The hydrogen atom has the electronic formula of the outer (and only) electron level 1 s 1 . On the one hand, in terms of the presence of one electron on the outer electronic level, the hydrogen atom is similar to alkali metal atoms. However, just like halogens, it only needs one electron to fill the outer electronic level, since the first electronic level can contain no more than 2 electrons. It turns out that hydrogen can be placed simultaneously in both the first and the penultimate (seventh) group of the periodic table, which is sometimes done in various versions of the periodic system:
From the point of view of the properties of hydrogen as a simple substance, it still has more in common with halogens. Hydrogen, like halogens, is a non-metal and forms diatomic molecules (H 2) like them.
Under normal conditions, hydrogen is a gaseous, low-active substance. The low activity of hydrogen is explained by the high strength of the bonds between the hydrogen atoms in the molecule, the breaking of which requires either strong heating, or the use of catalysts, or both.
Interaction of hydrogen with simple substances
with metals
Of the metals, hydrogen reacts only with alkali and alkaline earth metals! Alkali metals include metals of the main subgroup of group I (Li, Na, K, Rb, Cs, Fr), and alkaline earth metals include metals of the main subgroup of group II, except beryllium and magnesium (Ca, Sr, Ba, Ra)
When interacting with active metals, hydrogen exhibits oxidizing properties, i.e. lowers its oxidation state. In this case, hydrides of alkali and alkaline earth metals are formed, which have an ionic structure. The reaction occurs when heated:
It should be noted that interaction with active metals is the only case when molecular hydrogen H2 is an oxidizing agent.
with non-metals
Of the non-metals, hydrogen reacts only with carbon, nitrogen, oxygen, sulfur, selenium and halogens!
Carbon should be understood as graphite or amorphous carbon, since diamond is an extremely inert allotropic modification of carbon.
When interacting with non-metals, hydrogen can only perform the function of a reducing agent, that is, only increase its oxidation state:
Interaction of hydrogen with complex substances
with metal oxides
Hydrogen does not react with metal oxides that are in the activity series of metals up to aluminum (inclusive), however, it is capable of reducing many metal oxides to the right of aluminum when heated:
with non-metal oxides
Of the non-metal oxides, hydrogen reacts when heated with the oxides of nitrogen, halogens and carbon. Of all the interactions of hydrogen with non-metal oxides, especially noteworthy is its reaction with carbon monoxide CO.
The mixture of CO and H2 even has its own name - “synthesis gas”, since, depending on the conditions, such popular industrial products as methanol, formaldehyde and even synthetic hydrocarbons can be obtained from it:
with acids
Hydrogen does not react with inorganic acids!
Of organic acids, hydrogen reacts only with unsaturated acids, as well as with acids containing functional groups capable of reduction with hydrogen, in particular aldehyde, keto or nitro groups.
with salts
In the case of aqueous solutions of salts, their interaction with hydrogen does not occur. However, when hydrogen is passed over solid salts of some metals of medium and low activity, their partial or complete reduction is possible, for example:
Chemical properties of halogens
Halogens are the chemical elements of group VIIA (F, Cl, Br, I, At), as well as the simple substances they form. Here and further in the text, unless otherwise stated, halogens will be understood as simple substances.
All halogens have a molecular structure, which determines the low melting and boiling points of these substances. Halogen molecules are diatomic, i.e. their formula can be written in general form as Hal 2.
It should be noted such a specific physical property of iodine as its ability to sublimation or, in other words, sublimation. Sublimation, is a phenomenon in which a substance in a solid state does not melt when heated, but, bypassing the liquid phase, immediately passes into the gaseous state.
The electronic structure of the external energy level of an atom of any halogen has the form ns 2 np 5, where n is the number of the periodic table period in which the halogen is located. As you can see, the halogen atoms only need one electron to reach the eight-electron outer shell. From this it is logical to assume the predominantly oxidizing properties of free halogens, which is confirmed in practice. As is known, the electronegativity of nonmetals decreases when moving down a subgroup, and therefore the activity of halogens decreases in the series:
F 2 > Cl 2 > Br 2 > I 2
Interaction of halogens with simple substances
All halogens are highly reactive substances and react with most simple substances. However, it should be noted that fluorine, due to its extremely high reactivity, can react even with those simple substances with which other halogens cannot react. Such simple substances include oxygen, carbon (diamond), nitrogen, platinum, gold and some noble gases (xenon and krypton). Those. actually, fluorine does not react only with some noble gases.
The remaining halogens, i.e. chlorine, bromine and iodine are also active substances, but less active than fluorine. They react with almost all simple substances except oxygen, nitrogen, carbon in the form of diamond, platinum, gold and noble gases.
Interaction of halogens with non-metals
hydrogen
When all halogens interact with hydrogen, they form hydrogen halides with the general formula HHal. In this case, the reaction of fluorine with hydrogen begins spontaneously even in the dark and proceeds with an explosion in accordance with the equation:
The reaction of chlorine with hydrogen can be initiated by intense ultraviolet irradiation or heat. Also proceeds with explosion:
Bromine and iodine react with hydrogen only when heated, and at the same time, the reaction with iodine is reversible:
phosphorus
The interaction of fluorine with phosphorus leads to the oxidation of phosphorus to the highest oxidation state (+5). In this case, phosphorus pentafluoride is formed:
When chlorine and bromine interact with phosphorus, it is possible to obtain phosphorus halides both in the oxidation state + 3 and in the oxidation state +5, which depends on the proportions of the reacting substances:
Moreover, in the case of white phosphorus in an atmosphere of fluorine, chlorine or liquid bromine, the reaction begins spontaneously.
The interaction of phosphorus with iodine can lead to the formation of only phosphorus triodide due to its significantly lower oxidizing ability than that of other halogens:
gray
Fluorine oxidizes sulfur to the highest oxidation state +6, forming sulfur hexafluoride:
Chlorine and bromine react with sulfur, forming compounds containing sulfur in the oxidation states +1 and +2, which are extremely unusual for it. These interactions are very specific, and to pass the Unified State Exam in chemistry, the ability to write equations for these interactions is not necessary. Therefore, the following three equations are given rather for reference:
Interaction of halogens with metals
As mentioned above, fluorine is capable of reacting with all metals, even such inactive ones as platinum and gold:
The remaining halogens react with all metals except platinum and gold:
Reactions of halogens with complex substances
Substitution reactions with halogens
More active halogens, i.e. the chemical elements of which are located higher in the periodic table are capable of displacing less active halogens from the hydrohalic acids and metal halides they form:
Similarly, bromine displaces sulfur from solutions of sulfides and hydrogen sulfide:
Chlorine is a stronger oxidizing agent and oxidizes hydrogen sulfide in its aqueous solution not to sulfur, but to sulfuric acid:
Reaction of halogens with water
Water burns in fluorine with a blue flame in accordance with the reaction equation:
Bromine and chlorine react differently with water than fluorine. If fluorine acted as an oxidizing agent, then chlorine and bromine are disproportionate in water, forming a mixture of acids. In this case, the reactions are reversible:
The interaction of iodine with water occurs to such an insignificant degree that it can be neglected and it can be assumed that the reaction does not occur at all.
Interaction of halogens with alkali solutions
Fluorine, when interacting with an aqueous alkali solution, again acts as an oxidizing agent:
The ability to write this equation is not required to pass the Unified State Exam. It is enough to know the fact about the possibility of such an interaction and the oxidative role of fluorine in this reaction.
Unlike fluorine, other halogens in alkali solutions are disproportionate, that is, they simultaneously increase and decrease their oxidation state. Moreover, in the case of chlorine and bromine, depending on the temperature, flow in two different directions is possible. In particular, in the cold the reactions proceed as follows:
and when heated:
Iodine reacts with alkalis exclusively according to the second option, i.e. with the formation of iodate, because hypoiodite is not stable not only when heated, but also at ordinary temperatures and even in the cold.
Hydrogen is a gas; it is in first place in the Periodic Table. The name of this element, widespread in nature, is translated from Latin as “generating water.” So what physical and chemical properties of hydrogen do we know?
Hydrogen: general information
Under normal conditions, hydrogen has no taste, no smell, no color.
Rice. 1. Formula of hydrogen.
Since an atom has one electronic energy level, which can contain a maximum of two electrons, then for a stable state the atom can either accept one electron (oxidation state -1) or give up one electron (oxidation state +1), exhibiting a constant valence I This is why the symbol of the element hydrogen is placed not only in group IA (the main subgroup of group I) together with the alkali metals, but also in group VIIA (the main subgroup of group VII) together with the halogens. Halogen atoms also lack one electron to fill the outer level, and they, like hydrogen, are nonmetals. Hydrogen exhibits a positive oxidation state in compounds where it is associated with more electronegative nonmetal elements, and a negative oxidation state in compounds with metals.
Rice. 2. The location of hydrogen in the periodic table.
Hydrogen has three isotopes, each of which has its own name: protium, deuterium, tritium. The amount of the latter on Earth is negligible.
Chemical properties of hydrogen
In the simple substance H2, the bond between the atoms is strong (bond energy 436 kJ/mol), therefore the activity of molecular hydrogen is low. Under normal conditions, it reacts only with very reactive metals, and the only non-metal with which hydrogen reacts is fluorine:
F 2 +H 2 =2HF (hydrogen fluoride)
Hydrogen reacts with other simple (metals and non-metals) and complex (oxides, unspecified organic compounds) substances either upon irradiation and increased temperature, or in the presence of a catalyst.
Hydrogen burns in oxygen, releasing a significant amount of heat:
2H 2 +O 2 =2H 2 O
A mixture of hydrogen and oxygen (2 volumes of hydrogen and 1 volume of oxygen) explodes violently when ignited and is therefore called detonating gas. When working with hydrogen, safety regulations must be followed.
Rice. 3. Explosive gas.
In the presence of catalysts, the gas can react with nitrogen:
3H 2 +N 2 =2NH 3
– this reaction at elevated temperatures and pressures produces ammonia in industry.
At high temperatures, hydrogen is able to react with sulfur, selenium, and tellurium. and when interacting with alkali and alkaline earth metals, the formation of hydrides occurs: 4.3. Total ratings received: 186.
Hydrogen (H) is a very light chemical element, with a content of 0.9% by weight in the Earth's crust and 11.19% in water.
Characteristics of hydrogen
It is the first among gases in lightness. Under normal conditions, it is tasteless, colorless, and absolutely odorless. When it enters the thermosphere, it flies off into space due to its low weight.
In the entire universe, it is the most numerous chemical element (75% of the total mass of substances). So much so that many stars in outer space are made entirely of it. For example, the Sun. Its main component is hydrogen. And heat and light are the result of the release of energy when the nuclei of a material merge. Also in space there are entire clouds of its molecules of various sizes, densities and temperatures.
Physical properties
High temperature and pressure significantly change its qualities, but under normal conditions it:
It has high thermal conductivity when compared with other gases,
Non-toxic and poorly soluble in water,
With a density of 0.0899 g/l at 0°C and 1 atm.,
Turns into liquid at a temperature of -252.8°C
Becomes hard at -259.1°C.,
Specific heat of combustion 120.9.106 J/kg.
It requires high pressure and very low temperatures to turn into a liquid or solid. In a liquefied state, it is fluid and light.
Chemical properties
Under pressure and upon cooling (-252.87 degrees C), hydrogen acquires a liquid state, which is lighter in weight than any analogue. It takes up less space in it than in gaseous form.
It is a typical non-metal. In laboratories, it is produced by reacting metals (such as zinc or iron) with dilute acids. Under normal conditions it is inactive and reacts only with active non-metals. Hydrogen can separate oxygen from oxides, and reduce metals from compounds. It and its mixtures form hydrogen bonds with certain elements.
The gas is highly soluble in ethanol and in many metals, especially palladium. Silver does not dissolve it. Hydrogen can be oxidized during combustion in oxygen or air, and when interacting with halogens.
When it combines with oxygen, water is formed. If the temperature is normal, then the reaction proceeds slowly; if it is above 550°C, it explodes (it turns into detonating gas).
Finding hydrogen in nature
Although there is a lot of hydrogen on our planet, it is not easy to find in its pure form. A little can be found during volcanic eruptions, during oil production and where organic matter decomposes.
More than half of the total amount is in the composition with water. It is also included in the structure of oil, various clays, flammable gases, animals and plants (presence in every living cell is 50% by the number of atoms).
Hydrogen cycle in nature
Every year, a colossal amount (billions of tons) of plant residues decomposes in water bodies and soil, and this decomposition releases a huge mass of hydrogen into the atmosphere. It is also released during any fermentation caused by bacteria, combustion and, along with oxygen, participates in the water cycle.
Hydrogen Applications
The element is actively used by humanity in its activities, so we have learned to obtain it on an industrial scale for:
Meteorology, chemical production;
Margarine production;
As rocket fuel (liquid hydrogen);
Electric power industry for cooling electric generators;
Welding and cutting of metals.
A lot of hydrogen is used in the production of synthetic gasoline (to improve the quality of low-quality fuel), ammonia, hydrogen chloride, alcohols, and other materials. Nuclear energy actively uses its isotopes.
The drug “hydrogen peroxide” is widely used in metallurgy, the electronics industry, pulp and paper production, for bleaching linen and cotton fabrics, for the production of hair dyes and cosmetics, polymers and in medicine for the treatment of wounds.
The "explosive" nature of this gas can become a lethal weapon - a hydrogen bomb. Its explosion is accompanied by the release of a huge amount of radioactive substances and is destructive for all living things.
Contact of liquid hydrogen and skin can cause severe and painful frostbite.
- Designation - H (Hydrogen);
- Latin name - Hydrogenium;
- Period - I;
- Group - 1 (Ia);
- Atomic mass - 1.00794;
- Atomic number - 1;
- Atomic radius = 53 pm;
- Covalent radius = 32 pm;
- Electron distribution - 1s 1;
- melting temperature = -259.14°C;
- boiling point = -252.87°C;
- Electronegativity (according to Pauling/according to Alpred and Rochow) = 2.02/-;
- Oxidation state: +1; 0; -1;
- Density (no.) = 0.0000899 g/cm 3 ;
- Molar volume = 14.1 cm 3 /mol.
Binary compounds of hydrogen with oxygen:
Hydrogen (“giving birth to water”) was discovered by the English scientist G. Cavendish in 1766. It is the simplest element in nature - a hydrogen atom has a nucleus and one electron, which is probably why hydrogen is the most abundant element in the Universe (accounting for more than half the mass of most stars).
About hydrogen we can say that “the spool is small, but expensive.” Despite its “simplicity,” hydrogen provides energy to all living beings on Earth - a continuous thermonuclear reaction takes place on the Sun during which one helium atom is formed from four hydrogen atoms, this process is accompanied by the release of a colossal amount of energy (for more details, see Nuclear fusion).
In the earth's crust, the mass fraction of hydrogen is only 0.15%. Meanwhile, the overwhelming majority (95%) of all chemical substances known on Earth contain one or more hydrogen atoms.
In compounds with non-metals (HCl, H 2 O, CH 4 ...), hydrogen gives up its only electron to more electronegative elements, exhibiting an oxidation state of +1 (more often), forming only covalent bonds (see Covalent bond).
In compounds with metals (NaH, CaH 2 ...), hydrogen, on the contrary, accepts another electron into its only s-orbital, thus trying to complete its electronic layer, exhibiting an oxidation state of -1 (less often), often forming an ionic bond (see Ionic bond), because the difference in electronegativity of the hydrogen atom and the metal atom can be quite large.
H 2
In the gaseous state, hydrogen exists in the form of diatomic molecules, forming a nonpolar covalent bond.
Hydrogen molecules have:
- great mobility;
- great strength;
- low polarizability;
- small size and weight.
Properties of hydrogen gas:
- the lightest gas in nature, colorless and odorless;
- poorly soluble in water and organic solvents;
- dissolves in small amounts in liquid and solid metals (especially platinum and palladium);
- difficult to liquefy (due to its low polarizability);
- has the highest thermal conductivity of all known gases;
- when heated, it reacts with many non-metals, exhibiting the properties of a reducing agent;
- at room temperature it reacts with fluorine (an explosion occurs): H 2 + F 2 = 2HF;
- reacts with metals to form hydrides, exhibiting oxidizing properties: H 2 + Ca = CaH 2 ;
In compounds, hydrogen exhibits its reducing properties much more strongly than its oxidizing properties. Hydrogen is the most powerful reducing agent after coal, aluminum and calcium. The reducing properties of hydrogen are widely used in industry to obtain metals and nonmetals (simple substances) from oxides and gallides.
Fe 2 O 3 + 3H 2 = 2Fe + 3H 2 O
Reactions of hydrogen with simple substances
Hydrogen accepts an electron, playing a role reducing agent, in reactions:
- With oxygen(when ignited or in the presence of a catalyst), in a ratio of 2:1 (hydrogen:oxygen) an explosive detonating gas is formed: 2H 2 0 +O 2 = 2H 2 +1 O+572 kJ
- With gray(when heated to 150°C-300°C): H 2 0 +S ↔ H 2 +1 S
- With chlorine(when ignited or irradiated with UV rays): H 2 0 +Cl 2 = 2H +1 Cl
- With fluorine: H 2 0 +F 2 = 2H +1 F
- With nitrogen(when heated in the presence of catalysts or at high pressure): 3H 2 0 +N 2 ↔ 2NH 3 +1
Hydrogen donates an electron, playing a role oxidizing agent, in reactions with alkaline And alkaline earth metals with the formation of metal hydrides - salt-like ionic compounds containing hydride ions H - these are unstable white crystalline substances.
Ca+H 2 = CaH 2 -1 2Na+H 2 0 = 2NaH -1
It is not typical for hydrogen to exhibit an oxidation state of -1. When reacting with water, the hydrides decompose, reducing water to hydrogen. The reaction of calcium hydride with water is as follows:
CaH 2 -1 +2H 2 +1 0 = 2H 2 0 +Ca(OH) 2
Reactions of hydrogen with complex substances
- at high temperatures, hydrogen reduces many metal oxides: ZnO+H 2 = Zn+H 2 O
- methyl alcohol is obtained by the reaction of hydrogen with carbon monoxide (II): 2H 2 +CO → CH 3 OH
- In hydrogenation reactions, hydrogen reacts with many organic substances.
The equations of chemical reactions of hydrogen and its compounds are discussed in more detail on the page “Hydrogen and its compounds - equations of chemical reactions involving hydrogen.”
Applications of hydrogen
- in nuclear energy, hydrogen isotopes are used - deuterium and tritium;
- in the chemical industry, hydrogen is used for the synthesis of many organic substances, ammonia, hydrogen chloride;
- in the food industry, hydrogen is used in the production of solid fats through the hydrogenation of vegetable oils;
- for welding and cutting metals, the high combustion temperature of hydrogen in oxygen (2600°C) is used;
- in the production of some metals, hydrogen is used as a reducing agent (see above);
- since hydrogen is a light gas, it is used in aeronautics as a filler for balloons, aerostats, and airships;
- Hydrogen is used as a fuel mixed with CO.
Recently, scientists have been paying a lot of attention to the search for alternative sources of renewable energy. One of the promising areas is “hydrogen” energy, in which hydrogen is used as fuel, the combustion product of which is ordinary water.
Methods for producing hydrogen
Industrial methods for producing hydrogen:
- methane conversion (catalytic reduction of water vapor) with water vapor at high temperature (800°C) on a nickel catalyst: CH 4 + 2H 2 O = 4H 2 + CO 2 ;
- conversion of carbon monoxide with water vapor (t=500°C) on a Fe 2 O 3 catalyst: CO + H 2 O = CO 2 + H 2 ;
- thermal decomposition of methane: CH 4 = C + 2H 2;
- gasification of solid fuels (t=1000°C): C + H 2 O = CO + H 2 ;
- electrolysis of water (a very expensive method that produces very pure hydrogen): 2H 2 O → 2H 2 + O 2.
Laboratory methods for producing hydrogen:
- action on metals (usually zinc) with hydrochloric or dilute sulfuric acid: Zn + 2HCl = ZCl 2 + H 2 ; Zn + H 2 SO 4 = ZnSO 4 + H 2;
- interaction of water vapor with hot iron filings: 4H 2 O + 3Fe = Fe 3 O 4 + 4H 2.
It has its own specific position in the periodic table, which reflects the properties it exhibits and speaks about its electronic structure. However, among all of them there is one special atom that occupies two cells at once. It is located in two groups of elements that are completely opposite in their properties. This is hydrogen. Such features make it unique.
Hydrogen is not just an element, but also a simple substance, as well as an integral part of many complex compounds, a biogenic and organogenic element. Therefore, let us consider its characteristics and properties in more detail.
Hydrogen as a chemical element
Hydrogen is an element of the first group of the main subgroup, as well as the seventh group of the main subgroup in the first minor period. This period consists of only two atoms: helium and the element we are considering. Let us describe the main features of the position of hydrogen in the periodic table.
- The atomic number of hydrogen is 1, the number of electrons is the same, and, accordingly, the number of protons is the same. Atomic mass - 1.00795. There are three isotopes of this element with mass numbers 1, 2, 3. However, the properties of each of them are very different, since an increase in mass even by one for hydrogen is immediately double.
- The fact that it contains only one electron on its outer surface allows it to successfully exhibit both oxidizing and reducing properties. In addition, after donating an electron, it remains with a free orbital, which takes part in the formation of chemical bonds according to the donor-acceptor mechanism.
- Hydrogen is a strong reducing agent. Therefore, its main place is considered to be the first group of the main subgroup, where it heads the most active metals - alkali.
- However, when interacting with strong reducing agents, such as metals, it can also be an oxidizing agent, accepting an electron. These compounds are called hydrides. According to this feature, it heads the subgroup of halogens with which it is similar.
- Due to its very small atomic mass, hydrogen is considered the lightest element. In addition, its density is also very low, so it is also a benchmark for lightness.
Thus, it is obvious that the hydrogen atom is a completely unique element, unlike all other elements. Consequently, its properties are also special, and the simple and complex substances formed are very important. Let's consider them further.
Simple substance
If we talk about this element as a molecule, then we must say that it is diatomic. That is, hydrogen (a simple substance) is a gas. Its empirical formula will be written as H2, and its graphical formula will be written through a single sigma H-H relationship. The mechanism of bond formation between atoms is covalent nonpolar.
- Steam methane reforming.
- Coal gasification - the process involves heating coal to 1000 0 C, resulting in the formation of hydrogen and high-carbon coal.
- Electrolysis. This method can only be used for aqueous solutions of various salts, since the melts do not lead to a discharge of water at the cathode.
Laboratory methods for producing hydrogen:
- Hydrolysis of metal hydrides.
- The effect of dilute acids on active metals and medium activity.
- Interaction of alkali and alkaline earth metals with water.
To collect the hydrogen produced, you must hold the test tube upside down. After all, this gas cannot be collected in the same way as, for example, carbon dioxide. This is hydrogen, it is much lighter than air. It evaporates quickly, and in large quantities it explodes when mixed with air. Therefore, the test tube should be inverted. After filling it, it must be closed with a rubber stopper.
To check the purity of the collected hydrogen, you should bring a lit match to the neck. If the clap is dull and quiet, it means the gas is clean, with minimal air impurities. If it is loud and whistling, it is dirty, with a large proportion of foreign components.
Areas of use
When hydrogen is burned, such a large amount of energy (heat) is released that this gas is considered the most profitable fuel. Moreover, it is environmentally friendly. However, to date its application in this area is limited. This is due to ill-conceived and unsolved problems of synthesizing pure hydrogen, which would be suitable for use as fuel in reactors, engines and portable devices, as well as residential heating boilers.
After all, the methods for producing this gas are quite expensive, so first it is necessary to develop a special synthesis method. One that will allow you to obtain the product in large volumes and at minimal cost.
There are several main areas in which the gas we are considering is used.
- Chemical syntheses. Hydrogenation is used to produce soaps, margarines, and plastics. With the participation of hydrogen, methanol and ammonia, as well as other compounds, are synthesized.
- In the food industry - as additive E949.
- Aviation industry (rocket science, aircraft manufacturing).
- Electric power industry.
- Meteorology.
- Environmentally friendly fuel.
Obviously, hydrogen is as important as it is abundant in nature. The various compounds it forms play an even greater role.
Hydrogen compounds
These are complex substances containing hydrogen atoms. There are several main types of such substances.
- Hydrogen halides. The general formula is HHal. Of particular importance among them is hydrogen chloride. It is a gas that dissolves in water to form a solution of hydrochloric acid. This acid is widely used in almost all chemical syntheses. Moreover, both organic and inorganic. Hydrogen chloride is a compound with the empirical formula HCL and is one of the largest produced in our country annually. Hydrogen halides also include hydrogen iodide, hydrogen fluoride and hydrogen bromide. They all form the corresponding acids.
- Volatile Almost all of them are quite poisonous gases. For example, hydrogen sulfide, methane, silane, phosphine and others. At the same time, they are very flammable.
- Hydrides are compounds with metals. They belong to the class of salts.
- Hydroxides: bases, acids and amphoteric compounds. They necessarily contain hydrogen atoms, one or more. Example: NaOH, K 2, H 2 SO 4 and others.
- Hydrogen hydroxide. This compound is better known as water. Another name is hydrogen oxide. The empirical formula looks like this - H 2 O.
- Hydrogen peroxide. This is a strong oxidizing agent, the formula of which is H 2 O 2.
- Numerous organic compounds: hydrocarbons, proteins, fats, lipids, vitamins, hormones, essential oils and others.
It is obvious that the variety of compounds of the element we are considering is very large. This once again confirms its high importance for nature and humans, as well as for all living beings.
- this is the best solvent
As mentioned above, the common name for this substance is water. Consists of two hydrogen atoms and one oxygen, connected by covalent polar bonds. The water molecule is a dipole, this explains many of the properties it exhibits. In particular, it is a universal solvent.
It is in the aquatic environment that almost all chemical processes occur. Internal reactions of plastic and energy metabolism in living organisms are also carried out using hydrogen oxide.
Water is rightfully considered the most important substance on the planet. It is known that no living organism can live without it. On Earth it can exist in three states of aggregation:
- liquid;
- gas (steam);
- solid (ice).
Depending on the isotope of hydrogen included in the molecule, three types of water are distinguished.
- Light or protium. An isotope with mass number 1. Formula - H 2 O. This is the usual form that all organisms use.
- Deuterium or heavy, its formula is D 2 O. Contains the isotope 2 H.
- Super heavy or tritium. The formula looks like T 3 O, isotope - 3 H.
The reserves of fresh protium water on the planet are very important. There is already a shortage of it in many countries. Methods are being developed for treating salt water to produce drinking water.
Hydrogen peroxide is a universal remedy
This compound, as mentioned above, is an excellent oxidizing agent. However, with strong representatives he can also behave as a restorer. In addition, it has a pronounced bactericidal effect.
Another name for this compound is peroxide. It is in this form that it is used in medicine. A 3% solution of crystalline hydrate of the compound in question is a medical medicine that is used to treat small wounds for the purpose of disinfecting them. However, it has been proven that this increases the healing time of the wound.
Hydrogen peroxide is also used in rocket fuel, in industry for disinfection and bleaching, and as a foaming agent for the production of appropriate materials (foam, for example). Additionally, peroxide helps clean aquariums, bleach hair, and whiten teeth. However, it causes harm to tissues, so it is not recommended by specialists for these purposes.