Characterization of s-elements

The block of s-elements includes 13 elements, common to which is the building up in their atoms of the s-sublevel of the external energy level.

Although hydrogen and helium are classified as s-elements due to the specific nature of their properties, they should be considered separately. Hydrogen, sodium, potassium, magnesium, calcium are vital elements.

Compounds of s-elements show common patterns in properties, which is explained by the similarity electronic structure their atoms. All external electrons are valence and take part in the formation of chemical bonds. Therefore, the maximum oxidation state of these elements in compounds is number electrons in the outer layer and, accordingly, is equal to the number of the group in which this element is located. The oxidation state of s-element metals is always positive. Another feature is that after the separation of the electrons of the outer layer, an ion with a noble gas shell remains. With an increase in the serial number of the element, atomic radius, the ionization energy decreases (from 5.39 eV y Li to 3.83 eV y Fr), and the reducing activity of the elements increases.

The vast majority of compounds of s-elements are colorless (unlike compounds of d-elements), since the transition of d-electrons from low energy levels to higher energy levels, which causes color, is excluded.

Compounds of elements of groups IA - IIA are typical salts; in an aqueous solution, they almost completely dissociate into ions and are not subject to cation hydrolysis (except for Be 2+ and Mg 2+ salts).

hydrogen hydride ionic covalent

For ions of s-elements, complex formation is not typical. Crystalline complexes of s - elements with ligands H 2 O-crystalline hydrates have been known since ancient times, for example: Na 2 B 4 O 7 10H 2 O-borax, KАl (SO 4) 2 12H 2 O-alum. Water molecules in crystalline hydrates are grouped around the cation, but sometimes completely surround the anion. Due to the small charge of the ion and the large radius of the ion, alkali metals are least prone to the formation of complexes, including aqua complexes. as complexing agents in complex compounds ions of lithium, beryllium, magnesium act as low stability.

Hydrogen. Chemical properties of hydrogen

Hydrogen is the lightest s-element. Its electronic configuration in the ground state is 1S 1 . A hydrogen atom consists of one proton and one electron. The peculiarity of hydrogen is that its valence electron is directly in the sphere of action atomic nucleus. Hydrogen does not have an intermediate electron layer, so hydrogen cannot be considered an electronic analogue of alkali metals.

Like alkali metals, hydrogen is a reducing agent and exhibits an oxidation state of +1. The spectra of hydrogen are similar to those of alkali metals. So alkali metals hydrogen is brought closer by its ability to give a hydrated positively charged ion H + in solutions.

Like the halogen, the hydrogen atom is missing one electron. This is the reason for the existence of the hydride ion H - .

In addition, like halogen atoms, hydrogen atoms are characterized by a high ionization energy (1312 kJ/mol). Thus, hydrogen occupies a special position in the Periodic Table of the Elements.

Hydrogen is the most abundant element in the universe, accounting for up to half the mass of the sun and most stars.

On the sun and other planets, hydrogen is in the atomic state, in the interstellar medium in the form of partially ionized diatomic molecules.

Hydrogen has three isotopes; protium 1 H, deuterium 2 D and tritium 3 T, with tritium being a radioactive isotope.

Hydrogen molecules are distinguished by high strength and low polarizability, small size and low mass, and have high mobility. Therefore, hydrogen has very low melting points (-259.2 o C) and boiling points (-252.8 o C). Because of high energy dissociation (436 kJ / mol) the decomposition of molecules into atoms occurs at temperatures above 2000 ° C. Hydrogen is a colorless gas, odorless and tasteless. It has a low density - 8.99·10 -5 g/cm At very high pressures, hydrogen passes into the metallic state. It is believed that on distant planets solar system- Jupiter and Saturn, hydrogen is in a metallic state. There is an assumption that the composition of the earth's core also includes metallic hydrogen, where it is at the superhigh pressure created by the earth's mantle.

Chemical properties. At room temperature, molecular hydrogen reacts only with fluorine, when irradiated with light - with chlorine and bromine, when heated with O 2, S, Se, N 2, C, I 2.

The reactions of hydrogen with oxygen and halogens proceed according to the radical mechanism.

Interaction with chlorine is an example of an unbranched reaction when irradiated with light (photochemical activation), when heated (thermal activation).

Cl + H 2 \u003d HCl + H (chain development)

H + Cl 2 \u003d HCl + Cl

An explosion of explosive gas - a hydrogen-oxygen mixture - is an example of a branched chain process, when the initiated chain includes not one, but several stages:

H 2 + O 2 \u003d 2OH

H + O 2 \u003d OH + O

O + H 2 \u003d OH + H

OH + H 2 \u003d H 2 O + H

The explosive process can be avoided by working with pure hydrogen.

Since hydrogen is characterized by positive (+1) and negative (-1) oxidation states, hydrogen can exhibit both reducing and oxidizing properties.

Restorative properties hydrogen are manifested when interacting with non-metals:

H 2 (g) + Cl 2 (g) \u003d 2HCl (g),

2H 2 (g) + O 2 (g) \u003d 2H 2 O (g),

These reactions proceed with the release of a large amount of heat, which indicates a high energy (strength) of the H-Cl, H-O bonds. Therefore, hydrogen exhibits reducing properties with respect to many oxides, halides, for example:

This is the basis for the use of hydrogen as a reducing agent for obtaining simple substances from halide oxides.

An even stronger reducing agent is atomic hydrogen. It is formed from molecular in an electron discharge under low pressure conditions.

Hydrogen has a high reducing activity at the moment of release during the interaction of a metal with an acid. Such hydrogen reduces CrCl 3 to CrCl 2:

2CrCl 3 + 2HCl + 2Zn = 2CrCl 2 + 2ZnCl 2 + H 2 ^

The interaction of hydrogen with nitric oxide (II) is important:

2NO + 2H 2 = N 2 + H 2 O

Used in purification systems in the production of nitric acid.

As an oxidizing agent, hydrogen interacts with active metals:

In this case, hydrogen behaves like a halogen, forming similar halides hydrides.

Hydrides of group I s-elements have an ionic structure of the NaCl type. Chemically, ionic hydrides behave like basic compounds.

The covalent ones include hydrides of non-metallic elements less electronegative than hydrogen itself, for example, hydrides of the composition SiH 4, BH 3, CH 4. By chemical nature Non-metal hydrides are acidic compounds.

A characteristic feature of the hydrolysis of hydrides is the release of hydrogen, the reaction proceeds according to the redox mechanism.

Basic hydride

acid hydride

Due to the release of hydrogen, the hydrolysis proceeds completely and irreversibly (?Н<0, ?S>0). In this case, basic hydrides form an alkali, and acidic acids.

The standard potential of the system is B. Therefore, the H ion is a strong reducing agent.

In the laboratory, hydrogen is obtained by reacting zinc with 20% sulfuric acid in a Kipp apparatus.

Technical zinc often contains small impurities of arsenic and antimony, which are reduced by hydrogen at the time of release to toxic gases: arsine SbH 3 and stabyne SbH Such hydrogen can be poisonous. With chemically pure zinc, the reaction proceeds slowly due to overvoltage and a good hydrogen current cannot be obtained. The rate of this reaction is increased by adding crystals of copper sulphate, the reaction is accelerated by the formation of a galvanic Cu-Zn pair.

More pure hydrogen is formed by the action of alkali on silicon or aluminum when heated:

In industry, pure hydrogen is obtained by electrolysis of water containing electrolytes (Na 2 SO 4 , Ba (OH) 2).

A large amount of hydrogen is formed as a by-product during electrolysis aqueous solution sodium chloride with a diaphragm separating the cathode and anode space,

The largest amount of hydrogen is obtained by gasification of solid fuel (anthracite) with superheated steam:

Or conversion of natural gas (methane) by superheated steam:

The resulting mixture (synthesis gas) is used in the production of many organic compounds. The yield of hydrogen can be increased by passing synthesis gas over the catalyst, while CO is converted to CO 2 .

Application. A large amount of hydrogen is consumed in the synthesis of ammonia. for the production of hydrogen chloride and of hydrochloric acid, for the hydrogenation of vegetable fats, for the recovery of metals (Mo, W, Fe) from oxides. Hydrogen-oxygen flames are used for welding, cutting and melting metals.

Liquid hydrogen is used as rocket fuel. Hydrogen fuel is environmentally friendly and more energy-intensive than gasoline, so it may replace petroleum products in the future. Already, several hundred cars are running on hydrogen in the world. The problems of hydrogen energy are associated with the storage and transportation of hydrogen. Hydrogen is stored in underground tankers in a liquid state under a pressure of 100 atm. Shipping large quantities liquid hydrogen poses a serious danger.

Let's take a look at what hydrogen is. The chemical properties and production of this non-metal are studied in the course of inorganic chemistry at school. It is this element that leads periodic system Mendeleev, and therefore deserves a detailed description.

Brief information about opening an element

Before considering the physical and chemical properties of hydrogen, let's find out how this important element was found.

Chemists who worked in the sixteenth and seventeenth centuries repeatedly mentioned in their writings the combustible gas that is released when acids are exposed to active metals. In the second half of the eighteenth century, G. Cavendish managed to collect and analyze this gas, giving it the name "combustible gas".

The physical and chemical properties of hydrogen at that time were not studied. Only at the end of the eighteenth century, A. Lavoisier managed to establish by analysis that this gas can be obtained by analyzing water. A little later, he began to call the new element hydrogene, which means "giving birth to water." Hydrogen owes its modern Russian name to M.F. Solovyov.

Being in nature

The chemical properties of hydrogen can only be analyzed based on its abundance in nature. This element is present in the hydro- and lithosphere, and is also part of minerals: natural and associated gas, peat, oil, coal, oil shale. It is difficult to imagine an adult who would not know that hydrogen is an integral part of water.

In addition, this non-metal is found in animal organisms in the form nucleic acids, proteins, carbohydrates, fats. On our planet, this element is found in free form quite rarely, perhaps only in natural and volcanic gas.

In the form of plasma, hydrogen makes up about half the mass of stars and the Sun, and is also part of the interstellar gas. For example, in free form, as well as in the form of methane, ammonia, this non-metal is present in comets and even some planets.

Physical properties

Before considering the chemical properties of hydrogen, we note that at normal conditions it is a gaseous substance lighter than air, having several isotopic forms. It is almost insoluble in water and has a high thermal conductivity. Protium, which has a mass number of 1, is considered its lightest form. Tritium, which has radioactive properties, is formed in nature from atmospheric nitrogen when neurons expose it to UV rays.

Features of the structure of the molecule

To consider the chemical properties of hydrogen, the reactions characteristic of it, let us dwell on the features of its structure. This diatomic molecule has a covalent non-polar chemical bond. The formation of atomic hydrogen is possible when active metals interact with acid solutions. But in this form, this non-metal is able to exist only for an insignificant time period, almost immediately it recombines into a molecular form.

Chemical properties

Consider the chemical properties of hydrogen. In most of the compounds that this chemical element forms, it exhibits an oxidation state of +1, which makes it similar to active (alkali) metals. The main chemical properties of hydrogen, characterizing it as a metal:

• interaction with oxygen to form water;
• reaction with halogens, accompanied by the formation of hydrogen halide;
• production of hydrogen sulfide when combined with sulfur.

Below is the reaction equation that characterizes the chemical properties of hydrogen. We draw attention to the fact that as a non-metal (with an oxidation state of -1), it acts only in the reaction with active metals, forming the corresponding hydrides with them.

Hydrogen at ordinary temperature does not actively interact with other substances, so most of the reactions are carried out only after preheating.

Let us dwell in more detail on some chemical interactions of the element that heads the periodic table chemical elements Mendeleev.

The reaction of water formation is accompanied by the release of 285.937 kJ of energy. At elevated temperatures (more than 550 degrees Celsius), this process is accompanied by a strong explosion.

Among those chemical properties gaseous hydrogen, which have found significant application in industry, its interaction with metal oxides is of interest. It is by catalytic hydrogenation in modern industry that metal oxides are processed, for example, pure metal is isolated from iron scale (mixed iron oxide). This method allows for efficient processing of scrap metal.

The synthesis of ammonia, which involves the interaction of hydrogen with atmospheric nitrogen, is also in demand in the modern chemical industry. Among the conditions for the occurrence of this chemical interaction, we note pressure and temperature.

Conclusion

Hydrogen is the least active chemical normal conditions. As the temperature rises, its activity increases significantly. This substance is in demand in organic synthesis. For example, by hydrogenation, ketones can be reduced to secondary alcohols, and aldehydes can be converted to primary alcohols. In addition, by hydrogenation, unsaturated hydrocarbons of the ethylene and acetylene classes can be converted into saturated compounds of the methane series. Hydrogen is rightly considered a simple substance in demand in modern chemical production.

• Designation - H (Hydrogen);
• Latin name - Hydrogenium;
• Period - I;
• Group - 1 (Ia);
• Atomic mass - 1.00794;
• Atomic number - 1;
• Radius of an atom = 53 pm;
• Covalent radius = 32 pm;
• The distribution of electrons - 1s 1;
• melting point = -259.14°C;
• boiling point = -252.87°C;
• Electronegativity (according to Pauling / according to Alpred and Rochov) \u003d 2.02 / -;
• Oxidation state: +1; 0; -1;
• Density (n.a.) \u003d 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. This is the simplest element in nature - a hydrogen atom has a nucleus and one electron, probably for this reason hydrogen is the most common element in the universe (more than half the mass of most stars).

About hydrogen, we can say that "the spool is small, but expensive." Despite its "simplicity", hydrogen gives energy to all living beings on Earth - there is a continuous thermonuclear reaction 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 earth's crust the mass fraction of hydrogen is only 0.15%. Meanwhile, the vast majority (95%) of all known on Earth chemical substances 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, showing 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, takes on its only s-orbital one more electron, thus trying to complete its electron layer, showing an oxidation state of -1 (less often), forming more often an ionic bond (see Ionic bond), since the difference in the electronegativity of a hydrogen atom and a metal atom can be quite large.

H2

In the gaseous state, hydrogen is in the form of diatomic molecules, forming a non-polar 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 in platinum and palladium);
• difficult to liquefy (because of its low polarizability);
• has the highest thermal conductivity of all known gases;
• when heated, it reacts with many non-metals, showing 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, showing oxidizing properties: H 2 + Ca = CaH 2;

In compounds, hydrogen exhibits its reducing properties much more strongly than oxidizing ones. Hydrogen is the strongest reducing agent after coal, aluminum and calcium. The reducing properties of hydrogen are widely used in industry to obtain metals and non-metals (simple substances) from oxides and gallides.

Fe 2 O 3 + 3H 2 \u003d 2Fe + 3H 2 O

Reactions of hydrogen with simple substances

Hydrogen accepts an electron, playing the 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 \u003d 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 \u003d 2H +1 Cl
• With fluorine: H 2 0 + F 2 \u003d 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 the role oxidizing agent, in reactions with alkaline And alkaline earth metals to form metal hydrides - salt-like ionic compounds containing hydride ions H - are unstable crystalline substances of white color.

Ca + H 2 \u003d CaH 2 -1 2Na + H 2 0 \u003d 2NaH -1

It is uncommon for hydrogen to exhibit an oxidation state of -1. Reacting with water, hydrides decompose, reducing water to hydrogen. The reaction of calcium hydride with water is as follows:

CaH 2 -1 + 2H 2 +1 0 \u003d 2H 2 0 + Ca (OH) 2

Reactions of hydrogen with complex substances

• at high temperature, hydrogen reduces many metal oxides: ZnO + H 2 \u003d Zn + H 2 O
• methyl alcohol is obtained as a result of the reaction of hydrogen with carbon monoxide (II): 2H 2 + CO → CH 3 OH
• in hydrogenation reactions, hydrogen reacts with many organic substances.

More detailed equations chemical reactions hydrogen and its compounds are discussed on the page "Hydrogen and its compounds - equations of chemical reactions involving hydrogen".

Application 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 matter, 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, a 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, balloons, airships;
• As a fuel, hydrogen is used mixed with CO.

In recent years, scientists have paid much attention to the search for alternative sources renewable energy. One of the promising areas is "hydrogen" energy, in which hydrogen is used as a 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 steam (t=500°C) on a Fe 2 O 3 catalyst: CO + H 2 O = CO 2 + H 2 ;
• thermal decomposition of methane: CH 4 \u003d C + 2H 2;
• gasification of solid fuels (t=1000°C): C + H 2 O = CO + H 2 ;
• electrolysis of water (a very expensive method in which very pure hydrogen is obtained): 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 \u003d ZCl 2 + H 2; Zn + H 2 SO 4 \u003d ZnSO 4 + H 2;
• the interaction of water vapor with hot iron shavings: 4H 2 O + 3Fe \u003d Fe 3 O 4 + 4H 2.

General scheme "HYDROGEN"

I. Hydrogen is a chemical element

a) Position in the RESP

• serial number №1
• period 1
• group I (main subgroup "A")
• relative mass Ar(H)=1
• Latin name Hydrogenium (giving birth to water)

b) The prevalence of hydrogen in nature

Hydrogen is a chemical element.	In the earth's crust(lithosphere and hydrosphere) – 1% by weight (10th place among all elements)
	ATMOSPHERE - 0.0001% by number of atoms
	The most common element in the universe – 92% of all atoms (the main constituent of stars and interstellar gas)

Hydrogen - chemical element	In connections	H 2 O - water(11% by weight)
		CH 4 - methane gas(25% by weight)
		organic matter(oil, combustible natural gases and others) In animal and plant organisms(that is, in the composition of proteins, nucleic acids, fats, carbohydrates and others) In the human body on average contains about 7 kilograms of hydrogen.

c) Hydrogen valency in compounds

II. Hydrogen is a simple substance (H 2)

Receipt

1.Laboratory (Kipp apparatus) A) The interaction of metals with acids: Zn+ 2HCl \u003d ZnCl 2 + H 2 salt B) Interaction of active metals with water: 2Na + 2H 2 O \u003d 2NaOH + H 2 base

2. Industry · water electrolysis email current 2H 2 O \u003d 2H 2 + O 2 · From natural gas t, Ni CH 4 + 2H 2 O \u003d 4H 2 + CO 2

Finding hydrogen in nature.

Hydrogen is widely distributed in nature, its content in the earth's crust (lithosphere and hydrosphere) is 1% by mass, and 16% by the number of atoms. Hydrogen is part of the most common substance on Earth - water (11.19% Hydrogen by mass), in the compounds that make up coals, oil, natural gases, clays, as well as animal and plant organisms (that is, in the composition of proteins, nucleic acids , fats, carbohydrates, etc.). Hydrogen is extremely rare in the free state; it is found in small amounts in volcanic and other natural gases. Negligible amounts of free Hydrogen (0.0001% by number of atoms) are present in the atmosphere. In near-Earth space, Hydrogen in the form of a stream of protons forms an internal ("proton") radiation belt Earth. Hydrogen is the most abundant element in space. In the form of plasma, it makes up about half the mass of the Sun and most stars, the bulk of the gases of the interstellar medium and gaseous nebulae. Hydrogen is present in the atmosphere of a number of planets and in comets in the form of free H 2 , methane CH 4 , ammonia NH 3 , water H 2 O, and radicals. In the form of a stream of protons, Hydrogen is part of the corpuscular radiation of the Sun and cosmic rays.

There are three isotopes of hydrogen:
a) light hydrogen - protium,
b) heavy hydrogen - deuterium (D),
c) superheavy hydrogen - tritium (T).

Tritium is an unstable (radioactive) isotope, so it practically does not occur in nature. Deuterium is stable, but it is very small: 0.015% (of the mass of all terrestrial hydrogen).

Hydrogen valency in compounds

In compounds, hydrogen exhibits valence I.

Physical properties of hydrogen

A simple substance hydrogen (H 2) is a gas, lighter than air, colorless, odorless, tasteless, t kip \u003d - 253 0 C, hydrogen is insoluble in water, combustible. Hydrogen can be collected by displacing air from a test tube or water. In this case, the tube must be turned upside down.

Getting hydrogen

In the laboratory, hydrogen is produced by the reaction

Zn + H 2 SO 4 \u003d ZnSO 4 + H 2.

Iron, aluminum and some other metals can be used instead of zinc, and some other dilute acids can be used instead of sulfuric acid. The resulting hydrogen is collected in a test tube by the method of water displacement (see Fig. 10.2 b) or simply in an inverted flask (Fig. 10.2 a).

In industry, hydrogen is obtained in large quantities from natural gas (mainly methane) by interacting with water vapor at 800 °C in the presence of a nickel catalyst:

CH 4 + 2H 2 O \u003d 4H 2 + CO 2 (t, Ni)

or treated at high temperature with water vapor coal:

2H 2 O + C \u003d 2H 2 + CO 2. (t)

Pure hydrogen is obtained from water by decomposing it electric shock(subjected to electrolysis):

2H 2 O \u003d 2H 2 + O 2 (electrolysis).

Chemical properties of hydrogen

Under normal conditions, molecular Hydrogen is relatively inactive, combining directly with only the most active nonmetals (with fluorine, and in the light also with chlorine). However, when heated, it reacts with many elements.

Hydrogen reacts with simple and complex substances:

- Interaction of hydrogen with metals leads to the formation of complex substances - hydrides, in the chemical formulas of which the metal atom always comes first:

At high temperature, hydrogen reacts directly with some metals(alkaline, alkaline earth and others), forming white crystalline substances - metal hydrides (Li H, Na H, KH, CaH 2, etc.):

H 2 + 2Li = 2LiH

Metal hydrides are easily decomposed by water with the formation of the corresponding alkali and hydrogen:

Sa H 2 + 2H 2 O \u003d Ca (OH) 2 + 2H 2

- When hydrogen interacts with non-metals volatile hydrogen compounds are formed. IN chemical formula volatile hydrogen compound, the hydrogen atom can be either in the first or in the second place, depending on the location in the PSCE (see the plate in the slide):

1). With oxygen Hydrogen forms water:

Video "Combustion of hydrogen"

2H 2 + O 2 \u003d 2H 2 O + Q

At ordinary temperatures, the reaction proceeds extremely slowly, above 550 ° C - with an explosion (a mixture of 2 volumes of H 2 and 1 volume of O 2 is called explosive gas) .

Video "Explosion of explosive gas"

Video "Preparation and explosion of an explosive mixture"

2). With halogens Hydrogen forms hydrogen halides, for example:

H 2 + Cl 2 \u003d 2HCl

Hydrogen explodes with fluorine (even in the dark and at -252°C), reacts with chlorine and bromine only when illuminated or heated, and with iodine only when heated.

3). With nitrogen Hydrogen reacts with the formation of ammonia:

ZN 2 + N 2 \u003d 2NH 3

only on a catalyst and at elevated temperatures and pressures.

4). When heated, hydrogen reacts vigorously with sulfur:

H 2 + S \u003d H 2 S (hydrogen sulfide),

much more difficult with selenium and tellurium.

5). with pure carbon Hydrogen can react without a catalyst only at high temperatures:

2H 2 + C (amorphous) = CH 4 (methane)

- Hydrogen enters into a substitution reaction with metal oxides , while water is formed in the products and the metal is reduced. Hydrogen - exhibits the properties of a reducing agent:

Hydrogen is used for the recovery of many metals, since it takes away oxygen from their oxides:

Fe 3 O 4 + 4H 2 \u003d 3Fe + 4H 2 O, etc.

Application of hydrogen

Video "Use of hydrogen"

Currently, hydrogen is produced in huge quantities. A very large part of it is used in the synthesis of ammonia, the hydrogenation of fats and the hydrogenation of coal, oils and hydrocarbons. In addition, hydrogen is used for the synthesis of hydrochloric acid, methyl alcohol, hydrocyanic acid, in welding and forging metals, as well as in the manufacture of incandescent lamps and precious stones. Hydrogen goes on sale in cylinders under pressure over 150 atm. They are painted dark green and are supplied with a red inscription "Hydrogen".

Hydrogen is used to convert liquid fats into solid fats (hydrogenation), to produce liquid fuels by hydrogenating coal and fuel oil. In metallurgy, hydrogen is used as a reducing agent for oxides or chlorides to produce metals and non-metals (germanium, silicon, gallium, zirconium, hafnium, molybdenum, tungsten, etc.).

The practical application of hydrogen is diverse: it is usually filled with balloons, in the chemical industry it serves as a raw material for the production of many very important products (ammonia, etc.), in the food industry - for the production of solid fats from vegetable oils, etc. High temperature (up to 2600 °C), obtained by burning hydrogen in oxygen, is used to melt refractory metals, quartz, etc. Liquid hydrogen is one of the most efficient jet fuels. The annual world consumption of hydrogen exceeds 1 million tons.

SIMULATORS

No. 2. Hydrogen

TASKS FOR REINFORCEMENT

Task number 1
Make up the equations for the reactions of the interaction of hydrogen with the following substances: F 2 , Ca, Al 2 O 3 , mercury oxide (II), tungsten oxide (VI). Name the reaction products, indicate the types of reactions.

Task number 2
Carry out the transformations according to the scheme:
H 2 O -> H 2 -> H 2 S -> SO 2

Task number 3.
Calculate the mass of water that can be obtained by burning 8 g of hydrogen?