The most important and widespread substance on our planet is, of course, water. What can be compared with it in importance? It is known that life on Earth became possible only with the advent of liquid. What is water (hydrogen oxide) from a chemical point of view? What does it consist of and what properties does it have? Let's try to understand this article.
Hydrogen and its compounds
The lightest atom in the entire periodic table is hydrogen. It also occupies a dual position, being located both in the subgroup of halogens and in the first group of alkali metals. What explains such features? The electronic structure of the shell of its atom. It has only one electron, which is free to both leave and attach another one to itself, forming a pair and completing the outer level.
That is why the main and only oxidation states of this element are +1 and -1. It easily reacts with metals, forming hydrides - solid non-volatile s alt-like compounds of white color.
However, hydrogen also easily forms volatile molecules of substances, interacting with non-metals. For example:
- hydrogen sulfide H2S;
- methaneCH4;
- silane SiH4 and others.
In general, hydrogen forms quite a lot of compounds. However, the most important substance in which it is included is hydrogen oxide, the formula of which is H2O. This is the most famous compound that even a primary school student who is not yet familiar with chemistry recognizes by the formula. After all, water (and this is the highest hydrogen oxide) is not only a common substance, but also a source of life on our planet.
The very name of the element reflects its main essence - hydrogen, that is, "giving birth to water". Like any other oxide, this one is also a binary compound with a number of physical and chemical properties. In addition, there are special characteristics that distinguish water from all other compounds.
Also an important class of compounds that form hydrogen are acids, both organic and mineral.
Chemical properties of hydrogen
From the point of view of chemical activity, hydrogen is a fairly strong reducing agent. In many reactions, it exhibits just such properties. However, when interacting with even stronger metals, it becomes an oxidizing agent.
Very important in industry is the interaction of hydrogen with metal oxides. After all, this is one of the ways to get the latter in its purest form. Hydrogen thermal is a metallurgical method for the synthesis of pure metals from their oxides by reduction with hydrogen.
The reaction of hydrogen with oxide has the following general form:MexOy + H2=H2O + Me.
Of course, this is not the only way to synthesize pure metals. There are others. However, the reduction of oxides with hydrogen is an energetically quite profitable and uncomplicated production process that has found wide application.
Also interesting is the fact that when mixed with air, hydrogen gas can form a highly explosive mixture. Its name is explosive gas. To do this, mixing should be done at the rate of two volumes of hydrogen per one oxygen.
Water is hydrogen oxide
The fact that this oxide is very important, we have already mentioned several times. Now let's characterize it in terms of chemistry. Does this compound really belong to this class of inorganic substances?
To do this, he will try to write the formula a little differently: H2O=HON. The essence is the same, the number of atoms is the same, however, now it is obvious that we have hydroxide in front of us. What properties should it have? Consider the dissociation of the compound:
NON=H+ + OH-.
Consequently, the properties are acidic, since hydrogen cations are present in the solution. In addition, they cannot be basic, because alkalis form only metals.
Therefore, another name that has hydrogen oxide is an oxygen-containing acid of the simplest composition. Since such complex interlacings are characteristic of a given molecule, therefore, its properties will be special. And the properties are repelled fromthe structure of the molecule, so we will analyze it.
The structure of the water molecule
For the first time, Niels Bohr thought about this model, and he owns the primacy and authorship in this matter. They installed the following traits.
- The water molecule is a dipole, since the elements that make up it differ greatly in electronegativity.
- Its triangular shape, hydrogens at the base and oxygen at the top.
- Due to this structure, this substance is able to form hydrogen bonds, both between molecules of the same name, and with other compounds that have a strongly electronegative element in their composition.
See how the hydrogen oxide in question looks schematically in the photo below.
Physical properties of hydrogen oxide
Several main characteristics can be identified.
- State of aggregation: gaseous - steam, liquid, solid - snow, ice.
- Boiling point - 1000C (99, 974).
- Melting point - 00C.
- Water is able to shrink when heated in the temperature range from 0-40C. This explains the formation of ice on the surface, which has a lower density and the preservation of life under the thickness of hydrogen oxide.
- High heat capacity but very low thermal conductivity.
- In the liquid state, hydrogen oxide exhibits viscosity.
- Surface tension and the formation of negativeelectric potential on the water surface.
As we noted above, the features of the properties depend on the structure. So here. The ability to form hydrogen bonds has led to similar traits in this compound.
Hydrogen oxide: chemical properties
From the point of view of chemistry, the activity of water is quite high. Especially when it comes to reactions accompanied by heating. What can hydrogen oxide react with?
- With metals, which in a series of voltages are up to hydrogen. At the same time, special conditions are not needed with the most active (up to aluminum), and those with a lower reducing ability react only with steam. Those that stand after hydrogen are not capable of entering into such interactions at all.
- With nonmetals. Not with everyone, but with the majority. For example, in an atmosphere of fluorine, water burns with a violet flame. Also reaction is possible with chlorine, carbon, silicon and other atoms.
- With metal oxides (basic) and acidic (non-metals). Alkalis and acids are formed, respectively. Among metals, representatives of the first two groups of the main subgroups are capable of such reactions, except for magnesium and beryllium. Non-metals that form acidic oxides interact with water all. The exception is river sand - SiO2.
The reaction equation for hydrogen oxide is as an example: SO3 + H2O=H2 SO4.
Spread in nature
We have already found out that this substance -the most widespread in the world. Let's denote the percentage in objects.
- About 70% of the body weight of humans and mammals. Some fauna are about 98% hydrogen oxide (jellyfish).
- 71% of the Earth is covered with water.
- The largest mass is the water of the oceans.
- About 2% is found in glaciers.
- 0, 63% underground.
- 0.001% is atmospheric (fog).
- The body of plants is 50% water, some species even more.
- Many compounds occur as crystalline hydrates containing bound water.
This list can be continued for a long time, because it is difficult to remember anything that does not include water or once did not. Or formed without the participation of this oxide.
Methods of obtaining
Obtaining hydrogen oxide has no industrial value. After all, it is easier to use ready-made sources - rivers, lakes and other bodies of water than to spend a huge amount of energy and reagents. Therefore, in the laboratory, it is only appropriate to obtain distilled, highly pure water.
For these purposes, certain devices are used, such as distillation cubes. Such water is necessary for carrying out many chemical interactions, since untreated water contains a large amount of impurities, s alts, ions.
Biological role
To say that water is used everywhere is an understatement. It is unthinkable to imagine your life without this connection. From themorning and until nightfall, a person constantly uses it for both domestic and industrial purposes.
Hydrogen oxide properties imply its use as a universal solvent. And not only in the laboratory. But also in living beings, where thousands of biochemical reactions take place every second.
Also, water itself is a participant in many syntheses, it also serves as a by-product resulting from them. Every person on Earth passes through about 50 tons of this amazing substance in 60 years!
Hydrogen oxide used:
- in all industries;
- medicine;
- chemical syntheses;
- in all types of industries;
- household needs;
- agriculture.
It is difficult to define an area of life in which you can do without water. The only living beings that do not have hydrogen oxide in their composition and live without it are viruses. That is why it is difficult for a person to fight these organisms.
