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Nurturing:

Create conditions for the moral and aesthetic education of students to the environment, the ability to work in pairs during self-analysis of control sections, tests.

Developing:

to develop the ability to work in an atmosphere of search, creativity, to give each student the opportunity to achieve success; the ability to give self-assessment of activities in the lesson;

General education:

organize the activities of students for assimilation:

• knowledge
: Chemical properties and methods for producing sulfur dioxide and sulfurous acid;
• skills
: write equations chemical reactions characterizing the chemical properties of sulfurous acid and its salts in ionic and redox form.

During the classes

I. Organizational moment.

II. Learning new material:

1. Structure:

SO 2 (sulfur dioxide, sulfur (IV) oxide), molecular formula

Structural formula

2. Physical Properties

1. A colorless gas with a pungent odor, poisonous.
2. Highly soluble in water (40 V SO 2 dissolves in 1 V H 2 O at N.O.)
3. Heavier than air, poisonous.

3. Receipt

1. In industry: sulphide roasting.

FeS 2 + O 2 → Fe 2 O 3 + SO 2

a) Draw up an electronic balance sheet (OVR).

2. In laboratory conditions: the interaction of sulfites with strong acids:

Na 2 SO 3 + 2HCl → 2NaCl + SO 2 + H 2 O

3. When oxidizing metals with concentrated sulfuric acid:

Cu + H 2 SO 4 (conc) → CuSO 4 + SO 2 + H 2 O

b) Compile an electronic balance (OVR) .

4. Chemical properties of SO 2

1. Interaction with water

When dissolved in water, a weak and unstable sulfurous acid H 2 SO 3 is formed (exists only in aqueous solution).

SO 2 + H 2 O ↔ H 2 SO 3

2. Interaction with alkalis:

Ba (OH) 2 + SO 2 → BaSO 3 ↓ (barium sulfite) + H 2 O

Ba (OH) 2 + 2SO 2 (excess) → Ba (HSO 3) 2 (barium hydrosulfite)

3. Interaction with basic oxides (salt is formed):

SO 2 + CaO \u003d CaSO 3

4. Oxidation reactions, SO 2 - reducing agent:

SO 2 + O 2 → SO 3 (catalyst - V 2 O 5)

c) Draw up an electronic balance (OVR)

SO 2 + Br 2 + H 2 O → H 2 SO 4 + HBr

d) Draw up an electronic balance (OVR)

SO 2 + KMnO 4 + H 2 O → K 2 SO 4 + MnSO 4 + H 2 SO 4

e) Compile an electronic balance sheet (OVR)

5. Recovery reactions, SO 2 - oxidizing agent

SO 2 + C → S + CO 2 (when heated)

f) Compile an electronic balance sheet (OVR)

SO 2 + H 2 S → S + H 2 O

g) Compile an electronic balance (OVR)

5. Chemical properties of H 2 SO 3

1. sulfurous acid dissociates in steps:

H 2 SO 3 ↔ H + + HSO 3 - (first step, hydrosulfite is formed - anion)

HSO 3 - ↔ H+ + SO 3 2- (second stage, sulfite anion is formed)

H 2 SO 3 forms two series of salts:

Medium (sulfites)

Acidic (hydrosulfites)

2. A solution of sulfurous acid H 2 SO 3 has reducing properties:

H 2 SO 3 + I 2 + H 2 O \u003d H 2 SO 4 + HI

h) Compile an electronic balance (OVR)

III. Self control.

Carry out the transformations according to the scheme:

S → H 2 S → SO 2 → Na 2 SO 3 → BaSO 3 → SO 2

Write the equations for ion exchange reactions in full and short ionic form.

The self-test answers are displayed on the screen.

IV. Reflection.

Answer the questions in the table “Questions to the student” (Appendix 1).

v. Homework(differentiated)

Make tasks highlighted in red:

Equations a, c, e, g - “3”

Equations a – e – “4”

Equations a – h – “5”

Appendix 1

Questions to the student

Date ___________________ Class ______________________

Try to remember exactly what you heard in the lesson and answer the questions:

No. p / p	Questions
1	What was the topic of the lesson?
2	What was your goal in the lesson?
3	What is the conclusion of the lesson?
4	How did your classmates work in class?
5	How did you work in class?
6	Do you think you will cope with the homework given in the lesson?

Sulfur compounds (1U). sulfurous acid

In tetrahalides SHal 4, oxohalides SOI Ial 2 and dioxide S0 2, sulfurous acid 1I 2 S0 3 sulfur exhibits an oxidation state of +4. In all these compounds, as well as in their corresponding anionic complexes, the sulfur atom has an undivided pair of electrons. Based on the number of a-bonding and non-bonding electronic nars, the shape of the molecules of these compounds changes from a distorted tetrahedron (SHal 4) to angular shape(S0 9) through the shape of a trigonal pyramid (SOHal 2 and SO3). S(IV) compounds have acidic properties, which manifests itself in reactions with water:

Sulfur oxide (1U) S0 2, or sulfur dioxide, is formed by burning sulfur in air or oxygen, as well as by calcining sulfides, such as pyrite:

The oxidation of pyrite underlies the industrial method for obtaining SO 2 . The S0 2 molecule is constructed similarly to the O e molecule and has the structure of an isosceles triangle with a sulfur atom at the top. Length S-O connections is 0.143 nm, and the bond angle is 119.5°:

The sulfur atom is in the 5/? 2 - hybridization. The p-orbital is oriented perpendicular to the plane of the molecule and does not participate in hybridization (Fig. 25.2). Due to this and other similarly oriented p-orbitals of oxygen atoms, a three-center n-bond is formed.

Rice. 25.2.

At normal conditions sulfur oxide (IV) is a colorless gas with a characteristic pungent odor. Let's well dissolve in water. Aqueous solutions are acidic, since S0 2, interacting with water, forms sulfurous acid H 2 S0 3. The reaction is reversible:

A characteristic feature of S0 2 is its redox duality. This is explained by the fact that in SO. ; sulfur has an oxidation state of +4, and therefore it can, giving up two electrons, be oxidized to S (VI), and receiving four electrons, be reduced to S. The manifestation of these and other properties depends on the nature of the reacting component. So, with strong oxidizing agents SO 2 behaves like a typical reducing agent. For example, halogens are reduced to the corresponding hydrogen halides, and S(IV) usually transforms into S(VI):

In the presence of strong reducing agents, S0 2 behaves like an oxidizing agent:

It is also characterized by a disproportionation reaction:

SQ, is an acidic oxide, readily soluble in water (1 volume of H 2 0 dissolves 40 volumes of S0 2). An aqueous solution of SO v is acidic and is called sulfurous acid. Usually, the bulk of the S0 2 dissolved in water is in solution in the hydrated form of S0 2 azH 2 0, and only a small part of S0 2 interacts with water according to the scheme

Sulfurous acid, as dibasic, forms two types of salts: medium - sulfites (Na 2 S0 3) and acidic - hydrosulfites (NaHS0 3). H 2 S0 3 exists in two tautomeric forms (Fig. 25.3).

Rice. 25.3.Structure of tautomeric forms H 2 S0 3

Since sulfur in sulfurous acid has an oxidation state of +4, it exhibits, like S0 2, the properties of both an oxidizing agent and a reducing agent, as already mentioned, therefore sulfurous acid completely duplicates the properties of S0 9 in oxidation-reduction reactions.

Salts of H 2 S0 3 (sulfites) have the properties of both oxidizing and reducing agents. So, the SO 2 ion easily passes into the SO 2 ion, showing strong reducing properties, therefore, in solutions, sulfites are gradually oxidized by molecular oxygen, turning into salts of sulfuric acid:

In the presence of strong reducing agents, sulfites behave like oxidizing agents. Under strong heating, the sulfites of the most active metals decompose at 600°C to form H2SO^ and H2S salts, i.e. disproportionation occurs.

Of the salts of sulfurous acid, only salts of the 5-elements of group I, as well as hydrosulfites of the Me 2+ (HS0 3) 2 type, are dissolved.

Since H 2 S0 3 is a weak acid, the action of acids on sulfites and hydrosulfites results in the release of S0 2, which is usually used to obtain S0 2 in the laboratory:

Water-soluble sulfites are easily hydrolyzed, resulting in an increase in the concentration of OH ions in the solution:

When S0 2 is passed through aqueous solutions of hydrosulfites, pyrosulfites are formed:

If a solution of Na 2 S0 3 is boiled with sulfur powder, then sodium thiosulfate is formed. In thiosulfates, sulfur atoms are in two different oxidation states - +6 and -2:

The resulting thiosulfate ion corresponds to the acid H 2 S 2 0 3, called thiosulfuric acid. Free acid is unstable under normal conditions and easily decomposes:

The properties of thiosulfates are due to the presence of and in them, moreover

the presence of S determines the reducing properties of the S 2 0 3 _ ion:

Weaker oxidizing agents oxidize sodium thiosulfate to salts of tetrathionic acid. An example is the interaction with iodine:

This reaction is widely used in analytical chemistry, as it is the basis of one of the essential methods volumetric analysis, called iodometry.

Alkali metal thiosulfates are produced commercially on a large scale. Among them highest value has sodium thiosulfate Na 2 S 2 0 3, which is used in medicine as an antidote for halogen and cyanide poisoning. The action of this drug is based on its ability to release sulfur, which, for example, with cyanide ions CN forms a less toxic rhodanide ion SCN:

The drug can also be used in case of poisoning with As, Pb, Hg compounds, since non-toxic sulfides are formed in this case. Na 2 S 2 0 3 is used when allergic diseases, arthritis, neuralgia. A characteristic reaction for Na 2 S 2 0 3 is its interaction with AgN0 3: a precipitate is formed white color Ag. ; S.; 0 3 , which over time under the influence of light and moisture turns black with the release of Ag 2 S:

These reactions are used for the qualitative detection of thiosulfate ion.

Thionyl chloride SOCl 2 is obtained by reacting S0 2 with PC1 5:

The SOCl 2 molecule has a pyramidal structure (Fig. 25.4). The bonds with sulfur are formed by a set of orbitals, which can be very roughly considered as $/? 3 - hybrid. One of them is occupied by a lone pair of electrons, so SOCl 2 can exhibit the properties of a weak Lyois base.

Rice. 25.4.

S () C1 2 - colorless fuming liquid with a pungent odor, hydrolyzes in the presence of traces of moisture:

Volatile compounds formed during the reaction are easily removed. Therefore, SOCl 2 is often used to obtain anhydrous chlorides:

SOCl 2 is widely used as a chlorinating agent in organic synthesis.

When sulfur dioxide (SO 2 ) is dissolved in water, a chemical compound known as sulfurous acid is obtained. The formula of this substance is written as follows: H 2 SO 3. In truth, this compound is extremely unstable, with a certain assumption, it can even be argued that it does not actually exist. Nevertheless, this formula is often used for the convenience of writing chemical reaction equations.

Sulfurous acid: basic properties

An aqueous solution of sulfur dioxide is characterized by an acidic environment. He himself has all the properties that are inherent in acids, including the neutralization reaction. Sulfurous acid is capable of forming two types of salts: hydrosulfites and ordinary sulfites. Both belong to the group of reducing agents. The first type is usually obtained when sulfurous acid is present in a fairly large amount: H 2 SO 3 + KOH -> KHSO 3 + H 2 O. Otherwise, ordinary sulfite is obtained: H 2 SO 3 + 2KOH -> K 2 SO 3 + 2H 2 O. A qualitative reaction to these salts is their interaction with a strong acid. As a result, SO 2 gas is released, which is easily distinguished by its characteristic pungent odor.

Sulfurous acid can have a bleaching effect. It is no secret that chlorine water also gives a similar effect. However, the compound in question has one important advantage: unlike chlorine, sulfurous acid does not lead to the destruction of dyes, sulfur dioxide forms colorless dyes with them. chemical compounds. This property often used for bleaching fabrics made of silk, wool, plant material, as well as everything that is destroyed by oxidizing agents containing Cl in its composition. In the old days, this compound was even used to restore the original look of ladies' straw hats. H 2 SO 3 is a fairly strong reducing agent. With the access of oxygen, its solutions gradually turn into sulfuric acid. In those cases when it interacts with a stronger reducing agent (for example, with hydrogen sulfide), sulfuric acid, on the contrary, exhibits oxidizing properties. Dissociation given substance takes place in two stages. First, the hydrosulfite anion is formed, and then the second step occurs, and it turns into the sulfite anion.

Where is sulfuric acid used?

The production of this substance plays an important role in the production of various wine materials as an antiseptic, in particular, with its help it is possible to prevent the fermentation process of the product in barrels and thereby ensure its safety. It is also used to prevent the fermentation of grain during the extraction of starch from it. Sulfurous acid and preparations based on it have a broad antimicrobial property, and therefore they are often used in the fruit and vegetable industry for canning. Calcium hydrosulfite, also called sulfite liquor, is used to process wood into sulfite pulp, from which paper is subsequently made. It remains to add that for a person this compound is poisonous, and therefore any laboratory works and experiments with it require caution and increased attention.

In redox processes, sulfur dioxide can be both an oxidizing agent and a reducing agent because the atom in this compound has an intermediate oxidation state of +4.

How does the oxidizing agent SO 2 react with stronger reducing agents, for example with:

SO 2 + 2H 2 S \u003d 3S ↓ + 2H 2 O

How does the reducing agent SO 2 react with stronger oxidizing agents, for example with in the presence of a catalyst, with, etc.:

2SO 2 + O 2 \u003d 2SO 3

SO 2 + Cl 2 + 2H 2 O \u003d H 2 SO 3 + 2HCl

Receipt

1) Sulfur dioxide is formed during the combustion of sulfur:

2) In industry, it is obtained by firing pyrite:

3) In the laboratory, sulfur dioxide can be obtained:

Cu + 2H 2 SO 4 \u003d CuSO 4 + SO 2 + 2H 2 O

Application

Sulfur dioxide is widely used in textile industry for bleaching various products. Moreover, it is used in agriculture for the destruction of harmful microorganisms in greenhouses and cellars. AT large quantities SO 2 is used to produce sulfuric acid.

Sulfur oxide (VI) – SO 3 (sulfuric anhydride)

Sulfuric anhydride SO 3 is a colorless liquid, which at temperatures below 17 ° C turns into a white crystalline mass. It absorbs moisture very well (hygroscopic).

Chemical properties

Acid-base properties

How typical acid oxide sulfuric anhydride interacts:

SO 3 + CaO = CaSO 4

c) with water:

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

A special property of SO 3 is its ability to dissolve well in sulfuric acid. A solution of SO 3 in sulfuric acid is called oleum.

Oleum formation: H 2 SO 4 + n SO 3 \u003d H 2 SO 4 ∙ n SO 3

redox properties

Sulfur oxide (VI) is characterized by strong oxidizing properties (usually reduced to SO 2):

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

Getting and using

Sulfuric anhydride is formed during the oxidation of sulfur dioxide:

2SO 2 + O 2 \u003d 2SO 3

Pure sulfuric anhydride practical value does not have. It is obtained as an intermediate in the production of sulfuric acid.

H2SO4

Mention of sulfuric acid is first found among Arab and European alchemists. It was obtained by calcining iron sulfate (FeSO 4 ∙ 7H 2 O) in air: 2FeSO 4 \u003d Fe 2 O 3 + SO 3 + SO 2 or a mixture with: 6KNO 3 + 5S \u003d 3K 2 SO 4 + 2SO 3 + 3N 2, and the emitted vapors of sulfuric anhydride were condensed. Absorbing moisture, they turned into oleum. Depending on the method of preparation, H 2 SO 4 was called vitriol oil or sulfur oil. In 1595, the alchemist Andreas Libavius ​​established the identity of both substances.

For a long time, vitriol oil did not find wide application. Interest in it greatly increased after the 18th century. Indigo carmine, a stable blue dye, was discovered. The first factory for the production of sulfuric acid was founded near London in 1736. The process was carried out in lead chambers, at the bottom of which water was poured. A molten mixture of saltpeter with sulfur was burned in the upper part of the chamber, then air was let in there. The procedure was repeated until an acid of the required concentration was formed at the bottom of the container.

In the 19th century the method was improved: instead of saltpeter, nitric acid was used (it gives when decomposed in the chamber). To return nitrous gases to the system, special towers were designed, which gave the name to the whole process - the tower process. Factories operating according to the tower method still exist today.

Sulfuric acid is a heavy oily liquid, colorless and odorless, hygroscopic; dissolves well in water. When concentrated sulfuric acid is dissolved in water, a large number of heat, so it must be carefully poured into water (and not vice versa!) And mix the solution.

A solution of sulfuric acid in water with an H2SO4 content of less than 70% is usually called dilute sulfuric acid, and a solution of more than 70% is called concentrated sulfuric acid.

Chemical properties

Acid-base properties

Dilute sulfuric acid reveals everything characteristic properties strong acids. She reacts:

H 2 SO 4 + NaOH \u003d Na 2 SO 4 + 2H 2 O

H 2 SO 4 + BaCl 2 \u003d BaSO 4 ↓ + 2HCl

The process of interaction of Ba 2+ ions with sulfate ions SO 4 2+ leads to the formation of a white insoluble precipitate BaSO 4 . This is qualitative reaction to sulfate ion.

Redox properties

In dilute H 2 SO 4 , H + ions are oxidizing agents, and in concentrated H 2 SO 4 sulfate ions are SO 4 2+ . SO 4 2+ ions are stronger oxidizing agents than H + ions (see diagram).

AT dilute sulfuric acid dissolve metals that are in the electrochemical series of voltages to hydrogen. In this case, metal sulfates are formed and released:

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

Metals that are in the electrochemical series of voltages after hydrogen do not react with dilute sulfuric acid:

Cu + H 2 SO 4 ≠

concentrated sulfuric acid is a strong oxidizing agent, especially when heated. It oxidizes many, and some organic substances.

When concentrated sulfuric acid interacts with metals that are in the electrochemical series of voltages after hydrogen (Cu, Ag, Hg), metal sulfates are formed, as well as the product of sulfuric acid reduction - SO 2.

Reaction of sulfuric acid with zinc

With more active metals (Zn, Al, Mg), concentrated sulfuric acid can be reduced to free. For example, when sulfuric acid interacts with, depending on the concentration of the acid, various products of sulfuric acid reduction can simultaneously form - SO 2, S, H 2 S:

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

3Zn + 4H 2 SO 4 = 3ZnSO 4 + S↓ + 4H 2 O

4Zn + 5H 2 SO 4 = 4ZnSO 4 + H 2 S + 4H 2 O

In the cold, concentrated sulfuric acid passivates some metals, for example, and therefore it is transported in iron tanks:

Fe + H 2 SO 4 ≠

Concentrated sulfuric acid oxidizes some non-metals (, etc.), recovering to sulfur oxide (IV) SO 2:

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

C + 2H 2 SO 4 \u003d 2SO 2 + CO 2 + 2H 2 O

Getting and using

In industry, sulfuric acid is obtained by contact. The acquisition process takes place in three stages:

1. Obtaining SO 2 by roasting pyrite:

4FeS 2 + 11O 2 = 2Fe 2 O 3 + 8SO 2

1. Oxidation of SO 2 to SO 3 in the presence of a catalyst - vanadium (V) oxide:

2SO 2 + O 2 \u003d 2SO 3

1. Dissolution of SO 3 in sulfuric acid:

H2SO4+ n SO 3 \u003d H 2 SO 4 ∙ n SO 3

The resulting oleum is transported in iron tanks. Sulfuric acid of the required concentration is obtained from oleum by pouring it into water. This can be expressed in a diagram:

H 2 SO 4 ∙ n SO 3 + H 2 O \u003d H 2 SO 4

Sulfuric acid finds a variety of uses in a variety of fields. National economy. It is used for drying gases, in the production of other acids, for the production of fertilizers, various dyes and medicines.

Salts of sulfuric acid

Most sulfates are highly soluble in water (slightly soluble CaSO 4 , even less PbSO 4 and practically insoluble BaSO 4). Some sulfates containing water of crystallization are called vitriol:

CuSO 4 ∙ 5H 2 O copper sulfate

FeSO 4 ∙ 7H 2 O ferrous sulfate

Salts of sulfuric acid have everything. Their relation to heating is special.

Sulfates of active metals ( , ) do not decompose even at 1000 ° C, while others (Cu, Al, Fe) - decompose upon slight heating into metal oxide and SO 3:

CuSO 4 \u003d CuO + SO 3

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sulfurous acid- unstable dibasic inorganic acid of medium strength. Corresponds to the oxidation state of sulfur +4. Chemical formula $\backslash mathsf(H\_2SO\_3)$.

Chemical properties

Acid medium strength:

$\backslash mathsf(H\_2SO\_3\; \backslash rightleftarrows\; H^+\; +\; HSO\_3^-)$ $\backslash mathsf(HSO\_3^-\; \backslash rightleftarrows\; H^+\; +\; SO\_3^(2-))$

Exists only in dilute aqueous solutions(not selected in the free state):

$\backslash mathsf(SO\_2+H\_2O\; \backslash rightleftarrows\; H\_2SO\_3\; \backslash rightleftarrows\; H^++HSO\_3^-\; \backslash rightleftarrows\; 2H^+\; +\; SO\_3^(2-))$

Solutions of H 2 SO 3 always have a pungent specific odor that is not chemically bound by water SO2.

$\backslash mathsf(H\_2SO\_3\; +\; NaOH\; \backslash longrightarrow\; NaHSO\_3\; +\; H\_2O)$ $\backslash mathsf(H\_2SO\_3\; +\; 2NaOH\; \backslash longrightarrow\; Na\_2SO\_3\; +\; 2H\_2O)$

Like sulfur dioxide, sulfurous acid and its salts are strong reducing agents:

$\backslash mathsf(H\_2SO\_3\; +\; Br\_2\; +\; H\_2O\; \backslash longrightarrow\; H\_2SO\_4\; +\; 2HBr)$

When interacting with even stronger reducing agents, it can play the role of an oxidizing agent:

$\backslash mathsf(H\_2SO\_3\; +\; 2H\_2S\; \backslash longrightarrow\; 3S\; \backslash downarrow\; +\; 3H\_2O)$

Qualitative reaction to sulfite ions - discoloration of a solution of potassium permanganate:

$\backslash mathsf(5SO\_3^(2-)\; +\; 6H^(+)\; +\; 2MnO\_4^(-)\; \backslash longrightarrow\; 5SO\_4^(2-)\; +\; 2Mn^(2+)\; +\; 3H\_2O)$

Application

Sulfuric acid and its salts are used as reducing agents, for bleaching wool, silk and other materials that cannot withstand bleaching with strong oxidants(chlorine). Sulfuric acid is used in the preservation of fruits and vegetables. Calcium hydrosulfite (sulfite liquor, Ca (HSO 3) 2) is used to process wood into the so-called sulfite cellulose (calcium hydrosulfite solution dissolves lignin, a substance that binds cellulose fibers, as a result of which the fibers are separated from each other; wood treated in this way is used for receiving paper).

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Literature

• Chemical Encyclopedia / Ed.: Knunyants I.L. and others. - M .: Soviet Encyclopedia, 1995. - V. 4 (Pol-Three). - 639 p. - ISBN 5-82270-092-4.

An excerpt characterizing sulfurous acid

- Now. - Are you ready, mom?
- Just pin the current.
“Don’t do it without me,” Natasha shouted: “you won’t be able to!”
- Yeah, ten.
It was decided to be at the ball at half past ten, and Natasha still had to get dressed and stop by the Tauride Garden.
Having finished her hair, Natasha, in a short skirt, from under which ballroom shoes were visible, and in her mother's blouse, ran up to Sonya, examined her and then ran to her mother. Turning her head, she pinned the current, and, barely having time to kiss her gray hair, she again ran to the girls who were hemming her skirt.
The case was behind Natasha's skirt, which was too long; it was hemmed by two girls, hastily biting the threads. A third, with pins in her lips and teeth, ran from the countess to Sonya; the fourth held the entire smoky dress on a high hand.
- Mavrusha, rather, dove!
- Give me a thimble from there, young lady.
– Will it be soon? - said the count, entering from behind the door. “Here are the spirits. Peronskaya was already waiting.
“It’s ready, young lady,” said the maid, lifting a hemmed smoky dress with two fingers and blowing and shaking something, expressing with this gesture the awareness of the airiness and purity of what she was holding.
Natasha began to put on a dress.
“Now, now, don’t go, dad,” she shouted to her father, who opened the door, still from under the haze of a skirt that covered her entire face. Sonya closed the door. A minute later, the count was let in. He was in a blue tailcoat, stockings and shoes, perfumed and pomaded.
- Oh, dad, you're so good, lovely! - said Natasha, standing in the middle of the room and straightening the folds of smoke.
“Excuse me, young lady, excuse me,” the girl said, kneeling, pulling at her dress and turning the pins from one side of her mouth to the other.
- Your will! - Sonya cried out with despair in her voice, looking at Natasha's dress, - your will, again long!
Natasha stepped aside to look around in the dressing-glass. The dress was long.
“By God, madam, nothing is long,” said Mavrusha, who was crawling along the floor after the young lady.
“Well, it’s a long time, so we’ll sweep it, we’ll sweep it in a minute,” said the resolute Dunyasha, taking out a needle from a handkerchief on her chest and again set to work on the floor.
At that moment, shyly, with quiet steps, the countess entered in her toque and velvet dress.
- Wow! my beauty! shouted the Count, “better than all of you!” He wanted to hug her, but she pulled away, blushing, so as not to cringe.
“Mom, more on the side of the current,” Natasha said. - I'll cut it, and rushed forward, and the girls who were hemming, who did not have time to rush after her, tore off a piece of smoke.
- My God! What is it? I don't blame her...
“Nothing, I notice, you won’t see anything,” said Dunyasha.
- Beauty, my darling! - said the nanny who came in from behind the door. - And Sonyushka, well, beauties! ...
At a quarter past eleven we finally got into the carriages and drove off. But still it was necessary to stop by the Tauride Garden.
Peronskaya was already ready. Despite her old age and ugliness, exactly the same thing happened with her as with the Rostovs, although not with such haste (for her it was a habitual thing), but she was also perfumed, washed, powdered old, ugly body, also diligently washed behind the ears, and even, and just like the Rostovs, the old maid enthusiastically admired her mistress's outfit when she went into the living room in a yellow dress with a cipher. Peronskaya praised the Rostovs' toilets.
The Rostovs praised her taste and dress, and, taking care of their hair and dresses, at eleven o'clock they got into the carriages and drove off.

Natasha had not had a moment of freedom since the morning of that day, and had never had time to think about what lay ahead of her.
In the damp, cold air, in the cramped and incomplete darkness of the swaying carriage, for the first time she vividly imagined what awaited her there, at the ball, in the illuminated halls - music, flowers, dances, sovereign, all the brilliant youth of St. Petersburg. What awaited her was so wonderful that she did not even believe that it would be: it was so inconsistent with the impression of cold, crowdedness and darkness of the carriage. She understood everything that awaited her only when, having walked along the red cloth of the entrance, she entered the hallway, took off her fur coat and walked beside Sonya in front of her mother between the flowers along the illuminated stairs. Only then did she remember how she had to behave at the ball and tried to assume that majestic manner, which she considered necessary for a girl at the ball. But fortunately for her, she felt that her eyes were running wide: she could not see anything clearly, her pulse beat a hundred times a minute, and the blood began to pound at her heart. She could not adopt that manner which would have made her ridiculous, and she walked, dying from excitement and trying with all her might only to hide it. And this was the very manner that most of all went to her. In front of them and behind them, talking in the same low voice and also in ball gowns, the guests entered. The mirrors on the stairs reflected ladies in white, blue, pink dresses, with diamonds and pearls on open hands and necks.