks to him, there is life on Earth, because nitrogen and inert gases together and separately are harmful to humans. Let's look at the properties of oxygen.

Physical properties of oxygen

In the air, oxygen is simply not distinguishable, since under normal conditions it is a gas without taste, color and odor. But oxygen can be artificially converted to other aggregate states. Thus, at -183 ° C it becomes liquid, and at -219 ° C hardens. But solid and liquid oxygen can be obtained only by man, but in nature it exists only in the gaseous state. Liquid oxygen looks like this (photo). And the solid is like ice.

The physical properties of oxygen are also the structure of the molecule of a simple substance. Atoms of oxygen form two such substances: oxygen (O ₂ ) and ozone (O ₃ ). Below is a model of an oxygen molecule.

Oxygen. Chemical properties

The first, with which the chemical characteristic of the element begins, is its position in the periodical system of DI Mendeleyev. So, oxygen is in the 2nd period of the 6th group to the main subgroup at number 8. Its atomic mass is 16 amu, it is a nonmetal.

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.

Let's talk about getting it in laboratories.

By chemical means, oxygen can be obtained by electrolysis of water, decomposition of potassium permanganate, hydrogen peroxide, bertholets salt, active metal nitrates and heavy metal oxides. Consider the reaction equations for each of these methods.

1. Electrolysis of water:

2H ₂ O = 2H ₂ + O ₂

2. Decomposition of potassium permanganate (manganese) with a catalyst:

KMnO ₄ = K ₂ MnO ₄ + KMnO ₂ + O ₂

3. Decomposition of the Bertoleth salt:

2KClO ₃ = 2KCl + 3 O ₂

4. 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 + O2

6. Decomposition of active metal nitrates (eg sodium nitrate):

2NaNO ₃ = 2NaNO ₂ + O ₂

Application of oxygen

We have finished chemical properties. 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 iron and scrap, for welding and cutting metal. Oxygen is needed for firemen's masks, for divers cylinders, used in ferrous and non-ferrous metallurgy and even in the manufacture of explosives. Also in the food industry, oxygen is known as food additive E948. It seems that there is no industry where it is not used, but it plays the most important role in medicine. There he is called - "oxygen medical". In order for oxygen to be suitable for use, it is pre-compressed. The physical properties of oxygen contribute to the fact that it can be compressed. In this form it is stored inside cylinders similar to these.

It is used in resuscitation and operations in the equipment to maintain life processes in the patient's body, as well as in the treatment of certain diseases: decompression, gastrointestinal pathologies. With his help, doctors save many lives every day. The chemical and physical properties of oxygen contribute to the fact that it is used so widely.