LABORATORY EXPERIMENTS ON THE TOPIC: “GENETIC RELATIONSHIP BETWEEN HYDROCARBONS, ALCOHOLS, ALDEHYDES AND ACIDS”

Saturated hydrocarbons

Of the saturated hydrocarbons, the school studies in detail methane as a substance that is the simplest in composition and structure, the most accessible for practical acquaintance and is of great economic importance as a chemical raw material and fuel.

Experiments with the first one studied in organic chemistry substance, must be supplied in sufficient quantities and with special care in methodological terms, since they must show new aspects of the experiment in the study of organic chemistry. Here it will be possible to establish experimentally the composition and molecular formula substances, which is the first step in determining the structural formulas organic compounds.

METHANE.

The order of experiments with methane may be different. Basically, it will be determined by whether the teacher will begin the topic by obtaining methane and then conduct experiments to study its properties, using the substance obtained in the lesson, or use pre-prepared methane in order to clearly follow the sequence of studying the questions - consider first physical properties substances, then Chemical properties, applying the substance and finally obtaining it. In the latter case, the experience of producing methane will be presented only at the end of the topic.

The first way of studying a topic and, therefore, constructing an experiment is more methodologically complex, but more time-saving. The second method will require more time, but it is methodologically simpler and is also valuable in that it will allow you to finally repeat and consolidate the knowledge of basic experiments with a substance when it is acquired in class.

When studying methane, there is no particular need for laboratory experiments. Essentially, they could be reduced here only to the production of methane and its combustion. But the production of methane from sodium acetate and its combustion can easily be demonstrated on a demonstration table.

It would be more advisable to conduct a special practical lesson after studying the entire topic “Hydrocarbons”. In this lesson, students will reproduce the experience of producing methane and will be able to verify that methane does not discolor bromine water and potassium permanganate solution.

Producing methane in the laboratory. The most convenient laboratory method for producing methane is the interaction of sodium acetate with soda lime.

The interaction of salts of carboxylic acids with alkali is in a general way obtaining hydrocarbons. Reaction in general view represented by the equation:

if R = CH 3, then methane is formed.

Since caustic soda is a hygroscopic substance, and the presence of moisture interferes successful completion reaction, then calcium oxide is added to it. A mixture of sodium hydroxide and calcium oxide is called soda lime.

For the reaction to proceed successfully, quite high heating is required, however, excessive overheating of the mixture leads to side processes and the production of undesirable products, such as acetone:

Sodium acetate must be dehydrated before the experiment. Soda lime should also be calcined before preparing the mixture. If there is no ready-made soda lime, it is prepared as follows. In an iron or porcelain cup, pour well-calcined crushed lime CaO with half the amount of a saturated aqueous solution of alkali NaOH. The mixture is evaporated to dryness, calcined and crushed. Substances are stored in a desiccator.

To demonstrate the production of methane, it is best to use a small flask with an outlet tube, and to practical lesson-- test tube (Fig. 1 and 2).

Assemble the device as shown in Fig. 1 or 2. An alkali solution is poured into a washing bottle to catch impurities (Fig. I). A mixture of sodium acetate and soda lime is placed in a reaction flask or test tube. To do this, finely ground substances are thoroughly mixed in a volume ratio of 1:3, i.e. with a significant excess of lime to force the sodium acetate to react as completely as possible.

Rice.

The flask is heated with a burner through an asbestos mesh, and the test tube is heated on a bare flame. Methane is collected in a test tube by displacing water. To check the purity of the resulting gas, remove the test tube from the water and ignite the gas without turning it over.

Since it is impractical to interrupt the process of producing methane, and it is impossible to complete all other experiments while the reaction is in progress, it is recommended to collect gas for subsequent experiments in several cylinders (test tubes) or in a gasometer.

The filled cylinders are left in the bath for a while or covered under water with a glass plate (stopper) and placed upside down on the table.

Methane is lighter than air. To familiarize yourself with the physical properties of methane, the teacher demonstrates a cylinder with collected gas. Students observe that methane is a colorless gas. The collection of methane by the method of displacing water suggests that this gas is apparently insoluble in water. The teacher confirms this conclusion.

Two identical flasks of the largest possible capacity are balanced on the scales. One of the flasks is hung upside down (Fig. 3). Methane from the device is passed into this flask for some time. The scales rise up. So that students do not think that the change in weight occurs due to the pressure of the gas stream on the bottom of the flask, pay attention to the fact that the imbalance remains even after the passage of methane has stopped.

After the scales are brought back into balance (to do this, turn the bottle with methane upside down for a while), for comparison and more convincing conclusions, methane is passed into a flask normally standing on the scales. The balance of the scales is not disturbed.

Having shown that methane is lighter than air, the teacher tells how much it weighs normal conditions liter of methane. This information will be needed later when deriving the molecular formula of a substance.

Methane combustion. Following consideration of the physical properties of methane, the question can be raised of what is the molecular formula of methane. The teacher reports that in order to clarify this issue, it will be necessary to first become familiar with one of the chemical properties of methane - combustion.

Methane combustion can be shown in two ways.

1. A glass cylinder (with a capacity of, for example, 250 ml) filled with methane is placed on the table, the plate is removed from it or the cork is opened and the gas is immediately ignited with a splinter. As methane burns, the flame descends into the cylinder.

In order for the flame to remain above the cylinder all the time and be clearly visible to students, water can be gradually poured into the cylinder with burning methane, thereby displacing the gas out (Fig. 4).

2. Methane is ignited directly at the outlet tube of the device to produce gas or a gas meter (in both cases, a check for purity is required!). The size of the flame is controlled by the heating intensity in the first case and the height of the column of displacing liquid in the second case. If methane is free of impurities, it burns with an almost colorless flame. To eliminate some of the flame luminosity (yellow color) caused by sodium salts in the glass of the tube, a metal tip can be attached to the end of the tube.

ALDEHYDES AND KETONES

When studying aldehydes, students become familiar with the stepwise nature of oxidation through experiments. organic matter, with the chemistry of important production processes and with the principle of obtaining synthetic resins.

To make the place of aldehydes in the series of hydrocarbon oxidation products clear to students, when drawing up chemical equations one should not avoid using the names and formulas of the acids into which aldehydes are converted. The formulas of acids can be given dogmatically in advance; In the future, students will receive experimental justification for them.

When studying aldehydes, most experiments are carried out with formaldehyde as a substance that is most accessible to schools and has great industrial importance. In accordance with this, formaldehyde is given a major place in this chapter. For acetaldehyde, only the preparation reactions are considered. Ketones are not specifically taught in school; therefore, only one representative of them is taken here - acetone, and experiments with it are given mainly for extracurricular activities students.

FORMALDEHYDE (METHANAL)

It is advisable to build a plan for studying this substance in such a way that immediately after becoming familiar with the physical properties of aldehydes, students study the methods of obtaining it, then the chemical properties, etc. Somewhat more early introduction with methods for producing aldehyde will make it possible further, when studying the chemical properties (oxidation reactions), to consider aldehydes as a link in the chain of oxidation of hydrocarbons.

When familiarizing yourself with the properties of formaldehyde, you can use formaldehyde as a sample. In this case, you should immediately ensure that students clearly understand the difference between formaldehyde and formaldehyde.

Formaldehyde smell. Of the physical properties of formaldehyde, the most accessible in practice is the smell. For this purpose, test tubes with 0.5-1 ml of formaldehyde are distributed to students. Once students are familiar with the smell, the formaldehyde can be collected and used for further experiments. Familiarization with the smell of formaldehyde will enable students to detect this substance in other experiments.

Flammability of formaldehyde. Heat formaldehyde in a test tube and ignite the released vapors; they burn with an almost colorless flame. The flame can be seen if you light a splinter or piece of paper in it. The experiment is carried out in a fume hood.

Obtaining formaldehyde. Since formaldehyde can only be detected by smell before becoming familiar with its chemical properties, the first experience of obtaining it should be carried out in the form of laboratory work.

1. A few drops of methanol are poured into a test tube. In the flame of the burner, a small piece of copper mesh or a spiral of copper wire rolled into a tube is heated and quickly lowered into methanol.

When calcined, copper oxidizes and becomes covered with a black coating of copper oxide; in alcohol it is again reduced and becomes red:

A pungent odor of aldehyde is detected. If the oxidation process is repeated 2-3 times, a significant concentration of formaldehyde can be obtained and the solution can be used for subsequent experiments.

2. In addition to copper oxide, other oxidizing agents familiar to students can be used to produce formaldehyde.

0.5 ml of methanol is added to a weak solution of potassium permanganate in a demonstration tube and the mixture is heated to boiling. The smell of formaldehyde appears, and the purple color of the permanganate disappears.

2-3 ml of a saturated solution of potassium dichromate K 2 Cr 2 O 7 and the same volume of concentrated sulfuric acid are poured into a test tube. Add methanol drop by drop and very carefully heat the mixture (the hole of the test tube is directed to the side!). The reaction then proceeds with the release of heat. The yellow color of the chromium mixture disappears, and the green color of chromium sulfate appears

The reaction equation does not need to be discussed with students. As in the previous case, they are only informed that potassium dichromate oxidizes methyl alcohol into an aldehyde, thereby turning into the trivalent chromium salt Cr 2 (SO 4) 3.

Reaction of formaldehyde with silver oxide(silver mirror reaction). This experience must be demonstrated to students in such a way that it simultaneously serves as instruction for the subsequent practical lesson.

Preparation of phenol-formaldehyde resins. The bulk of formaldehyde produced in industry is used for the synthesis of phenol-formaldehyde and other resins necessary for the production of plastics. The production of phenol-formaldehyde resins is based on the polycondensation reaction.

The synthesis of phenol-formaldehyde resin is most accessible in school conditions. Students by this time are already familiar with both initial substances for producing resin - phenol and formaldehyde; the experiment is relatively simple and goes smoothly; the chemistry of the process does not present any particular difficulty for students if it is depicted as follows:

Depending on the quantitative ratio of phenol and formaldehyde, as well as on the catalyst used (acidic or alkaline), novolac or resol resin can be obtained. The first of them is thermoplastic and has the linear structure shown above. The second is thermoreactive, since its linear molecules contain free alcohol groups - CH 2 OH, which can react with mobile hydrogen atoms of other molecules, resulting in the formation of a three-dimensional structure.

ACETALDEHYDE (ETHANAL)

After a detailed review of the properties of formaldehyde in this section of the topic highest value acquire experiments related to the production of acetaldehyde. These experiments can be carried out with the aim of: a) showing that all aldehydes can be obtained by oxidation of the corresponding monohydric alcohols, b) showing how the structure of aldehydes can be experimentally substantiated, c) introducing the chemistry of the industrial method for producing acetaldehyde according to Kuchsrov.

Preparation of acetaldehyde by oxidation of ethanol. Copper (II) oxide can be taken as an oxidizing agent for alcohol. The reaction proceeds similarly to the oxidation of methanol:

• 1. No more than 0.5 ml of ethyl alcohol is poured into a test tube and a hot copper wire is immersed. A fruit-like odor of acetaldehyde is detected and copper reduction is observed. If the oxidation of alcohol is carried out 2-3 times, each time heating the copper until copper oxide is formed, then, having collected the solutions obtained by the students in test tubes, it will be possible to use the aldehyde for experiments with it.
• 2. Place 5 g of crushed potassium dichromate K2Cr2O7 into a small flask with an outlet tube, pour in 20 ml of diluted sulfuric acid (1:5) and then 4 ml of ethyl alcohol. A refrigerator is connected to the flask and heated over a small flame through an asbestos mesh. The distillate receiver is placed in ice water or snow. A little water is poured into the receiver and the end of the refrigerator is lowered into the water. This is done in order to reduce the volatilization of acetaldehyde vapors (boiling point 21 ° C). Together with ethanal, a certain amount of water and unreacted alcohol formed is distilled into the receiver. acetic acid and other reaction by-products. However, there is no need to isolate pure acetaldehyde, since the resulting product reacts well with ordinary aldehyde reactions. The presence of aldehyde is determined by smell and by the reaction of a silver mirror.

Students' attention is drawn to the change in color in the flask. The green color of the resulting chromium (III) sulfate Cr 2 (SO 4) 3 becomes especially distinct if the contents of the flask are diluted with water after the experiment. It is noted that the change in color of potassium bichromate occurred due to its oxidation of alcohol.

Preparation of acetaldehyde by hydration of acetylene. The remarkable discovery of the Russian chemist M.G. Kucherov - the addition of water to acetylene in the presence of mercury salts formed the basis for a widespread industrial method for producing acetaldehyde.

Despite great importance and accessibility for school, this method is rarely demonstrated in chemistry lessons.

In industry, the process is carried out by passing acetylene into water containing divalent mercury salts and sulfuric acid at a temperature of 70°C. The resulting acetaldehyde under these conditions is distilled off and condensed, after which it enters special towers for oxidation into acetic acid. Acetylene is obtained from calcium carbide in the usual way and purified from impurities.

The need to purify acetylene and maintain the temperature in the reaction vessel, on the one hand, and the uncertainty of obtaining the desired product, on the other, usually reduce interest in this experiment. Meanwhile, the experiment can be carried out quite simply and reliably both in a simplified form and in conditions approaching industrial ones.

1. An experiment that to a certain extent reflects the reaction conditions in production and makes it possible to obtain a sufficiently concentrated aldehyde solution can be carried out in the device shown in Fig. 29.

The first stage is the production of acetylene. Pieces of calcium carbide are placed in the flask and water or a saturated solution of table salt is slowly added from a dropping funnel. The pinning speed is adjusted so that a smooth flow of acetylene is established, approximately one bubble per 1-2 s. Acetylene is purified in a washing machine with a solution of copper sulfate:

CuSO 4 + H 2 S H 2 SO 4

After purification, the gas is passed into a flask with a catalyst solution (15-20 ml of water, 6-7 ml of concentrated sulfuric acid and about 0.5 g of mercury (II) oxide. The flask, where acetylene hydration takes place, is heated with a burner (alcohol lamp) , and the resulting acetaldehyde in gaseous form enters test tubes with water, where it is absorbed.

After 5-7 minutes in a test tube it is possible to obtain a solution of ethanal of significant concentration. To complete the experiment, first stop the supply of water to the calcium carbide, then disconnect the device and, without any additional distillation of the aldehyde from the reaction flask, use the resulting solutions in test tubes for the corresponding experiments.

2. In its most simplified form, M.G. Kucherov’s reaction can be carried out as follows.

Pour 30 ml of water and 15 ml of conc. into a small round-bottomed flask. sulfuric acid. The mixture is cooled and a little mercury (II) oxide is added to it (at the tip of a spatula). Heat the mixture carefully through an asbestos mesh until it boils, and the mercury oxide turns into mercury (II) sulfate.

Option 1

1. Write the reaction equations that can be used to carry out the following transformations: methane → chlorine-methane → methanol → formaldehyde → formic acid. Specify the reaction conditions.

2. Write the structural formula of a substance with the composition C₃H₆O₂, if it is known that it water solution changes the color of methyl orange to red; with chlorine this substance forms the compound C₃H₅ClO₂, and when heated sodium salt Ethane is formed with sodium hydroxide. Name the substance.

3. Calculate the mass of the substance (in grams) and the amount of substance (in moles) of each product when carrying out the following transformations: bromoethane → ethanol → ethanoic acid. Bromoethane was taken with a mass of 218 g.

Option 2

1. Write the reaction equations that can be used to carry out the following transformations: acetylene → ethylene → ethanol → acetaldehyde → acetic acid. Specify the reaction conditions.

2. Write the structural formula of a substance with the composition C₄H₈O, if it is known that it reacts with copper (II) hydroxide and upon oxidation forms 2-methylpropanoic acid. Name this substance.

3. Calculate the mass of the substance (in grams) and the amount of substance (in moles) of each product during the following transformations: propane → 2-chloropropane → 2-propanol. Propane was taken with a mass of 22 g.

Option 3

1. Write the reaction equations that can be used to carry out the following transformations: methane → acetylene → acetaldehyde → ethyl alcohol → ethanoic acid. Specify the reaction conditions.

2. Write the structural formula of a substance with the composition C₅H₁₀O, if it is known that it adds hydrogen in the presence of a catalyst, and when heated with freshly prepared copper (II) hydroxide, it forms a red precipitate. Name this substance.

3. Calculate the mass of the substance (in grams) and the amount of substance (in moles) of each product during the following transformations: benzene → chlorobenzene → phenol. Benzene was taken with a mass of 156 g.

Option 4

1. Write the reaction equations that can be used to carry out the following transformations: methane → formaldehyde → methanol → formic acid → carbonic acid. Specify the reaction conditions.

2. Write the structural formula of a substance with the composition C₂H₆O₂, if it is known that it reacts with sodium to release hydrogen, and with copper (II) hydroxide it forms a bright blue substance. Name this substance.

3. Calculate the mass of the substance (in grams) and the amount of substance (in moles) of each product when carrying out the following transformations: chloromethane → methanol → methanoic acid. Chloromethane was taken with a mass of 202 g.

Tazhibaeva Asemgul Isintaevna

Teacher at Kamennobrod Secondary School

Chemistry lesson in 11th grade

Lesson topic: Genetic connection between hydrocarbons, alcohols, aldehydes, alcohols, carboxylic acids.

Lesson type: lesson of generalization of knowledge.

Lesson objectives: consolidate, generalize and systematize knowledge on oxygen-containing organic compounds, including on the basis of genetic connections between classes of these substances. Strengthen the ability to predict the chemical properties of unfamiliar organic substances, based on knowledge functional groups. To develop in students demonstrative speech, the ability to use chemical terminology, conduct, observe and describe a chemical experiment. To cultivate the need for knowledge about the substances with which we come into contact in life.

Methods: verbal, visual, practical, problem-search, knowledge control.

Reagents: acetylsalicylic acid(aspirin), water, iron(III) chloride, glucose solution, universal indicator, copper(II) sulfate solution, sodium hydroxide solution, egg white, ethanol, 1-butanol, acetic acid, stearic acid.

Equipment: computer, screen, projector, table “Classification of oxygen-containing organic substances”, supporting note “Functional group determines the properties of a substance”, mortar and pestle, glass rod, alcohol lamp, test tube holder, funnel, filter, glasses, rack with test tubes, pipette, graduated cylinder on 10 ml.

I. Organizational moment.

Today in class:

1) You will strengthen the ability to predict the chemical properties of unfamiliar organic substances based on knowledge of functional groups.

2) You will find out what functional groups you know are included in the most famous antipyretic drug.

3) You will find functional groups in a substance with a sweet taste, which is used in medicine as nutrient and a component of blood replacement fluids.

4) You will see how you can get pure silver.

5) We'll talk about physiological effects ethyl alcohol.

6) We will discuss the consequences of drinking alcoholic beverages by pregnant women.

7) You will be pleasantly surprised: it turns out that you already know so much!

II. Repetition and generalization of students' acquired knowledge.

1. Classification of oxygen-containing organic compounds.

We begin the generalization of the material with the classification of oxygen-containing organic substances. To do this, we will use the table “Classification of oxygen-containing organic compounds”. During frontal work, we will repeat oxygen-containing functional groups.

In organic chemistry, there are three most important functional groups, including oxygen atoms:hydroxyl, carbonyl Andcarboxyl. The latter can be considered as a combination of the previous two. Depending on which atoms or groups of atoms these functional groups are associated with, oxygen-containing substances are divided into alcohols, phenols, aldehydes, ketones and carboxylic acids.

Let's consider these functional groups and their effect on the physical and chemical properties of substances.

Viewing a video clip.

You already know that this is not the only thing possible sign classifications. There can be several identical functional groups in a molecule, and pay attention to the corresponding row of the table.

The next line reflects the classification of substances by the type of radical associated with the functional group. I would like to draw attention to the fact that, unlike alcohols, aldehydes, ketones and carboxylic acids, hydroxyarenes are classified into a separate class of compounds - phenols.

The number of functional groups and the structure of the radical determine the general molecular formula of the substances. In this table they are given only for the limiting representatives of classes with one functional group.

All classes of compounds that “fit” in the table aremonofunctional, i.e., they have only one oxygen-containing function.

To consolidate the material on the classification and nomenclature of oxygen-containing substances, I give several formulas of compounds and ask students to determine “their place” in the given classification and give a name.

formula

Name	Substance class
	Propinic acid	Unsaturated, monobasic acid
	Butanediol-1,4	Limit, dihydric alcohol
	1,3-Dihydroxybenzene	Diatomic phenol
	3-Methylbutanal	Saturated aldehyde
	Butene-3-one-2	Unsaturated ketone
	2-Methylbutanol-2	Limit, monohydric alcohol

Relationship between the structure and properties of oxygen-containing compounds.

The nature of the functional group has a significant impact on the physical properties of substances of this class and largely determines its chemical properties.

The concept of “physical properties” includes the state of aggregation of substances.

Aggregate state of linear connections of different classes:

Number of atoms C in a molecule

Alcohols	Aldehydes	Carboxylic acids
1	and.	G.	and.
2	and.	and.	and.
3	and.	and.	and.
4	and.	and.	and.
5	and.	and.	and.

The homologous series of aldehydes begins with a gaseous substance at room temperature - formaldehyde, and there are no gases among monohydric alcohols and carboxylic acids. What is this connected with?

Molecules of alcohols and acids are additionally connected to each other by hydrogen bonds.

The teacher asks students to formulate the definition of “hydrogen bond”(this is an intermolecular bond between the oxygen of one molecule and the hydroxyl hydrogen of another molecule) , corrects it and, if necessary, dictates for writing: a chemical bond between an electron-deficient hydrogen atom and an electron-rich atom of an element with high electronegativity (F , O , N ) is calledhydrogen.

Now compare the boiling points (°C) of the first five homologs of substances of three classes.

Number of atoms C in a molecule

Alcohols	Aldehydes	Carboxylic acids
1	+64,7	-19	+101
2	+78,3	+21	+118
3	+97,2	+50	+141
4	+117,7	+75	+163
5	+137,8	+120	+186

What can you say after looking at the tables?

In the homologous series of alcohols and carboxylic acids there are no gaseous substances and the boiling points of the substances are high. This is due to the presence of hydrogen bonds between molecules. Due to hydrogen bonds, molecules become associated (as if cross-linked), therefore, in order for the molecules to become free and acquire volatility, it is necessary to expend additional energy to break these bonds.

What can be said about the solubility of alcohols, aldehydes and carboxylic acids in water? (Demonstration of the solubility in water of alcohols - ethyl, propyl, butyl and acids - formic, acetic, propionic, butyric and stearic. A solution of formic aldehyde in water is also demonstrated.)

When answering, the scheme of formation of hydrogen bonds between molecules of acid and water, alcohols, and acids is used.

It should be noted that with increasing molecular weight, the solubility of alcohols and acids in water decreases. The larger the hydrocarbon radical in an alcohol or acid molecule, the more difficult it is for the OH group to keep the molecule in solution due to the formation of weak hydrogen bonds.

3. Genetic relationship between different classes of oxygen-containing compounds.

I draw on the board the formulas of a number of compounds containing one carbon atom:

CH 4 →CH 3 OH → HCOH → HCOOH→ CO 2

Why are they studied in this order in the organic chemistry course?

How does the oxidation state of a carbon atom change?

Students dictate the line: -4, -2, 0, +2, +4

It now becomes clear that each subsequent compound is an increasingly oxidized form of the previous one. From here it is obvious that one should move along the genetic series from left to right using oxidation reactions, and in the opposite direction using reduction processes.

Do ketones fall out of this “circle of relatives”? Of course not. Their predecessors are secondary alcohols.

The chemical properties of each class of substances were discussed in detail in the corresponding lessons. To summarize this material, I proposed as homework tasks on mutual transformations in a somewhat unusual form.

1. Compound with molecular formulaC 3 H 8 O subjected to dehydrogenation, resulting in a product with the compositionC 3 H 6 O . This substance undergoes a “silver mirror” reaction, forming the compoundC 3 H 6 O 2 . By treating the latter substance with calcium hydroxide, a substance was obtained that was used as food additives under code E 282. It prevents the growth of mold in baked goods and confectionery products and is also found in foods such as Swiss cheese. Determine the formula of the additive E 282, write the equations for the reactions mentioned and name all the organic substances.

Solution :

CH 3 –CH 2 –CH 2 –OH → CH 3 –CH 2 – COH + H 2 ( cat. – Cu, 200-300 °C)

CH 3 –CH 2 – COH + Ag 2 O → CH 3 –CH 2 – COOH + 2Ag (simplified equation, ammonia solution of silver oxide)

2CH 3 –CH 2 –COOH+WITHa(OH) 2 → (CH 3 –CH 2 – COO) 2 Ca+2H 2 O.

Answer: calcium propionate.

2. Composition compoundC 4 H 8 Cl 2 with a straight carbon skeleton heated with an aqueous solutionNaOH and obtained an organic substance, which, upon oxidationCu(OH) 2 turned intoC 4 H 8 O 2 . Determine the structure of the original compound.

Solution: if 2 chlorine atoms are located at different carbon atoms, then when treated with alkali we would get a dihydric alcohol that would not oxidizeCu(OH) 2 . If 2 chlorine atoms were located at one carbon atom in the middle of the chain, then when treated with alkali, a ketone would be obtained, which does not oxidizeCu(OH) 2. Then, the desired connection is1,1-dichlorobutane.

CH 3 –CH 2 –CH 2 – CHCl 2 + 2NaOH → CH 3 –CH 2 –CH 2 – COH + 2NaCl + H 2 O

CH 3 –CH 2 –CH 2 – COH + 2Cu(OH) 2 →CH 3 –CH 2 –CH 2 – COOH + Cu 2 O+2H 2 O

3. When 19.2 g of sodium salt of saturated monobasic acid was heated with sodium hydroxide, 21.2 g of sodium carbonate was formed. Name the acid.

Solution:

When heated, decarboxylation occurs:

R-COONa + NaOH → RH + Na 2 CO 3

υ (Na 2 CO 3 ) = 21,2 / 106 = 0,2 mole

υ (R-COONa) = 0.2mole

M(R-COONa) = 19.2 / 0.2 = 96G/ mole

M(R-COOH) =M(R-COONa) –M(Na) + M(H) = 96-23+1= 74G/ mole

In accordance with general formula of saturated monobasic carboxylic acids, to determine the number of carbon atoms, it is necessary to solve the equation:

12n + 2n + 32= 74

n=3

Answer: propionic acid.

To consolidate knowledge about the chemical properties of oxygen-containing organic substances, we will perform a test.

1 option

The following formulas correspond to saturated monohydric alcohols:
A) CH 2 O
B) C 4 H 10 O
IN) C 2 H 6 O
G) CH 4 O
D) C 2 H 4 O 2

It contains a combination of two principles,
One is in the birth of mirrors.
Of course, not for contemplation,
And for the science of understanding.
...And in the kingdom of the forest she is found,
The little brothers are her friends here,
Their hearts are given to them completely...

options:
A) picric acid
B) formic acid
B) acetic acid
D) carboxyl group
D) benzoic acid

Ethanol reacts with substances:
A) NaOH
B) Na
IN) HCl
G) CH 3 COOH
D) FeCl 3

A qualitative reaction to phenols is a reaction with
A) NaOH
B) Cu(OH) 2
IN) CuO
G) FeCl 3
D) HNO 3

Ethanal reacts with substances
A) methanol
B) hydrogen
B) ammonia solution of silver oxide
D) copper (II) hydroxide
D) hydrogen chloride

Option 2

Aldehydes can be obtained
A) oxidation of alkenes
B) oxidation of alcohols
B) hydration of alkynes
D) when heating calcium salts of carboxylic acids
D) hydration of alkenes

The functional group of alcohols is
A) COH
B) OH
IN) COOH
G) N.H. 2
D) NO 2

2-methylbutanol-2
A) unsaturated alcohol
B) limiting alcohol
B) monohydric alcohol
D) tertiary alcohol
D) aldehyde

Did you observe the reaction?
A) for polyhydric alcohols
B) alcohol oxidation
B) interaction of phenol with iron (III) chloride
D) “silver mirror”
D) “copper mirror”

Acetic acid reacts with substances
A) hydrogen
B) chlorine
B) propanol
D) sodium hydroxide
D) metanalem

Students fill out their answers in the table:

1, 2 var.

A	b	V	G	d
1		+	+	+
2		+
3		+	+	+
4				+
5		+	+	+

If you connect the correct answers with a solid line, you get the number “5”.

Group work of students.

Assignment for group 1

Goals:

Reagents and equipment: acetylsalicylic acid (aspirin), water, iron(III) chloride; mortar and pestle, glass rod, alcohol lamp, test tube holder, funnel, filter, glasses, rack with test tubes, pipette, 10 ml graduated cylinder.

Experiment 1. Evidence of the absence of phenolic hydroxyl in acetylsalicylic acid (aspirin).

2-3 grains of acetyl are placed in a test tube salicylic acid, add 1 ml of water and shake vigorously. Add 1-2 drops of iron(III) chloride solution to the resulting solution. What are you observing? Draw conclusions.

No purple color appears. Therefore, in acetylsalicylic acidNOOS-S 6 N 4 -O-CO-CH 3 there is no free phenolic group, since this substance is an ester formed by acetic and salicylic acids.

Experiment 2. Hydrolysis of acetylsalicylic acid.

A crushed acetylsalicylic acid tablet is placed in a test tube and 10 ml of water is added. Bring the contents of the test tube to a boil and boil for 0.5-1 minutes. Filter the solution. Then 1-2 drops of iron(III) chloride solution are added to the resulting filtrate. What are you observing? Draw conclusions.

Write down the reaction equation:

Complete the work by filling out a table that contains the following columns: operation performed, reagent, observations, conclusion.

A purple color appears, indicating the release of salicylic acid containing a free phenolic group. As an ester, acetylsalicylic acid is easily hydrolyzed when boiled with water.

Assignment for group 2

1. Consider the structural formulas of substances, name the functional groups.

2. Do lab work"Detection of functional groups in the glucose molecule".

Goals: consolidate students' knowledge of qualitative reactions of organic compounds, develop skills in experimental determination of functional groups.

Reagents and equipment: solution glucose, universal indicator, copper (II) sulfate solution, sodium hydroxide solution, alcohol lamp, test tube holder, matches, 10 ml graduated cylinder.

2.1. Pour 2 ml of glucose solution into a test tube. Using a universal indicator, draw a conclusion about the presence or absence of a carboxyl group.

2.2. Prepare copper (II) hydroxide: pour 1 ml of copper (II) sulfate into a test tube and add sodium hydroxide to it. Add 1 ml of glucose to the resulting precipitate and shake. What are you observing? What functional groups is it typical for? this reaction?

2.3. Heat the mixture obtained in experiment No. 2. Note the changes. What functional group is this reaction typical for?

2.4. Complete the work by filling out a table that contains the following columns: operation performed, reagent, observations, conclusion.

Demonstration experience. Interaction of glucose solution with ammonia solution of silver oxide.

Work results:

- there is no carboxyl group, because the solution has a neutral reaction to the indicator;

- the precipitate of copper (II) hydroxide dissolves and a bright blue color appears, characteristic of polyhydric alcohols;

- when this solution is heated, a yellow precipitate of copper (I) hydroxide precipitates, which turns red upon further heating, indicating the presence of an aldehyde group.

Conclusion. Thus, the glucose molecule contains carbonyl and several hydroxyl groups and is an aldehyde alcohol.

Assignment for group 3

Physiological effect of ethanol

1. What is the effect of ethanol on living organisms?

2. Using the equipment and reagents available on the table, demonstrate the effect of ethanol on living organisms. Comment on what you see.

Purpose of the experience: convince students that alcohol denatures proteins and irreversibly disrupts their structure and properties.

Equipment and reagents: rack with test tubes, pipette, 10 ml graduated cylinder, egg white, ethanol, water.

Progress of the experiment: Pour 2 ml of egg white into 2 test tubes. Add 8 ml of water to one, and the same amount of ethanol to the other.

In the first test tube, the protein dissolves and is well absorbed by the body. In the second test tube, a dense white precipitate forms - proteins do not dissolve in alcohol, alcohol takes away water from proteins. As a result, the structure and properties of the protein and its functions are disrupted.

3. Tell us about the effect of ethyl alcohol on various organs and human organ systems.

Explain the consequences of drinking alcohol to pregnant women.

Student performances.

Since ancient times, man has known a large number of toxic substances, all of which differ in the strength of their effect on the body. Among them stands out a substance that is known in medicine as a strong protoplasmic poison - ethyl alcohol. Mortality from alcoholism exceeds the number of deaths caused by all infectious diseases taken together.

Burning the mucous membrane of the oral cavity, pharynx, esophagus, it enters gastrointestinal tract. Unlike many other substances, alcohol is quickly and completely absorbed in the stomach. Easily crossing biological membranes, after about an hour it reaches its maximum concentration in the blood.

Alcohol molecules quickly penetrate biological membranes into the blood compared to water molecules. Ethyl alcohol molecules can easily cross biological membranes due to their small size, weak polarization, the formation of hydrogen bonds with water molecules, and the good solubility of alcohol in fats.

Quickly absorbed into the blood and dissolving well in the intercellular fluid, alcohol enters all cells of the body. Scientists have found that, by disrupting the functions of cells, it causes their death: when drinking 100 g of beer, about 3000 brain cells die, 100 g of wine - 500, 100 g of vodka - 7500, contact of red blood cells with alcohol molecules leads to the coagulation of blood cells.

The liver neutralizes toxic substances that enter the blood. Doctors call this organ a target for alcohol, since 90% of ethanol is neutralized in it. Occur in the liver chemical processes oxidation of ethyl alcohol.

We recall with students the stages of the alcohol oxidation process:

Ethyl alcohol is oxidized to final decomposition products only if the daily consumption of ethanol does not exceed 20 g. If the dose is exceeded, then intermediate decomposition products accumulate in the body.

This leads to a number of negative side effects: increased formation of fat and its accumulation in liver cells; accumulation of peroxide compounds that can destroy cell membranes, as a result of which the contents of the cells flow out through the formed pores; very undesirable phenomena, the combination of which leads to liver destruction - cirrhosis.

Acetaldehyde is 30 times more toxic than ethyl alcohol. In addition, as a result of various bio chemical reactions in tissues and organs, including the brain, the formation of tetrahydropapaveroline is possible, the structure and properties of which resemble well-known psychotropic drugs - morphine and cannabinol. Doctors have proven that it is acetaldehyde that causes mutations and various deformities in embryos.

Acetic acid enhances synthesis fatty acids and leads to fatty degeneration of the liver.

While studying the physical properties of alcohols, we addressed the issue of changes in their toxicity in the homologous series of monohydric alcohols. As the molecular weight of substance molecules increases, their narcotic properties increase. If we compare ethyl and pentyl alcohols, the molecular weight of the latter is 2 times greater, and its toxicity is 20 times greater. Alcohols containing three to five carbon atoms form so-called fusel oils, the presence of which in alcoholic beverages increases their toxic properties.

In this series, the exception is methanol - the strongest poison. When 1-2 teaspoons enter the body, it is affected optic nerve, which leads to complete blindness, and consumption of 30-100 ml leads to fatal outcome. The danger is heightened by the similarities methyl alcohol With ethyl alcohol by properties, appearance, smell.

Together with the students, we try to find the cause of this phenomenon. They put forward various hypotheses. We dwell on the fact that the factors that increase the toxicity of methyl alcohol include the small size of the molecules ( high speed distribution), as well as the fact that the intermediate products of its oxidation - formic aldehyde and formic acid - are strong poisons.

Alcohol that is not neutralized by the liver and the toxic products of its breakdown re-enter the bloodstream and are distributed throughout the body, remaining in it for a long time. For example, alcohol is found unchanged in the brain 20 days after taking it.

We draw students' attention to how alcohol and its breakdown products are eliminated from the body.

C 2 H 5 OH

	10% unchanged via lungs, kidneys and skin
		90% in the form CO 2 And N 2 ABOUT through the lungs and kidneys

Unfortunately, in Lately Alcohol consumption, like smoking, is common among women. The influence of alcohol on offspring goes in two directions.

Firstly, alcohol consumption is accompanied by profound changes in the sexual sphere of both men and women. Alcohol and its decomposition products can affect both female and male reproductive cells even before fertilization - their genetic information changes (see Fig. “Healthy (1) and pathological (2) sperm”).

If alcohol consumption is prolonged, the activity of the reproductive system is disrupted, it begins to produce defective germ cells.

Secondly, alcohol directly affects the embryo. Constant consumption of 75-80 g of vodka, cognac or 120-150 g of weaker alcoholic drinks (beer) can cause fetal alcohol syndrome. Through the placenta, not only alcohol, but also its decomposition products, in particular acetaldehyde, which is ten times more dangerous than alcohol itself, enters the waters surrounding the fetus.

Alcohol intoxication has a detrimental effect on the fetus, because its liver, where blood from the placenta first of all enters, does not yet have a special enzyme that decomposes alcohol, and it, not neutralized, spreads throughout the body and causes irreversible changes. Alcohol is especially dangerous in the 7-11th week of pregnancy, when they begin to develop internal organs. It negatively affects their development, causing disturbances and changes. The brain is especially affected. Due to the effects of alcohol, dementia, epilepsy, neuroses, heart and renal disorders, external and internal genital organs are damaged.

Sometimes damage to the psyche and intellect is observed already in early childhood, but most often they are detected when children begin to study. Such a child is intellectually weakened and aggressive. Alcohol has a much stronger effect on a child's body than on an adult's body. Particularly sensitive and easily hurt nervous system and the child's brain.

So, let’s look at the table “The influence of alcohol on the heredity and health of children” and draw conclusions .

Children's destinies

In families of drinking parents	In families of non-drinking parents
Died in the first months of life	44%	8%
Turned out to be inferior, sick	39%	10%
Healthy physically and mentally	17%	82%

Long-term consumption of alcoholic beverages leads to softening of the cortex. Numerous pinpoint hemorrhages are observed; the transmission of excitation from one nerve cell to another. Do not forget the laconic warning words of V.V. Mayakovsky:

Don't drink alcohol.

For those who drink it is poison, for those around it it is torture.

Thus, you have consolidated the ability to predict the chemical properties of unfamiliar organic substances, relying on knowledge of functional groups, repeated the physical and chemical properties of oxygen-containing organic substances, and consolidated the ability to determine the belonging of organic compounds to classes of substances.

III. Homework.

1. Carry out transformations:

2. Explore possible reasons pollution environment near production: methanol, phenol, formaldehyde, acetic acid. Analyze the influence of these substances on natural objects: the atmosphere, water sources, soil, plants, animals and humans. Describe first aid measures for poisoning

Tsepkova E.I.,

chemistry teacher

MAOU "SSOSH No. 2"

chemistry

Grade 10

UMK.Chemistry.10th grade Textbook for general education organizations: basic

level/G.E.Rudzitiis, F.G.Feldman - 2nd edition - M.: Education, 2012.

The level of training is basic.

Lesson topic:Genetic relationship of saturated monohydric alcohols with hydrocarbons.

Total hours allocated for studying the topic: 6 hours.

Lesson location - 4th lesson on topic

Lesson type: lesson of generalization of knowledge.

Lesson objectives: consolidate, generalize and systematize knowledge on oxygen-containing organic compounds, including on the basis of genetic connections between classes of these substances.

Tasks:

educational: repeat basic terms and concepts on the topic, consolidate knowledge about the composition, structure and properties of alcohols;

developing: the ability to analyze, compare, establish connections between the structure and properties of compounds, develop students’ creative abilities and cognitive interest in chemistry;

educational: give Special attention the things we use in life.

Methods: verbal, visual, problem-search, knowledge control.

Equipment: computer, screen, projector, table “Classification of oxygen-containing organic substances”, supporting summary “Functional group determines the properties of a substance.”

Planned learning outcomes

Subject. Know the relationship between the composition, structure and properties of substances. Be able to give examples and draw up equations of chemical reactions that reveal

genetic connections between alcohols and hydrocarbons. Practice the ability to make calculations using chemical equations, if one of the reactants is taken in excess.

Metasubject. Be able to organize educational cooperation and joint activities with the teacher and peers, work individually and in a group (find common decision and resolve conflicts based on coordination of positions and taking into account interests), formulate, argue and defend their opinions.

Personal. To form a holistic worldview that corresponds to the modern level of development of science, based on ideas about the genetic connection between different

classes of organic substances. Develop communication competence.

During the classes.

I. Organizational moment.

II. Guys, today in the lesson we will solve genetic problems, on which we will consolidate the knowledge gained during the study of topics.

The properties of hydrocarbons depend on the chemical, spatial, electronic structure molecules and the nature of chemical bonds.

Study of the structure, chemical properties and methods of producing hydrocarbons various groups shows that they are all genetically related among themselves, i.e. transformation of some hydrocarbons into others is possible:

This allows for targeted synthesis of specified compounds using a series of necessary chemical reactions (chain of transformations).

Task 1. Name the intermediate products in the transformation scheme:

Ethyl alcohol H 2 SO 4 (k), t X HBr Y Na Z Cr 2 O 3 Al 2 O 3 butadiene-1,3

Solution. In this chain of transformations, including 4 reactions, from ethyl alcohol WITH 2 N 5 HE butadiene-1,3 must be obtained CH 2 =CH–CH=CH 2 .
1. When heating alcohols with concentrated sulfuric acid
H 2 SO 4 (water-removing agent) occurs dehydration with the formation of an alkene. The elimination of water from ethyl alcohol leads to the formation of ethylene:

2. Ethylene is a representative of alkenes. Being an unsaturated compound, it is capable of entering into addition reactions. As a result hydrobromination ethylene:

3.When heating bromoethane in the presence sodium metal (Wurtz reaction, n-butane is formed (substance Z):

4.Dehydrogenation n-butane in the presence of a catalyst is one of the methods for producing butadiene-1,3 CH 2 =CH–CH=CH 2
(Section 5.4. Preparation of alkadienes).

Answer:


1. Carry out transformations:

Performing exercises to consolidate knowledge.

Students complete assignments in their workbooks.

Using the genetic connection diagram, indicate from which substances, the formulas of which are given in the task, alcohols can be obtained in one stage? Write down the equations for the corresponding reactions. Name the starting materials and products of the reaction. For suffixes in the names of hydrocarbons and halogenated hydrocarbons, underline the multiplicity of the bond accordingly.

Name the class of substances and establish a genetic relationship (show this with arrows).

Carry out transformations:

CaC 2 → A → B → H 3 C-CH 2 -Cl → B → H 3 C-CH 2 -O-C 3 H 7

CaC 2 + 2H 2 O → HC≡CH + Ca(OH) 2 A

2) HC≡CH + 2H 2 → H 3 C-CH 3 B

3) H 3 C-CH 3 + C1 2 → H 3 C-CH 2 -C1 + HC1

4) H 3 C-CH 2 -C1 + KOH (aq.) → H 3 C-CH 2 -OH + KS1 B

5) H 3 C-CH 2 -OH + HO-C 3 H 7 → H 3 C-CH 2 -O-C 3 H 7 + H 2 O

Now let's complicate our task a little. . Make a chain of transformations from proposed connections. Among the formulas of substances there are “extra” ones. How does this task compare to the previous one?

a )C 6H5- OH, b) C 4H8, c) C 6H5- Br, d) C 5H11-Cl, e) C 6H6, f) C 3H6, g )HC≡CH, h)H 2 C =CH 2 i) CH 4 .

CH 4 → HC≡CH → C 6 H 6 → C 6 H 5 -Br → C 6 H 5 -OH

2CH 4 → HC≡CH + 3H 2

3HC≡CH → C 6 H 6

3. C 6 H 6 + Br 2 → C 6 H 5 Br + HBr

4. C 6 H 5 -Br + KOH → C 6 H 5 -OH + KBr

Reinforcing the properties of hydrocarbons in the form of a game “No-yes”»
1. Can you get alcohol from ethene? (Yes)
2. Is ethanol found in plant leaves? (No)
3. Fermentation of sugary substances produces methanol? (No)
4. From wood shavings Is it possible to produce ethanol by fermentation? (No)
5. If you freeze potatoes, can you get ethyl alcohol? (Yes)

.Reflective test:
1. This will be useful to me in life.
2. There was a lot to think about during the lesson.
3. I received answers to all the questions I had.
4. I worked conscientiously during the lesson.

Homework. Pov.§20-21, transformation schemes exercises 14,15*,

Carry out the transformations:
C2H5OH-C2H5CL-C2H5OH-C2H5OC2H5
CO2
Bibliography

Chemistry.Organic chemistry.10th grade: textbook. for general education institutions: basic level G.E. Rudzitis, F.G. Feldman. – 13th ed.-M.: Education, 2009.

Chemistry 8-11 grade ( thematic planning based on the textbook by G.E. Rudzitis, F.G. Feldman) / comp. Breiger L.M.-Volgograd: Teacher-AST, 1999

Chemistry. Large reference book for preparing for the Unified State Exam: educational Toolkit/ Edited by V.N. Doronkina. - 2nd edition, revised - Rostov n/D: Legion, 2016.

Surovtseva R.P. and others. Chemistry. 10-11 grades: Methodological manual. - M.: Bustard, 2000.

Tazhibaeva Asemgul Isintaevna

Teacher at Kamennobrod Secondary School

Chemistry lesson in 11th grade

Lesson topic: Genetic relationships between hydrocarbons, alcohols, aldehydes, alcohols, carboxylic acids.

Lesson type: lesson of generalization of knowledge.

Lesson objectives: consolidate, generalize and systematize knowledge on oxygen-containing organic compounds, including on the basis of genetic connections between classes of these substances. Strengthen the ability to predict the chemical properties of unfamiliar organic substances based on knowledge of functional groups. To develop in students demonstrative speech, the ability to use chemical terminology, conduct, observe and describe a chemical experiment. To cultivate the need for knowledge about the substances with which we come into contact in life.

Methods: verbal, visual, practical, problem-search, knowledge control.

Reagents: acetylsalicylic acid (aspirin), water, ferric chloride (III), glucose solution, universal indicator, copper (II) sulfate solution, sodium hydroxide solution, egg white, ethanol, 1-butanol, acetic acid, stearic acid.

Equipment: computer, screen, projector, table “Classification of oxygen-containing organic substances”, supporting note “Functional group determines the properties of a substance”, mortar and pestle, glass rod, alcohol lamp, test tube holder, funnel, filter, glasses, rack with test tubes, pipette, graduated cylinder on 10 ml.

I. Organizational moment.

Today in class:

1) You will strengthen the ability to predict the chemical properties of unfamiliar organic substances based on knowledge of functional groups.

2) You will find out what functional groups you know are included in the most famous antipyretic drug.

3) You will find functional groups in a sweet-tasting substance that is used in medicine as a nutrient and component of blood-replacing fluids.

4) You will see how you can get pure silver.

5) We will talk about the physiological effects of ethyl alcohol.

6) We will discuss the consequences of drinking alcoholic beverages by pregnant women.

7) You will be pleasantly surprised: it turns out that you already know so much!

II. Repetition and generalization of students' acquired knowledge.

1. Classification of oxygen-containing organic compounds.

We begin the generalization of the material with the classification of oxygen-containing organic substances. To do this, we will use the table “Classification of oxygen-containing organic compounds”. During frontal work, we will repeat oxygen-containing functional groups.

In organic chemistry, there are three most important functional groups, including oxygen atoms:hydroxyl, carbonyl Andcarboxyl. The latter can be considered as a combination of the previous two. Depending on which atoms or groups of atoms these functional groups are associated with, oxygen-containing substances are divided into alcohols, phenols, aldehydes, ketones and carboxylic acids.

Let's consider these functional groups and their effect on the physical and chemical properties of substances.

Viewing a video clip.

You already know that this is not the only possible classification sign. There can be several identical functional groups in a molecule, and pay attention to the corresponding row of the table.

The next line reflects the classification of substances by the type of radical associated with the functional group. I would like to draw attention to the fact that, unlike alcohols, aldehydes, ketones and carboxylic acids, hydroxyarenes are classified into a separate class of compounds - phenols.

The number of functional groups and the structure of the radical determine the general molecular formula of the substances. In this table they are given only for the limiting representatives of classes with one functional group.

All classes of compounds that “fit” in the table aremonofunctional, i.e., they have only one oxygen-containing function.

To consolidate the material on the classification and nomenclature of oxygen-containing substances, I give several formulas of compounds and ask students to determine “their place” in the given classification and give a name.

formula

Relationship between the structure and properties of oxygen-containing compounds.

The nature of the functional group has a significant impact on the physical properties of substances of this class and largely determines its chemical properties.

The concept of “physical properties” includes the state of aggregation of substances.

Aggregate state of linear connections of different classes:

Number of atoms C in a molecule

The homologous series of aldehydes begins with a gaseous substance at room temperature - formaldehyde, and there are no gases among monohydric alcohols and carboxylic acids. What is this connected with?

Molecules of alcohols and acids are additionally connected to each other by hydrogen bonds.

The teacher asks students to formulate the definition of “hydrogen bond” (this is an intermolecular bond between the oxygen of one molecule and the hydroxyl hydrogen of another molecule), corrects it and, if necessary, dictates for writing: a chemical bond between an electron-deficient hydrogen atom and an electron-rich atom of an element with high electronegativity (F , O , N ) is calledhydrogen.

Now compare the boiling points (°C) of the first five homologs of substances of three classes.

Number of atoms C in a molecule

What can you say after looking at the tables?

In the homologous series of alcohols and carboxylic acids there are no gaseous substances and the boiling points of the substances are high. This is due to the presence of hydrogen bonds between molecules. Due to hydrogen bonds, molecules become associated (as if cross-linked), therefore, in order for the molecules to become free and acquire volatility, it is necessary to expend additional energy to break these bonds.

What can be said about the solubility of alcohols, aldehydes and carboxylic acids in water? (Demonstration of the solubility in water of alcohols - ethyl, propyl, butyl and acids - formic, acetic, propionic, butyric and stearic. A solution of formic aldehyde in water is also demonstrated.)

When answering, the scheme of formation of hydrogen bonds between molecules of acid and water, alcohols, and acids is used.

It should be noted that with increasing molecular weight, the solubility of alcohols and acids in water decreases. The larger the hydrocarbon radical in an alcohol or acid molecule, the more difficult it is for the OH group to keep the molecule in solution due to the formation of weak hydrogen bonds.

3. Genetic relationship between different classes of oxygen-containing compounds.

I draw on the board the formulas of a number of compounds containing one carbon atom:

CH 4 →CH 3 OH → HCOH → HCOOH→ CO 2

Why are they studied in this order in the organic chemistry course?

How does the oxidation state of a carbon atom change?

Students dictate the line: -4, -2, 0, +2, +4

It now becomes clear that each subsequent compound is an increasingly oxidized form of the previous one. From here it is obvious that one should move along the genetic series from left to right using oxidation reactions, and in the opposite direction using reduction processes.

Do ketones fall out of this “circle of relatives”? Of course not. Their predecessors are secondary alcohols.

The chemical properties of each class of substances were discussed in detail in the corresponding lessons. To summarize this material, I offered homework assignments on interconversions in a somewhat unusual form.

1. Compound with molecular formulaC 3 H 8 O subjected to dehydrogenation, resulting in a product with the compositionC 3 H 6 O . This substance undergoes a “silver mirror” reaction, forming the compoundC 3 H 6 O 2 . By treating the latter substance with calcium hydroxide, a substance was obtained that is used as a food additive under the code E 282. It prevents the growth of mold in bakery and confectionery products and, in addition, is found in products such as Swiss cheese. Determine the formula of the additive E 282, write the equations for the reactions mentioned and name all the organic substances.

Solution :

CH 3 –CH 2 –CH 2 –OH → CH 3 –CH 2 – COH + H 2 ( cat. – Cu, 200-300 °C)

CH 3 –CH 2 – COH + Ag 2 O → CH 3 –CH 2 – COOH + 2Ag (simplified equation, ammonia solution of silver oxide)

2CH 3 –CH 2 –COOH+WITHa(OH) 2 → (CH 3 –CH 2 – COO) 2 Ca+2H 2 O.

Answer: calcium propionate.

2. Composition compoundC 4 H 8 Cl 2 with a straight carbon skeleton heated with an aqueous solutionNaOH and obtained an organic substance, which, upon oxidationCu(OH) 2 turned intoC 4 H 8 O 2 . Determine the structure of the original compound.

Solution: if 2 chlorine atoms are located at different carbon atoms, then when treated with alkali we would get a dihydric alcohol that would not oxidizeCu(OH) 2 . If 2 chlorine atoms were located at one carbon atom in the middle of the chain, then when treated with alkali, a ketone would be obtained, which does not oxidizeCu(OH) 2. Then, the desired connection is1,1-dichlorobutane.

CH 3 –CH 2 –CH 2 – CHCl 2 + 2NaOH → CH 3 –CH 2 –CH 2 – COH + 2NaCl + H 2 O

CH 3 –CH 2 –CH 2 – COH + 2Cu(OH) 2 →CH 3 –CH 2 –CH 2 – COOH + Cu 2 O+2H 2 O

3. When 19.2 g of sodium salt of saturated monobasic acid was heated with sodium hydroxide, 21.2 g of sodium carbonate was formed. Name the acid.

Solution:

When heated, decarboxylation occurs:

R-COONa + NaOH → RH + Na 2 CO 3

υ (Na 2 CO 3 ) = 21,2 / 106 = 0,2 mole

υ (R-COONa) = 0.2 mole

M(R-COONa) = 19.2 / 0.2 = 96 G/ mole

M(R-COOH) = M(R-COONa) –M(Na) + M(H) = 96-23+1= 74G/ mole

In accordance with the general formula for saturated monobasic carboxylic acids, to determine the number of carbon atoms, it is necessary to solve the equation:

12n + 2n + 32= 74

n=3

Answer: propionic acid.

To consolidate knowledge about the chemical properties of oxygen-containing organic substances, we will perform a test.

1 option

The following formulas correspond to saturated monohydric alcohols:
A) CH 2 O
B) C 4 H 10 O
IN) C 2 H 6 O
G) CH 4 O
D) C 2 H 4 O 2

It contains a combination of two principles,
One is in the birth of mirrors.
Of course, not for contemplation,
And for the science of understanding.
...And in the kingdom of the forest she is found,
The little brothers are her friends here,
Their hearts are given to them completely...

options:
A) picric acid
B) formic acid
B) acetic acid
D) carboxyl group
D) benzoic acid

Ethanol reacts with substances:
A) NaOH
B) Na
IN) HCl
G) CH 3 COOH
D) FeCl 3

A qualitative reaction to phenols is a reaction with
A) NaOH
B) Cu(OH) 2
IN) CuO
G) FeCl 3
D) HNO 3

Ethanal reacts with substances
A) methanol
B) hydrogen
B) ammonia solution of silver oxide
D) copper (II) hydroxide
D) hydrogen chloride

Option 2

Aldehydes can be obtained
A) oxidation of alkenes
B) oxidation of alcohols
B) hydration of alkynes
D) when heating calcium salts of carboxylic acids
D) hydration of alkenes

The functional group of alcohols is
A) COH
B) OH
IN) COOH
G) N.H. 2
D) NO 2

2-methylbutanol-2
A) unsaturated alcohol
B) limiting alcohol
B) monohydric alcohol
D) tertiary alcohol
D) aldehyde

Did you observe the reaction?
A) for polyhydric alcohols
B) alcohol oxidation
B) interaction of phenol with iron (III) chloride
D) “silver mirror”
D) “copper mirror”

Acetic acid reacts with substances
A) hydrogen
B) chlorine
B) propanol
D) sodium hydroxide
D) metanalem

Students fill out their answers in the table:

1, 2 var.

If you connect the correct answers with a solid line, you get the number “5”.

Group work of students.

Assignment for group 1

Goals:

Reagents and equipment: acetylsalicylic acid (aspirin), water, iron(III) chloride; mortar and pestle, glass rod, alcohol lamp, test tube holder, funnel, filter, glasses, rack with test tubes, pipette, 10 ml graduated cylinder.

Experiment 1. Evidence of the absence of phenolic hydroxyl in acetylsalicylic acid (aspirin).

Place 2-3 grains of acetylsalicylic acid into a test tube, add 1 ml of water and shake vigorously. Add 1-2 drops of iron(III) chloride solution to the resulting solution. What are you observing? Draw conclusions.

No purple color appears. Therefore, in acetylsalicylic acidNOOS-S 6 N 4 -O-CO-CH 3 there is no free phenolic group, since this substance is an ester formed by acetic and salicylic acids.

Experiment 2. Hydrolysis of acetylsalicylic acid.

A crushed acetylsalicylic acid tablet is placed in a test tube and 10 ml of water is added. Bring the contents of the test tube to a boil and boil for 0.5-1 minutes. Filter the solution. Then 1-2 drops of iron(III) chloride solution are added to the resulting filtrate. What are you observing? Draw conclusions.

Write down the reaction equation:

Complete the work by filling out a table that contains the following columns: operation performed, reagent, observations, conclusion.

A purple color appears, indicating the release of salicylic acid containing a free phenolic group. As an ester, acetylsalicylic acid is easily hydrolyzed when boiled with water.

Assignment for group 2

1. Consider the structural formulas of substances, name the functional groups.

2. Do lab work"Detection of functional groups in the glucose molecule".

Goals: consolidate students' knowledge of qualitative reactions of organic compounds, develop skills in experimental determination of functional groups.

Reagents and equipment: solution glucose, universal indicator, copper (II) sulfate solution, sodium hydroxide solution, alcohol lamp, test tube holder, matches, 10 ml graduated cylinder.

2.1. Pour 2 ml of glucose solution into a test tube. Using a universal indicator, draw a conclusion about the presence or absence of a carboxyl group.

2.2. Prepare copper (II) hydroxide: pour 1 ml of copper (II) sulfate into a test tube and add sodium hydroxide to it. Add 1 ml of glucose to the resulting precipitate and shake. What are you observing? What functional groups is this reaction typical for?

2.3. Heat the mixture obtained in experiment No. 2. Note the changes. What functional group is this reaction typical for?

2.4. Complete the work by filling out a table that contains the following columns: operation performed, reagent, observations, conclusion.

Demonstration experience. Interaction of glucose solution with ammonia solution of silver oxide.

Work results:

- there is no carboxyl group, because the solution has a neutral reaction to the indicator;

- the precipitate of copper (II) hydroxide dissolves and a bright blue color appears, characteristic of polyhydric alcohols;

- when this solution is heated, a yellow precipitate of copper (I) hydroxide precipitates, which turns red upon further heating, indicating the presence of an aldehyde group.

Conclusion. Thus, the glucose molecule contains carbonyl and several hydroxyl groups and is an aldehyde alcohol.

Assignment for group 3

Physiological effect of ethanol

1. What is the effect of ethanol on living organisms?

2. Using the equipment and reagents available on the table, demonstrate the effect of ethanol on living organisms. Comment on what you see.

Purpose of the experience: convince students that alcohol denatures proteins and irreversibly disrupts their structure and properties.

Equipment and reagents: rack with test tubes, pipette, 10 ml graduated cylinder, egg white, ethanol, water.

Progress of the experiment: Pour 2 ml of egg white into 2 test tubes. Add 8 ml of water to one, and the same amount of ethanol to the other.

In the first test tube, the protein dissolves and is well absorbed by the body. In the second test tube, a dense white precipitate forms - proteins do not dissolve in alcohol, alcohol takes away water from proteins. As a result, the structure and properties of the protein and its functions are disrupted.

3. Tell us about the effect of ethyl alcohol on various human organs and organ systems.

Explain the consequences of drinking alcohol to pregnant women.

Student performances.

Since ancient times, man has known a large number of toxic substances, all of which differ in the strength of their effect on the body. Among them stands out a substance that is known in medicine as a strong protoplasmic poison - ethyl alcohol. The mortality rate from alcoholism exceeds the number of deaths caused by all infectious diseases combined.

Burning the mucous membrane of the mouth, pharynx, and esophagus, it enters the gastrointestinal tract. Unlike many other substances, alcohol is quickly and completely absorbed in the stomach. Easily crossing biological membranes, after about an hour it reaches its maximum concentration in the blood.

Alcohol molecules quickly penetrate biological membranes into the blood compared to water molecules. Ethyl alcohol molecules can easily cross biological membranes due to their small size, weak polarization, the formation of hydrogen bonds with water molecules, and the good solubility of alcohol in fats.

Quickly absorbed into the blood and dissolving well in the intercellular fluid, alcohol enters all cells of the body. Scientists have found that, by disrupting the functions of cells, it causes their death: when drinking 100 g of beer, about 3000 brain cells die, 100 g of wine - 500, 100 g of vodka - 7500, contact of red blood cells with alcohol molecules leads to the coagulation of blood cells.

The liver neutralizes toxic substances that enter the blood. Doctors call this organ a target for alcohol, since 90% of ethanol is neutralized in it. Chemical processes of ethyl alcohol oxidation occur in the liver.

We recall with students the stages of the alcohol oxidation process:

Ethyl alcohol is oxidized to final decomposition products only if the daily consumption of ethanol does not exceed 20 g. If the dose is exceeded, then intermediate decomposition products accumulate in the body.

This leads to a number of negative side effects: increased formation of fat and its accumulation in liver cells; the accumulation of peroxide compounds that can destroy cell membranes, resulting in the contents of the cells leaking out through the formed pores; very undesirable phenomena, the combination of which leads to liver destruction - cirrhosis.

Acetaldehyde is 30 times more toxic than ethyl alcohol. In addition, as a result of various biochemical reactions in tissues and organs, including the brain, the formation of tetrahydropapaveroline is possible, the structure and properties of which resemble well-known psychotropic drugs - morphine and cannabinol. Doctors have proven that it is acetaldehyde that causes mutations and various deformities in embryos.

Acetic acid enhances the synthesis of fatty acids and leads to fatty degeneration of the liver.

While studying the physical properties of alcohols, we addressed the issue of changes in their toxicity in the homologous series of monohydric alcohols. As the molecular weight of substance molecules increases, their narcotic properties increase. If we compare ethyl and pentyl alcohols, the molecular weight of the latter is 2 times greater, and its toxicity is 20 times greater. Alcohols containing three to five carbon atoms form so-called fusel oils, the presence of which in alcoholic beverages increases their toxic properties.

In this series, the exception is methanol - the strongest poison. When 1-2 teaspoons enter the body, the optic nerve is affected, which leads to complete blindness, and consumption of 30-100 ml leads to death. The danger is enhanced by the similarity of methyl alcohol to ethyl alcohol in properties, appearance, and smell.

Together with the students, we try to find the cause of this phenomenon. They put forward various hypotheses. We dwell on the fact that the factors that increase the toxicity of methyl alcohol include the small size of the molecules (high speed of distribution), as well as the fact that the intermediate products of its oxidation - formic aldehyde and formic acid - are strong poisons.

Alcohol that is not neutralized by the liver and the toxic products of its breakdown re-enter the bloodstream and are distributed throughout the body, remaining in it for a long time. For example, alcohol is found unchanged in the brain 20 days after taking it.

We draw students' attention to how alcohol and its breakdown products are eliminated from the body.

C 2 H 5 OH

Unfortunately, recently, alcohol consumption, like smoking, has become widespread among women. The influence of alcohol on offspring goes in two directions.

Firstly, alcohol consumption is accompanied by profound changes in the sexual sphere of both men and women. Alcohol and its decomposition products can affect both female and male reproductive cells even before fertilization - their genetic information changes (see Fig. “Healthy (1) and pathological (2) sperm”).

If alcohol consumption is prolonged, the activity of the reproductive system is disrupted, it begins to produce defective germ cells.

Secondly, alcohol directly affects the embryo. Constant consumption of 75-80 g of vodka, cognac or 120-150 g of weaker alcoholic drinks (beer) can cause fetal alcohol syndrome. Through the placenta, not only alcohol, but also its decomposition products, in particular acetaldehyde, which is ten times more dangerous than alcohol itself, enters the waters surrounding the fetus.

Alcohol intoxication has a detrimental effect on the fetus, because its liver, where blood from the placenta first of all enters, does not yet have a special enzyme that decomposes alcohol, and it, not neutralized, spreads throughout the body and causes irreversible changes. Alcohol is especially dangerous in the 7-11th week of pregnancy, when internal organs begin to develop. It negatively affects their development, causing disturbances and changes. The brain is especially affected. Due to the effects of alcohol, dementia, epilepsy, neuroses, heart and kidney disorders can develop, and damage to the external and internal genital organs can occur.

Sometimes damage to the psyche and intellect is observed already in early childhood, but most often they are detected when children begin to study. Such a child is intellectually weakened and aggressive. Alcohol has a much stronger effect on a child's body than on an adult's body. The child’s nervous system and brain are especially sensitive and vulnerable.

So, let’s look at the table “The influence of alcohol on the heredity and health of children” and draw conclusions .

Children's destinies

Long-term consumption of alcoholic beverages leads to softening of the cortex. Numerous pinpoint hemorrhages are observed; the transmission of excitation from one nerve cell to another is disrupted. Do not forget the laconic warning words of V.V. Mayakovsky:

Don't drink alcohol.

For those who drink it is poison, for those around it it is torture.

Thus, you have consolidated the ability to predict the chemical properties of unfamiliar organic substances, relying on knowledge of functional groups, repeated the physical and chemical properties of oxygen-containing organic substances, and consolidated the ability to determine the belonging of organic compounds to classes of substances.

III. Homework.

1. Carry out transformations:

2. Study the possible causes of environmental pollution near production: methanol, phenol, formaldehyde, acetic acid. Analyze the influence of these substances on natural objects: the atmosphere, water sources, soil, plants, animals and humans. Describe first aid measures for poisoning