Sulfuric acid is strong. Getting hydrogen sulfide. Reactions with simple oxidizing substances

- (hydrogen sulfide) H2S, a colorless gas with a rotten egg odour; tmelt? 85.54 .С, tboil? 60.35 .С; at 0 .C it liquefies under a pressure of 1 MPa. Reducing agent. By-product of oil refining, coal coking, etc.; formed by decomposition... Big Encyclopedic Dictionary

- (H2S), colorless, poisonous gas with a smell of rotten eggs. Formed during decay processes, found in crude oil. Obtained by the action of sulfuric acid on metal sulfides. Used in traditional QUALITATIVE ANALYSIS. Properties: temperature ... ... Scientific and technical encyclopedic dictionary

Hydrogen sulfide, hydrogen sulfide, pl. no, husband. (chem.). A gas formed during the decay of protein substances, emitting the smell of rotten eggs. Dictionary Ushakov. D.N. Ushakov. 1935 1940 ... Explanatory Dictionary of Ushakov

Hydrogen sulfide, a, husband. A colorless gas with a pungent, unpleasant odor resulting from the decomposition of proteins. | adj. hydrogen sulfide, oh, oh. Explanatory dictionary of Ozhegov. S.I. Ozhegov, N.Yu. Shvedova. 1949 1992 ... Explanatory dictionary of Ozhegov

Exist., Number of synonyms: 1 gas (55) ASIS Synonym Dictionary. V.N. Trishin. 2013 ... Synonym dictionary

Colorless poisonous gas H2S with an unpleasant specific odor. Possesses slightly acidic properties. 1 liter C. at t 0 ° C and a pressure of 760 mm is 1.539 g. It is found in oils, in natural waters, in gases of biochemical origin, as ... ... Geological Encyclopedia

hydrogen sulfide- Hydrogen sulfide, H2S (molecular weight 34.07), a colorless gas with a characteristic smell of rotten eggs. A liter of gas under normal conditions (0°, 760 mm) weighs 1.5392 g. Temperature, boiling 62°, melting 83°; S. is part of gaseous secretions ... ... Big Medical Encyclopedia

hydrogen sulfide- — Biotechnology topics EN hydrogen sulfide … Technical Translator's Handbook

hydrogen sulfide- HYDROGEN SULFIDE, a, m A colorless gas with a sharp unpleasant odor, formed during the decomposition of protein substances and which is a combination of sulfur with hydrogen. Hydrogen sulfide is found in some mineral waters and therapeutic muds and is used ... ... Explanatory dictionary of Russian nouns

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hydrogen sulfide (H 2 S) is a highly carcinogenic, toxic gas. It has a strong characteristic smell of rotten eggs.

Getting hydrogen sulfide.

1. In the laboratory H 2 S obtained during the reaction between sulfides and dilute acids:

FeS + 2 HCl = FeCl 2 + H 2 S,

2. Interaction Al 2 S 3 With cold water(the resulting hydrogen sulfide is more pure than in the first production method):

Al 2 S 3 + 6H 2 O \u003d 2Al (OH) 3 + 3H 2 S.

Chemical properties of hydrogen sulfide.

hydrogen sulfide H 2 S - a covalent compound that does not form hydrogen bonds, like a molecule H 2 O. (The difference is that the sulfur atom is larger and more electronegative than the oxygen atom. Therefore, the charge density of sulfur is lower. And due to the lack of hydrogen bonds, the boiling point of H 2 S higher than that of oxygen. Also H 2 S poorly soluble in water, which also indicates the absence of hydrogen bonds).

H 2 S + Br 2 \u003d S + 2HBr,

2. Hydrogen sulfide H 2 S- very weak acid, dissociates stepwise in solution:

H 2 S ⇆ H + + HS - ,

HS - ⇆ H + + S 2- ,

3. Interacts with strong oxidizing agents:

H 2 S + 4Cl 2 + 4H 2 O \u003d H 2 SO 4 + 8HCl,

2 H 2 S + H 2 SO 3 = 3 S + 3 H 2 O,

2 FeCl 3 + H 2 S = 2 FeCl 2 + S + 2 HCl,

4. Reacts with bases, basic oxides and salts, while forming acidic and medium salts (hydrosulfides and sulfides):

Pb(NO 3) 2 + 2S = PbS↓ + 2HNO 3 .

This reaction is used to detect hydrogen sulfide or sulfide ions. PbS- Black sediment.

Hydrogen sulfide (H₂S) is a colorless gas with a rotten egg odor. It is denser than hydrogen. Hydrogen sulfide is deadly poisonous to humans and animals. Even its slight content in the air causes dizziness and nausea, but the worst thing is that with prolonged inhalation, this smell is no longer felt. However, in case of poisoning with hydrogen sulfide, there is a simple antidote: you should wrap a piece of bleach in a scarf, then moisten it, and sniff this bundle for some time. Hydrogen sulfide is obtained by reacting sulfur with hydrogen at a temperature of 350 ° C:

H₂ + S → H₂S

This is a redox reaction: during it, the oxidation states of the elements involved in it change.

Under laboratory conditions, hydrogen sulfide is produced by the action of sulfuric or hydrochloric acid on iron sulfide:

FeS + 2HCl → FeCl₂ + H₂S

This is an exchange reaction: in it, interacting substances exchange their ions. This process is usually carried out using a Kipp apparatus.

Kipp apparatus

Properties of hydrogen sulfide

During the combustion of hydrogen sulfide, sulfur oxide 4 and water vapor are formed:

2H₂S + 3О₂ → 2Н₂О + 2SO₂

H₂S burns with a bluish flame, and if you hold an inverted beaker over it, a transparent condensate (water) will appear on its walls.

However, with a slight decrease in temperature, this reaction proceeds somewhat differently: an already yellowish coating of free sulfur will appear on the walls of a pre-chilled glass:

2H₂S + О₂ → 2Н₂О + 2S

Based on this reaction industrial way receiving sulfur.

When a pre-prepared gaseous mixture of hydrogen sulfide and oxygen is ignited, an explosion occurs.

The reaction of hydrogen sulfide and sulfur oxide (IV) also allows you to get free sulfur:

2H₂S + SO₂ → 2H₂O + 3S

Hydrogen sulfide is soluble in water, and three volumes of this gas can dissolve in one volume of water, forming a weak and unstable hydrosulfide acid (H₂S). This acid is also called hydrogen sulfide water. As you can see, the formulas for hydrogen sulfide gas and hydrosulfide acid are written in the same way.

If a lead salt solution is added to hydrosulfide acid, a black precipitate of lead sulfide will form:

H₂S + Pb(NO₃)₂ → PbS + 2HNO₃

This is a qualitative reaction for the detection of hydrogen sulfide. It also demonstrates the ability of hydrosulfide acid to enter into exchange reactions with salt solutions. Thus, any soluble lead salt is a reagent for hydrogen sulfide. Some other metal sulfides also have a characteristic color, for example: zinc sulfide ZnS - white, cadmium sulfide CdS - yellow, copper sulfide CuS - black, antimony sulfide Sb₂S₃ - red.

By the way, hydrogen sulfide is an unstable gas and, when heated, almost completely decomposes into hydrogen and free sulfur:

H₂S → H₂ + S

Hydrogen sulfide interacts intensively with aqueous solutions halogens:

H₂S + 4Cl₂ + 4H₂O → H₂SO₄ + 8HCl

Hydrogen sulfide in nature and human activity

Hydrogen sulfide is part of volcanic gases, natural gas and gases associated with oil fields. There is also a lot of it in natural mineral waters, for example, in the Black Sea, it occurs at a depth of 150 meters and below.

Hydrogen sulfide is used:

in medicine (treatment with hydrogen sulfide baths and mineral waters);
in industry (obtaining sulfur, sulfuric acid and sulfides);
in analytical chemistry(for precipitation of sulfides heavy metals, which are usually insoluble);
in organic synthesis (to obtain sulfur analogues of organic alcohols (mercaptans) and thiophene (sulfur-containing aromatic hydrocarbon). Another recent trend in science is hydrogen sulfide energy. Energy production from hydrogen sulfide deposits from the bottom of the Black Sea is being seriously studied.

The nature of the redox reactions of sulfur and hydrogen

The reaction of formation of hydrogen sulfide is redox:

H₂⁰ + S⁰→ H₂⁺S²⁻

The process of interaction of sulfur with hydrogen is easily explained by the structure of their atoms. Hydrogen ranks first in periodic system, therefore, its charge atomic nucleus is equal to (+1), and 1 electron is spinning around the nucleus of an atom. Hydrogen easily gives up its electron to the atoms of other elements, turning into a positively charged hydrogen ion - a proton:

H⁰ -1e⁻= H⁺

Sulfur is in the sixteenth position in the periodic table. Hence, the charge of the nucleus of its atom is (+16), and the number of electrons in each atom is also 16e⁻. The location of sulfur in the third period indicates that its sixteen electrons circle around the atomic nucleus, forming 3 layers, the last of which has 6 valence electrons. The number of valence electrons of sulfur corresponds to the number of group VI, in which it is located in the periodic system.

So, sulfur can donate all six valence electrons, as in the case of the formation of sulfur oxide (VI):

2S⁰ + 3O2⁰ → 2S⁺⁶O₃⁻²

In addition, as a result of the oxidation of sulfur, 4е⁻ can be given away by its atom to another element with the formation of sulfur oxide (IV):

S⁰ + O2⁰ → S⁺4 O2⁻²

Sulfur can also donate two electrons to form sulfur(II) chloride:

S⁰ + Cl2⁰ → S⁺² Cl2⁻

In all three of the above reactions, sulfur donates electrons. Consequently, it is oxidized, but at the same time acts as a reducing agent for oxygen atoms O and chlorine Cl. However, in the case of the formation of H2S, oxidation is the fate of hydrogen atoms, since it is they who lose electrons, restoring the external energy level of sulfur from six electrons to eight. As a result, each hydrogen atom in its molecule becomes a proton:

H2⁰-2e⁻ → 2H⁺,

and the sulfur molecule, on the contrary, being reduced, turns into a negatively charged anion (S⁻²): S⁰ + 2е⁻ → S⁻²

Thus, in chemical reaction sulfur is the oxidizing agent in the formation of hydrogen sulfide.

From the point of view of the manifestation of various oxidation states by sulfur, another interaction of sulfur oxide (IV) and hydrogen sulfide is also interesting - the reaction of obtaining free sulfur:

2H₂⁺S-²+ S⁺⁴О₂-²→ 2H₂⁺O-²+ 3S⁰

As can be seen from the reaction equation, both the oxidizing agent and the reducing agent in it are sulfur ions. Two sulfur anions (2-) donate two of their electrons to the sulfur atom in the sulfur oxide molecule (II), as a result of which all three sulfur atoms are reduced to free sulfur.

2S-² - 4е⁻→ 2S⁰ - reducing agent, oxidized;

S⁺⁴ + 4е⁻→ S⁰ - oxidant, is reduced.

When heated, sulfur reacts with hydrogen. A poisonous gas with a pungent odor is formed - hydrogen sulfide. In another way it is called hydrogen sulfide, hydrogen sulfide, dihydrosulfide.

Structure

Hydrogen sulfide is a binary compound of sulfur and hydrogen. The formula of hydrogen sulfide is H 2 S. The structure of the molecule is similar to the structure of the water molecule. However, sulfur forms with hydrogen not a hydrogen, but a covalent polar bond. This is due to the fact that, unlike the oxygen atom, the sulfur atom is larger in volume, has a lower electronegativity and a lower charge density.

Rice. 1. The structure of hydrogen sulfide.

Receipt

Hydrogen sulfide is rarely found in nature. In small concentrations, it is part of associated, natural, volcanic gases. Seas and oceans contain hydrogen sulfide at great depths. For example, hydrogen sulfide is found at a depth of 200 meters in the Black Sea. In addition, hydrogen sulfide is released during the decay of proteins containing sulfur.

In industry, it is obtained in several ways:

reaction of acids with sulfides:
FeS + 2HCl → FeCl 2 + H 2 S;
effect of water on aluminum sulfide:
Al 2 S 3 + 6H 2 O → 2Al (OH) 3 + 3H 2 S;
fusing sulfur with paraffin:
C 18 H 38 + 18S → 18H 2 S + 18C.

The purest gas is obtained by direct interaction of hydrogen and sulfur. The reaction proceeds at 600°C.

Physical properties

Dihydrosulfide is a colorless gas with a rotten egg odor and a sweetish taste. It is a poisonous substance, dangerous in high concentrations. Due to its molecular structure, hydrogen sulfide does not liquefy under normal conditions.

General physical properties hydrogen sulfide:

poorly soluble in water;
exhibits the properties of a superconductor at a temperature of -70°C and a pressure of 150 GPa;
flammable;
soluble in ethanol;
liquefies at -60.3°C;
turns into solid at -85.6°C;
melts at -86°C;
boils at -60°C;
decomposes into simple substances (sulfur and hydrogen) at 400°C.

Under normal conditions, you can prepare a solution of hydrogen sulfide (hydrogen sulfide water). However, hydrogen sulfide does not react with water. In air, the solution quickly oxidizes and becomes cloudy due to the release of sulfur. Hydrogen sulfide water exhibits weak acid properties.

Rice. 2. Hydrogen sulfide water.

Chemical properties

Hydrogen sulfide is a powerful reducing agent. Main Chemical properties substances are described in the table.

Reaction	Description	The equation
With oxygen	Burns in air with a blue flame to form sulfur dioxide. With a lack of oxygen, sulfur and water are formed	2H 2 S + 4O 2 → 2H 2 O + 2SO 2; 2H 2 S + O 2 → 2S + 2H 2 O
With oxidizers	Oxidizes to sulfur dioxide or sulfur	3H 2 S + 4HClO 3 → 3H 2 SO 4 + 4HCl; 2H 2 S + SO 2 → 2H 2 O + 3S; 2H 2 S + H 2 SO 3 → 3S + 3H 2 O
With alkalis	With an excess of alkali, medium salts are formed, with a ratio of 1: 1 - acidic	H 2 S + 2NaOH → Na 2 S + 2H 2 O; H 2 S + NaOH → NaHS + H 2 O
dissociations	Dissociates stepwise in solution	H 2 S ⇆ H + + HS – ; HS - ⇆ H + + S 2-
quality	The formation of a black precipitate - lead sulfide	H 2 S + Pb(NO 3) 2 → PbS↓ + 2HNO 3

Rice. 3. Combustion of hydrogen sulfide.

Hydrogen sulfide is a toxic gas, so its use is limited. Most of the produced hydrogen sulfide is used in industrial chemistry for the production of sulfur, sulfide, sulfuric acid.

What have we learned?

From the topic of the lesson, we learned about the structure, production and properties of hydrogen sulfide or hydrogen sulfide. It is a colorless gas with an unpleasant odor. It is a toxic substance. Forms hydrogen sulfide water without interacting with water. In reactions, it exhibits the properties of a reducing agent. Reacts with atmospheric oxygen, strong oxidizing agents (oxides, oxygen acids), with alkalis. Dissociates in solution in two stages. Hydrogen sulfide is used in the chemical industry for the manufacture of derivatives.

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Sulfur is one of the substances known to mankind from time immemorial. Even the ancient Greeks and Romans found various uses for it. Pieces of native sulfur were used to perform the rite of expelling evil spirits. So, according to legend, Odysseus, returning to his home after long wanderings, first of all ordered to fumigate it with sulfur. There are many references to this substance in the Bible.

In the Middle Ages, sulfur occupied an important place in the arsenal of alchemists. As they believed, all metals are composed of mercury and sulfur: the less sulfur, the more noble. Practical interest in this substance in Europe increased in the XIII-XIV centuries, after the advent of gunpowder and firearms. Italy was the main supplier of sulfur.

Nowadays, sulfur is used as a raw material for the production of sulfuric acid, gunpowder, rubber vulcanization, organic synthesis, and pest control. Agriculture. Sulfur powder is used in medicine as an external disinfectant.

The interaction of sulfur with simple substances

Sulfur reacts like oxidizer :

2Na + S = Na 2 S

how reducing agent :

The interaction of sulfur with complex substances

a) sulfur does not dissolve in water and is not even wetted by water;

b) how the reducing agent sulfur interacts with ( , ) when heated:

S + 2H 2 SO 4 \u003d 3SO 2 + 2H 2 O

S + 2HNO 3 = H 2 SO 4 + 2NO

S + 6HNO 3 \u003d H 2 SO 4 + 6NO 2 + 2H 2 O

c) showing the properties of both an oxidizing agent and a reducing agent, sulfur enters into disproportionation reactions (self-oxidation-self-recovery) with solutions when heated:

3S + 6NaOH \u003d 2Na 2 S + Na 2 SO 3 + 3H 2 O

Hydrogen sulfide and hydrosulphuric acid

a) H 2 S + CaO \u003d CaS + H 2 O

b) H 2 S + NaOH = NaHS + H 2 O

c) CuSO 4 + H 2 S \u003d CuS ↓ + H 2 SO 4

d) Ca + H 2 S \u003d CaS + H 2

A qualitative reaction to hydrosulfide acid and its soluble salts (i.e., to the sulfide ion S 2-) is their interaction with soluble salts. In this case, a black precipitate of lead (II) sulfide PbS is released:

Na 2 S + Pb (NO 3) 2 \u003d PbS ↓ + 2NaNO 3

Oxidative - restorative properties

In oxidative reducing reactions both gaseous hydrogen sulfide and hydrosulfide acid exhibit strong reducing properties, since the sulfur atom in H 2 S has lowest degree oxidation - 2, and therefore can only be oxidized. It oxidizes easily: