Chemical properties of hydrogen: features and application. Oxygen and its properties. Oxygen compounds with hydrogen

The most common element in the universe is hydrogen. In the stars substance, it has the type of nuclei - protons - and is a material for thermonuclear processes. Almost half of the mass of the Sun also consists of H 2 molecules. Its content in the earth's crust reaches 0.15%, and atoms are present in the composition of oil, natural gas, water. Together with oxygen, nitrogen and carbon, it is an organogenic element that is part of all living organisms on Earth. In our article, we will explore the physical and chemical properties of hydrogen, we define the main areas of its use in industry and significance in nature.

Position in the periodic system of chemical elements of Mendeleev

The first element opening the periodic system is hydrogen. Its atomic mass is 1.0079. It has two stable (diet and deuterium) and one radioactive isotope (tritium). Physical properties are determined by the place of nonmetal in the table of chemical elements. Under normal conditions, hydrogen (its formula - H 2) represents gas, which is almost 15 times lighter than air. The structure of an element atom is unique: it consists only of kernel and one electron. The molecule of the substance is ductomic, the particles in it are connected using a covalent non-polar connection. Its energy intensity is large enough - 431 kJ. This explains the low chemical activity of the compound under normal conditions. The electronic formula of hydrogen is as follows: H: h.

The substance has another number of properties, which are no analogues among other non-metals. Consider some of them.

Solubility and thermal conductivity

Metals are best carried out best, but hydrogen in thermal conductivity is approaching them. The explanation of the phenomenon is a very high speed of thermal motion of light molecules of substance, so in the hydrogen atmosphere, the heated object cools 6 times faster than in air. The compound can be disassembled well in metals, for example, almost 900 hydrogen volumes can be absorbed by one palladium volume. Metals can enter with H 2 to chemical reactions in which the oxidative properties of hydrogen are manifested. In this case, hydrides are formed:

2NA + H 2 \u003d 2 Nah.

In this reaction, the atoms of the element receive electrons from the metal particles, turning into anon with a single negative charge. A simple substance H 2 in this case is an oxidizing agent, which is usually not typical for it.

Hydrogen as a reducing agent

Unites metals and hydrogen not only high thermal conductivity, but also the ability of their atoms in chemical processes to give their own electrons, that is, oxidized. For example, the main oxides come into reaction with hydrogen. The redox reaction ends with the release of pure metal and the formation of water molecules:

Cuo + H 2 \u003d Cu + H 2 O.

The interaction of the oxygen substance with heating also leads to the preparation of water molecules. The process is exothermic and is accompanied by the release of a large number of thermal energy. If the gas mixture of H 2 and O 2 responds in a 2: 1 ratio, then it is called it as it explodes when the ignition:

2H 2 + O 2 \u003d 2H 2 O.

Water is and plays a crucial role in the formation of the Earth's hydrosphere, climate, weather. It provides a circulation of elements in nature, supports all the vital processes of organisms - the inhabitants of our planet.

Interaction with non-metals

The most important chemical properties of hydrogen is its reactions with non-metallic elements. Under normal conditions, it is sufficiently chemically inert, so the substance can react only with halogens, for example, with fluorine or chlorine, which are most active among all non-metals. Thus, a mixture of fluorine and hydrogen explodes in the dark or in the cold, and with chlorine - when heated or in light. The reaction products will be halogen breeds, the aqueous solutions of which are known as fluoride and chloride acids. C interacts at 450-500 degrees, 30-100 MPa pressure and in the presence of a catalyst:

N₂ + 3H₂ ⇔ P, T, KAT ⇔ 2NH₃.

The considered chemical properties of hydrogen are of great importance for industry. For example, you can get a valuable chemical product - ammonia. It is the main raw material for obtaining nitrate acid and nitrogen fertilizers: carbamide, ammonium nitrate.

Organic substances

Between carbon and hydrogen leads to the preparation of the simplest hydrocarbon - methane:

C + 2H 2 \u003d CH 4.

The substance is an essential part of the natural and they are used as a valuable type of fuel and raw materials for the industry of organic synthesis.

In the chemistry of carbon compounds, the element is part of a huge amount of substances: alkanans, alkenes, carbohydrates, alcohols, etc. There are many reactions of organic compounds with H 2 molecules. They wear a general name - hydrogenation or hydrogenation. So, aldehydes can be restored to hydrogen to alcohols, unsaturated hydrocarbons - to alkanov. For example, ethylene turns into Ethan:

C 2 H 4 + H 2 \u003d C 2 H 6.

Such chemical properties of hydrogen are important, such as the hydrogenation of liquid oils: sunflower, corn, rapeseed. It leads to solid fat - Salomas, which is used in the production of glycerin, soap, stearin, margarine solid varieties. To improve the appearance and taste of the food product, milk, animal fats, sugar, vitamins are added to it.

In our article, we studied the properties of hydrogen and found out his role in the nature and life of a person.

Hydrogen was opened in the second half of the 18th century English scientists in the field of physics and chemistry of Cavendish. He managed to highlight the substance in its pure state, he studied it and described the properties.

Such is the history of the opening of hydrogen. During the experiments, the researcher determined that this is a combustible gas, the combustion of which in the air gives water. This led to the definition of high-quality water composition.

What is hydrogen

About hydrogen, as a simple substance, for the first time, the French chemist A. Lavoisier in 1784, since it determined that the atoms of one species were part of its molecule.

The name of the chemical element of Latin sounds like Hydrogenium (read "hydrogenium"), which means "water-feeding". The name refers to the combustion reaction, as a result of which water is formed.

Hydrogen characteristic

The designation of hydrogen N. Mendeleev assigned this chemical element the first sequence number, placing it in the main subgroup of the first group and the first period and conditionally in the main subgroup of the seventh group.

Atomic weight (atomic weight) of hydrogen is 1.00797. The molecular weight H 2 is 2 a. e. Molar mass is numerically equal to her.

Presents three isotopes that have a special name: the most common diet (H), severe deuterium (D), radioactive tritium (T).

This is the first element that can be completely divided into isotopes in a simple way. It is based on a high difference of masters of isotopes. The process was first implemented in 1933. It is explained by the fact that only in 1932 an isotope was revealed with a mass 2.

Physical properties

Under normal conditions, a simple substance of hydrogen in the form of two-heed molecules is gas, without color, which has no taste and smell. Little soluble in water and other solvents.

Crystallization temperature - 259.2 o C, Boiling point - 252.8 o C. The diameter of hydrogen molecules is so small that they have the ability to slow diffusion through a number of materials (rubber, glass, metals). This property finds use when it is necessary to clean hydrogen from gaseous impurities. With n. y Hydrogen has a density equal to 0.09 kg / m3.

Is it possible to transform hydrogen into metal by analogy with elements located in the first group? Scientists have established that hydrogen under conditions when the pressure is approaching 2 million atmospheres, begins to absorb infrared rays, which indicates the polarization of the substance molecules. Perhaps with even higher pressures, hydrogen will become a metal.

It is interesting: There is an assumption that on planets-giants, Jupiter and Saturn, hydrogen is in the form of a metal. It is assumed that metallic solid hydrogen is also present in the composition of the terrestrial nucleus, due to the ultrahigh pressure generated by the earth's mantle.

Chemical properties

In chemical interaction with hydrogen, both simple and complex substances enter. But the small activity of hydrogen is required to increase the creation of appropriate conditions - an increase in temperature, the use of catalysts, etc.

When heated to the reaction with hydrogen, such simple substances are entering such as oxygen (O 2), chlorine (Cl 2), nitrogen (N 2), sulfur (S).

If you set fire to clean hydrogen at the end of the gas pipe in the air, it will burn smoothly, but barely noticeably. If you place the gas feed tube into the atmosphere of pure oxygen, then the combustion will continue with the formation of water droplets on the walls of the vessel, as the result of the reaction:

The burning of water is accompanied by the release of a large amount of heat. This is an exothermic compound reaction, in the process of which hydrogen is oxidized by oxygen to form H 2 O oxide. It is also a redox reaction in which hydrogen is oxidized, and oxygen is restored.

Similarly, a reaction with CL 2 with the formation of chloroodorodor.

To implement the interaction of nitrogen with hydrogen, high temperature is required and increased pressure, as well as the presence of a catalyst. The result is ammonia.

As a result of the reaction with sulfur, hydrogen sulfide is formed, the recognition of which facilitates the characteristic smell of rotten eggs.

The degree of hydrogen oxidation in these reactions is +1, and in the hydrides described below, 1.

When reactions with some metals, hydrides are formed, for example, sodium hydride - NaH. Some of these complex compounds are used as fuel for missiles, as well as in thermonuclear energy.

Hydrogen reacts with substances from the complex category. For example, with copper oxide (II), Cuo formula. To carry out the reaction, the hydrogen of the copper is passed above the heated powdered copper oxide (II). During the interaction, the reagent changes its color and becomes red-brown, and on the cold walls of the test tubes, water droplets are settled.

The hydrogen during the reaction is oxidized, forming water, and copper is restored from oxide to a simple substance (CU).

Areas of use

Hydrogen is of great importance for a person and finds use in a variety of spheres:

1. In chemical production is raw materials, in other industries - fuel. Do not cost without hydrogen and enterprises of petrochemistry and refining.
2. In the electric power industry, this simple substance performs the function of the cooling agent.
3. In black and non-ferrous metallurgy, hydrogen shall be given the role of the reducing agent.
4. To create an inert medium when packing products.
5. The pharmaceutical industry - uses hydrogen as a reagent in the production of hydrogen peroxide.
6. This light gas fill meteorological probes.
7. Known this element and as a fuel reducing agent for rocket engines.

Scientists unanimously prophesy to hydrogen fuel palm championship in power engineering.

Receipt in industry

In industry, hydrogen is obtained by electrolysis, which is subjected to chlorides or alkali metal hydroxides dissolved in water. You can also get hydrogen in this way directly from the water.

Used for these purposes conversion of coke or methane with water vapor. The decomposition of methane at elevated temperature also gives hydrogen. Fractional gas liquefaction with a fractional method is also used for industrial hydrogen production.

Getting in the laboratory

The laboratory for hydrogen is used by the Cypa apparatus.

Salt or sulfuric acid and zinc protrude as reagents. As a result of the reaction, hydrogen is formed.

Finding hydrogen in nature

Hydrogen more often occurs in the universe. The main mass of the stars, including the sun, and other cosmic bodies is hydrogen.

In the earth's crust of it only 0.15%. It is present in many minerals, in all organic substances, as well as in water covering on 3/4 surface of our planet.

In the upper layers of the atmosphere, it is possible to detect traces of hydrogen in its pure form. Find it in a number of combustible natural gases.

Gaseous hydrogen is the most loose, and the liquid is the most dense substance on our planet. With hydrogen, you can change the voice of the voice, if you breathe it, and to speak out.

The basis of the most powerful hydrogen bomb is the splitting of the easiest atom.

Hydrogen is gas, it is he in the first place in the periodic system. The name of this widespread element in the nature of the Latin means "generating water". So what physical and chemical properties of hydrogen are known to us?

Hydrogen: General Information

Under normal conditions, hydrogen has no taste, no smell, nor colors.

Fig. 1. Formula of hydrogen.

Since the atom has one energy electron level, on which there may be a maximum of two electrons, then for a stable state, an atom can be accepted as one electron (the degree of oxidation -1), so to give one electron (the degree of oxidation +1), showing constant valence I . That is why the hydrogen element symbol is placed not only in the IA group (the main subgroup I group) together with alkaline metals, but also in the VIIIA group (the main subgroup of the group VII) together with halogens. Halogen atoms are also lacking one electron before filling out the external level, and they, like hydrogen, are non-metals. Hydrogen shows a positive degree of oxidation in compounds, where it is associated with more electronegative elements - non-metals, and the negative degree of oxidation is in compounds with metals.

Fig. 2. The location of hydrogen in the periodic system.

At hydrogen, there are three isotopes, each of which has its own name: participants, deuterium, tritium. The number of latter on earth is negligible.

Chemical properties of hydrogen

In a simple substance H 2, the connection between the atoms is durable (bond energy 436 kJ / mol), therefore the activity of molecular hydrogen is small. Under normal conditions, it interacts only with very active metals, and the only non-metallol with which hydrogen enters into the reaction is fluorine:

F 2 + H 2 \u003d 2HF (fluoride hydrogen)

With other simple (metals and non-metals) and complex (oxides, organic uncertain compounds), hydrogen substances react to either when irradiated and increasing the temperature or in the presence of a catalyst.

Hydrogen burns in oxygen with highlighting a significant amount of heat:

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

A mixture of hydrogen with oxygen (2 hydrogen volumes and 1 oxygen volume) when the ignition is strongly exploded and therefore wears the name of the rattling gas. When working with hydrogen, the safety regulations should follow.

Fig. 3. REDUCH GAS.

In the presence of catalysts, gas can react with nitrogen:

3H 2 + N 2 \u003d 2NH 3

- in this reaction at elevated temperatures and pressure in the industry, ammonia is obtained.

In high temperature conditions, hydrogen is capable of reacting with gray, selenium, tellurium. And when interacting with alkaline and alkaline earth metals, hydrides are formulated:

- In this case, hydrogen plays the role of the oxidant.

Hydrogen has a feature while increasing the temperature to restore oxides of many metals, as a result of which water is formed. For example:

Cuo + H 2 \u003d H 2 O + Cu

- In this process, hydrogen is a reducing agent4.3. Total ratings obtained: 70.

Oxygen is the most common element on Earth. Together with nitrogen and insignificant number of other gases, free oxygen forms the atmosphere of the Earth. Its content in the air is 20.95% by volume or 23.15% by weight. In the earth's crust, 58% of atoms are atoms of bound oxygen (47% by weight). Oxygen is part of the water (reserves of bound oxygen in the hydrosphere are exceptionally large), rocks, many minerals and salts, contains in fats, proteins and carbohydrates, from which living organisms consist. Practically all free oxygen of the Earth arose and persisted as a result of the photosynthesis process.

Physical properties.

Oxygen - gas without color, taste and odor, a little heavier air. In the water, a small solvent (in 1 liter of water at 20 degrees, 31 ml of oxygen is dissolved), but still better than other atmospheric gases, therefore water is enriched with oxygen. The density of oxygen under normal conditions is 1.429g / l. At temperatures -183 0 C and a pressure of 101,325 kPa oxygen goes into a liquid state. Liquid oxygen has a bluish color, draws into a magnetic field, and at -218.7 ° C, forms blue crystals.

Natural oxygen has three isotop about 16, about 17, about 18.

Allotropy- the ability of the chemical element to exist in the form of two or several simple substances, differing only in the number of atoms in the molecule or the structure.

Ozone about 3 - exists in the upper layers of the atmosphere at an altitude of 20-25 km from the surface of the Earth and forms the so-called "ozone layer", which protects the Earth from the destructive ultraviolet radiation of the Sun; Pale violet, poisonous in large quantities with a specific, sharp, but pleasant smell. The melting point is - 192.7 0 s, the boiling point-111.9 0 C. In water, soluble is better than oxygen.

Ozone is a strong oxidizing agent. Its oxidative activity is based on the ability of the molecule to decompose with the release of atomic oxygen:

It oxidizes many simple and complex substances. With some metals, ozonides forms, for example, Potassia Ozonide:

K + O 3 \u003d KO 3

Ozone is obtained in special devices - ozonomators. In them, under the action of an electrical discharge, the conversion of molecular oxygen into ozone:

A similar reaction occurs under the action of thunderstorms.

The use of ozone is due to its strong oxidative properties: it is used to whiten the tissues, disinfection of drinking water, in medicine as a disinfectant.

Inhalation of ozone in large quantities is harmful: it is annoying the mucous membranes of the eyes and the respiratory organs.

Chemical properties.

In chemical reactions with atoms of other elements (except fluorine), oxygen exhibits exclusively oxidative properties

The most important chemical property is the ability to form oxides with almost all the elements. At the same time, with most substances, oxygen reacts directly, especially when heated.

As a result of these reactions, as a rule, oxides are formed, less often - peroxides:

2SA + O 2 \u003d 2SAO

2VA + O 2 \u003d 2VAO

2NA + O 2 \u003d Na 2 O 2

Oxygen does not interact directly with halogens, gold, platinum, their oxides are indirectly obtained. When sulfur heated, carbon, phosphorus burn in oxygen.

The interaction of oxygen with nitrogen begins only at a temperature of 1200 0 s or in an electric discharge:

N 2 + O 2 \u003d 2NO

With hydrogen oxygen forms water:

2N 2 + O 2 \u003d 2N 2

In the process of this reaction, a significant amount of heat is highlighted.

A mixture of two hydrogen volumes with one oxygen during the ignition explodes; It is called a rattled gas.

Many metals in contact with air oxygen are destroyed - corrosion. Some metals under normal conditions are oxidized only from the surface (for example, aluminum, chromium). The resulting oxide film prevents further interaction.

4Al + 3O 2 \u003d 2AL 2 O 3

Complicated substances under certain conditions also interact with oxygen. At the same time, oxides are formed, and in some cases - oxides and simple substances.

CH 4 + 2O 2 \u003d CO 2 + 2N 2

H 2 S + O 2 \u003d 2SO 2 + 2N 2

4NN 3 + ZO 2 \u003d 2N 2 + 6N 2

4CH 3 NH 2 + 9O 2 \u003d 4CO 2 + 2N 2 + 10H 2 O

When interacting with complex substances, oxygen acts as an oxidizing agent. On oxidative activity of oxygen, its important property is based - the ability to support combustionsubstances.

The oxygen with hydrogen also forms a compound - hydrogen peroxide H 2 O 2 is a colorless transparent liquid with a burning astringent taste, well soluble in water. In the chemical ratio of hydrogen peroxide is a very interesting connection. It is characterized by its low stability: when standing, slowly decomposes on water and oxygen:

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

Light, heating, alkali presence, contact with oxidizing agents or reducing agents accelerate the decomposition process. The degree of oxidation of oxygen in hydrogen peroxide \u003d - 1, i.e. It has an intermediate value between the degree of oxidation of oxygen in water (-2) and in molecular oxygen (0), so hydrogen peroxide exhibits redox duality. The oxidative properties of hydrogen peroxide are much stronger than reducing, and they appear in acidic, alkaline and neutral media.

H 2 O 2 + 2KI + H 2 SO 4 \u003d K 2 SO 4 + I 2 + 2H 2 O

Definition

Hydrogen - The first element of the periodic system of chemical elements D.I. Mendeleeva. Symbol - N.

Atomic mass - 1 A.E.M. Hydrogen molecule DVOTOMEN - H 2.

Electronic configuration of hydrogen atom - 1s 1. Hydrogen refers to the S-elements family. In its compounds, there is an oxidation degree -1, 0, +1. Natural hydrogen consists of two stable isotopes - Passions 1 H (99.98%) and deuterium 2 H (d) (0.015%) - and radioactive isotop of tritium 3 H (t) (trace amounts, half-life - 12.5 years) .

Chemical properties of hydrogen

Under normal conditions, molecular hydrogen exhibits a relatively low reaction capacity, which is explained by the high strength of ties in the molecule. When heated, it takes into account almost with all the simple substances formed by the elements of the main subgroups (except for noble gases, b, si, p, al). In chemical reactions, it can act as as a reducing agent (more often) and oxidizing agent (less often).

Hydrogen exhibits properties of the reducing agent (H 2 0 -2E → 2N +) in the following reactions:

1. Reactions of interaction with simple substances - non-metals. Hydrogen reacts with halogen, moreover, the reaction of interaction with fluorine under normal conditions, in the dark, with an explosion, with chlorine - when illuminated (or UV irradiation) on the chain mechanism, with bromine and iodine only when heated; oxygen (a mixture of oxygen and hydrogen in volume ratio 2: 1 is called "Razmu Gas"), gray, nitrogen and carbon:

H 2 + Hal 2 \u003d 2hhal;

2H 2 + O 2 \u003d 2H 2 O + Q (T);

H 2 + S \u003d H 2 S (T \u003d 150 - 300C);

3H 2 + N 2 ↔ 2NH 3 (T \u003d 500C, P, KAT \u003d FE, PT);

2H 2 + C ↔ CH 4 (T, P, KAT).

2. Reactions of interaction with complex substances. Hydrogen reacts with low-effective metal oxides, moreover, it is able to restore only metals in a row of activity to the right of zinc:

Cuo + H 2 \u003d Cu + H 2 O (T);

Fe 2 O 3 + 3H 2 \u003d 2Fe + 3H 2 O (T);

WO 3 + 3H 2 \u003d W + 3H 2 O (T).

Hydrogen reacts with non-metal oxides:

H 2 + CO 2 ↔ CO + H 2 O (T);

2H 2 + CO ↔ CH 3 OH (T \u003d 300C, P \u003d 250 - 300 ATM., KAT \u003d ZNO, CR 2 O 3).

Hydrogen enters the hydrogenation reaction with organic compounds of cycloalkanes, alkenes, arena, aldehydes and ketones, etc. All of these reactions are carried out when heated, under pressure, platinum or nickel are used as catalysts:

CH 2 \u003d CH 2 + H 2 ↔ CH 3 -CH 3;

C 6 H 6 + 3H 2 ↔ C 6 H 12;

C 3 H 6 + H 2 ↔ C 3 H 8;

CH 3 CHO + H 2 ↔ CH 3 -CH 2 -OH;

CH 3 -CO-CH 3 + H 2 ↔ CH 3 -CH (OH) -CH 3.

Hydrogen as an oxidizing agent (H 2 + 2E → 2N -) acts in the reactions of interaction with alkaline and alkaline earth metals. At the same time, hydrides are formed - crystalline ionic compounds in which hydrogen shows the degree of oxidation -1.

2NA + H 2 ↔ 2NAH (T, P).

CA + H 2 ↔ CAH 2 (T, P).

Physical properties of hydrogen

Hydrogen - light colorless gas, odorless, density at N.U. - 0.09 g / l, 14.5 times lighter than air, T kip \u003d -252.8s, T pl \u003d - 259.2С. Hydrogen is poorly soluble in water and organically solvents, well soluble in some metals: nickel, palladium, platinum.

According to modern Cosmochemistry, hydrogen is the most common element of the universe. The main form of the existence of hydrogen in outer space is separate atoms. According to the prevalence on Earth, hydrogen ranks 9th among all the elements. The main amount of hydrogen on the ground is in the associated state - in the composition of water, oil, natural gas, stone coal, etc. In the form of a simple substance, hydrogen occurs rarely - in the composition of volcanic gases.

Obtaining hydrogen

Laboratory and industrial methods for producing hydrogen are distinguished. Laboratory methods include the interaction of metals with acids (1), as well as the interaction of aluminum with an aqueous solutions of alkalis (2). Among the industrial methods of obtaining hydrogen, the electrolysis of the aqueous solutions of alkali and salts (3) and the methane conversion (4) play a major role.

Zn + 2HCl \u003d ZnCl 2 + H 2 (1);

2AL + 2NAOH + 6H 2 O \u003d 2NA +3 H 2 (2);

2NACL + 2H 2 O \u003d H 2 + CL 2 + 2NAOH (3);

CH 4 + H 2 O ↔ CO + H 2 (4).

Examples of solving problems

Example 1.

The task	When the interaction of 23.8 g of a metal tin with an excess of hydrochloric acid was distinguished by hydrogen, in an amount sufficient to obtain 12.8 g of metal copper, determine the degree of oxidation of tin in the resulting compound.
Decision	Based on the electronic structure of the tin atom (... 5s 2 5p 2), it can be concluded that two oxidation degrees are characteristic - +2, +4. Based on this, we will make the equation of possible reactions: Sn + 2hcl \u003d H 2 + SNCl 2 (1); SN + 4HCl \u003d 2H 2 + SNCl 4 (2); Cuo + H 2 \u003d Cu + H 2 O (3). We find the amount of copper substance: v (Cu) \u003d M (Cu) / M (Cu) \u003d 12.8 / 64 \u003d 0.2 mol. According to equation 3, the amount of hydrogen substance: v (H 2) \u003d V (Cu) \u003d 0.2 mol. Knowing tin mass, we will find its amount of substance: v (Sn) \u003d M (Sn) / m (Sn) \u003d 23.8 / 119 \u003d 0.2 mol. Compare the amount of tin and hydrogen substance by equation 1 and 2 and under the condition of the problem: v 1 (SN): V 1 (H 2) \u003d 1: 1 (equation 1); v 2 (SN): V 2 (H 2) \u003d 1: 2 (equation 2); v (Sn): V (H 2) \u003d 0.2: 0.2 \u003d 1: 1 (Task condition). Consequently, tin interacts with hydrochloric acid according to equation 1 and the degree of oxidation of tin is +2.
Answer	The degree of oxidation of tin is +2.

Example 2.

The task	The gas, elected under the action of 2.0 g of zinc per 18.7 ml of 14.6% hydrochloric acid (the density of the solution of 1.07 g / ml), was allowed when heated over 4.0 g of copper oxide (II). What is the mass of the resulting solid mixture?
Decision	Under the action of zinc on hydrochloric acid, hydrogen is highlighted: Zn + 2NSL \u003d ZNCL 2 + H 2 (1), which during heating restores copper (II) oxide to copper (2): Cuo + H 2 \u003d Cu + H 2 O. Find quantities of substances in the first reaction: m (p-ra nsl) \u003d 18.7. 1.07 \u003d 20.0 g; m (nsl) \u003d 20.0. 0.146 \u003d 2.92 g; v (nsl) \u003d 2.92 / 36.5 \u003d 0.08 mol; v (Zn) \u003d 2.0 / 65 \u003d 0.031 mol. Zinc is disadvantaged, so the amount of hydrogen distinguished is equal to: v (H 2) \u003d V (zn) \u003d 0.031 mol. In the second reaction, hydrogen is in the disadvantage, since: v (Cuo) \u003d 4.0 / 80 \u003d 0.05 mol. As a result of the reaction, 0.031 mol Cuo will turn into 0.031 mol Cu, and the mass loss will be: m (Cuo) - M (Cu) \u003d 0.031 × 80 - 0.031 × 64 \u003d 0.50 g. The mass of solid mixture of Cuo with Cu after the flow of hydrogen will be: 4.0-0.5 \u003d 3.5 g
Answer	The mass of solid mixture of Cuo with Cu is equal to 3.5 g