What types of isomers are characteristic of alcohols. Alcohols - nomenclature, preparation, chemical properties

Alcohols are hydrocarbon derivatives containing one or more -OH groups, called a hydroxyl group or hydroxyl.

Alcohols are classified:

1. According to the number of hydroxyl groups contained in the molecule, alcohols are divided into monohydric (with one hydroxyl), diatomic (with two hydroxyls), triatomic (with three hydroxyls) and polyatomic.

Like saturated hydrocarbons, monohydric alcohols form a naturally constructed series of homologues:

As in other homologous series, each member of the alcohol series differs in composition from the previous and subsequent members by a homologous difference (-CH 2 -).

2. Depending on which carbon atom the hydroxyl is located at, primary, secondary and tertiary alcohols are distinguished. The molecules of primary alcohols contain a -CH 2 OH group associated with one radical or with a hydrogen atom in methanol (hydroxyl at the primary carbon atom). Secondary alcohols are characterized by a >CHOH group linked to two radicals (hydroxyl at the secondary carbon atom). In the molecules of tertiary alcohols there is a >C-OH group associated with three radicals (hydroxyl at the tertiary carbon atom). Denoting the radical by R, we can write the formulas of these alcohols in general form:

In accordance with the IUPAC nomenclature, when constructing the name of a monohydric alcohol, the suffix -ol is added to the name of the parent hydrocarbon. If a compound contains higher functions, the hydroxyl group is designated by the prefix hydroxy- (in Russian the prefix oxy- is often used). The longest unbranched chain of carbon atoms, which includes a carbon atom bound to a hydroxyl group, is selected as the main chain; if the compound is unsaturated, then a multiple bond is also included in this chain. It should be noted that when determining the beginning of numbering, the hydroxyl function usually takes precedence over the halogen, double bond and alkyl, therefore, numbering begins from the end of the chain closer to which the hydroxyl group is located:

The simplest alcohols are named by the radicals with which the hydroxyl group is connected: (CH 3) 2 CHOH - isopropyl alcohol, (CH 3) 3 SON - tert-butyl alcohol.

A rational nomenclature for alcohols is often used. According to this nomenclature, alcohols are considered as derivatives of methyl alcohol - carbinol:

This system is convenient in cases where the name of the radical is simple and easy to construct.

2. Physical properties of alcohols

Alcohols have higher boiling points and are significantly less volatile, have higher melting points, and are more soluble in water than the corresponding hydrocarbons; however, the difference decreases with increasing molecular weight.

The difference in physical properties is due to the high polarity of the hydroxyl group, which leads to the association of alcohol molecules due to hydrogen bonding:

Thus, the higher boiling points of alcohols compared to the boiling points of the corresponding hydrocarbons are due to the need to break hydrogen bonds when molecules pass into the gas phase, which requires additional energy. On the other hand, this type of association leads to an increase in molecular weight, which naturally causes a decrease in volatility.

Alcohols with low molecular weight are highly soluble in water, this is understandable if we take into account the possibility of forming hydrogen bonds with water molecules (water itself is associated to a very large extent). In methyl alcohol, the hydroxyl group makes up almost half the mass of the molecule; It is not surprising, therefore, that methanol is miscible with water in all respects. As the size of the hydrocarbon chain in alcohol increases, the influence of the hydroxyl group on the properties of alcohols decreases; accordingly, the solubility of substances in water decreases and their solubility in hydrocarbons increases. Physical properties monohydric alcohols with high molecular weight are already very similar to the properties of the corresponding hydrocarbons.

Glycols. Hydroxyl groups in glycols are found at various carbon atoms. Glycols with two hydroxyls on one carbon atom are unstable. They split off water to form aldehydes or ketones.

Isomerism of glycols determined by the mutual arrangement of hydroxyl groups and the isomerism of the carbon skeleton. Depending on the relative position of the OH– groups, there are α-, β-, γ-, δ-, ... glycols. Depending on the nature of the carbon atoms bearing hydroxyls, glycols can be primary-secondary, primary-tertiary, diprimary, disecondary, etc.

Names of glycols can be given in two ways. According to IUPAC nomenclature, the suffix is added to the name of the main carbon chain –diol and indicate the numbers of carbon atoms of the longest carbon chain bearing hydroxyl groups. Titles α- glycols can be derived from the name of the corresponding ethylene carbon with the addition of the word glycol. The classification and names of glycols are given below using butanediols as an example:

Methods of obtaining. In principle, glycols can be obtained by all conventional synthetic methods for the preparation of alcohols.

An example is the following reactions.

– Hydrolysis of dihalogen derivatives of saturated hydrocarbons and halohydrins:

– Hydration α -oxides in an acidic environment:

– Olefin oxidation potassium permanganate in a dilute aqueous weakly alkaline solution (Wagner reaction) or hydrogen peroxide in the presence of catalysts (CrO 3):

Physical properties. Lower glycols are highly soluble in water. Their density is higher than that of monohydric alcohols. Accordingly, the boiling point is higher due to the significant association of molecules: for example, ethylene glycol boils at a temperature of 197.2 °C; propylene glycol - at a temperature of 189 °C and butanediol-1,4 - at a temperature of 230 °C.

Chemical properties. Everything said earlier about the properties of the corresponding monohydric alcohols also applies to glycols. It should be remembered that either one hydroxyl or both at once can react. – Oxidation of diprimary glycols gives aldehydes:

– During oxidation α- glycols with periodic acid the bond between carbon atoms bearing hydroxyls is broken, and the corresponding aldehydes or ketones are formed:

The method is of great importance for establishing the structure α- glycols

-Results intramolecular elimination of water glycols to a large extent depend on glycol type.

Dehydration of α-glycols proceeds with the formation of aldehydes or ketones, γ-glycols Due to the atoms of hydroxyl groups, water is eliminated to form heterocyclic compounds - tetrahydrofuran or its homologues:

The first reaction occurs through the formation of a carbonium ion followed by the movement of a hydrogen atom with its electron pair:

At vapor phase dehydration over Al 2 O 3 α- two-tertiary glycols, called pinacones, diene hydrocarbons are obtained:

– Intermolecular dehydration leads to the formation of hydroxy ethers or cyclic ethers:

The boiling point of diethylene glycol is 245.5 °C. It is used as a solvent to fill brake hydraulic systems, when finishing and dyeing fabrics.

Among cyclic ethers, dioxane is the most widely used solvent. It was obtained for the first time by A.E. Favorsky heating of ethylene glycol with sulfuric acid:

ethylene glycol is a viscous colorless liquid, sweetish in taste, boiling point = 197.2 °C. On an industrial scale, it is obtained from ethylene according to three schemes.

When mixed with water, ethylene glycol greatly lowers its freezing point. For example, A 60% aqueous solution of glycol freezes at a temperature of – 49 °C and is successfully used as antifreeze. The high hygroscopicity of ethylene glycol is used to prepare printing inks. A large amount of ethylene glycol is used to produce film-forming materials, varnishes, paints, synthetic fibers (for example, lavsan - polyethylene terephthalate), dioxane, diethylene glycol and other products.

Polyhydric alcohols

Polyhydric alcohols are alcohols that have several OH hydroxyl groups.
Polyhydric alcohols with a small number of carbon atoms are viscous liquids, higher alcohols are solids. Polyhydric alcohols can be obtained by the same synthetic methods as saturated polyhydric alcohols. Preparation of alcohols

1. Obtaining ethyl alcohol (or wine alcohol) by fermentation of carbohydrates:
C2H12O6 => C2H5-OH + CO2

The essence of fermentation is that one of the simplest sugars, glucose, produced technically from starch, breaks down into ethyl alcohol and carbon dioxide under the influence of yeast. It has been established that the fermentation process is caused not by the microorganisms themselves, but by the substances they secrete - zymases. To obtain ethyl alcohol, vegetable raw materials rich in starch are usually used: potato tubers, bread grains, rice grains, etc.

2. Hydration of ethylene in the presence of sulfuric acid or phosphoric acid
CH2=CH2 + KOH => C2H5-OH

3. When haloalkanes react with alkali:

4. During the oxidation of alkenes

5. Hydrolysis of fats: this reaction produces the well-known alcohol - glycerin

Properties of alcohols

1) Combustion: Like most organic substances, alcohols burn to form carbon dioxide and water:
C2H5-OH + 3O2 -->2CO2 + 3H2O
When they burn, a lot of heat is released, which is often used in laboratories. Lower alcohols burn with an almost colorless flame, while higher alcohols have a yellowish flame due to incomplete combustion of carbon.

2) Reaction with alkali metals
C2H5-OH + 2Na --> 2C2H5-ONa + H2
This reaction releases hydrogen and produces sodium alkoxide. Alcoholates are similar to salts of a very weak acid, and they are also easily hydrolyzed. Alcoholates are extremely unstable and when exposed to water, they decompose into alcohol and alkali.

3) Reaction with hydrogen halide C2H5-OH + HBr --> CH3-CH2-Br + H2O
This reaction produces a haloalkane (bromoethane and water). This chemical reaction of alcohols is caused not only by the hydrogen atom in the hydroxyl group, but by the entire hydroxyl group! But this reaction is reversible: for it to occur, you need to use a water-removing agent, such as sulfuric acid.

4) Intramolecular dehydration (in the presence of H2SO4 catalyst)

The abstraction of a hydrogen atom from an alcohol can occur in its own. This reaction is an intermolecular dehydration reaction. For example, like this:

During the reaction, ether and water are formed.

5) reaction with carboxylic acids:

If you add a carboxylic acid, such as acetic acid, to an alcohol, an ether will form. But esters are less stable than ethers. If the reaction of the formation of an ether is almost irreversible, then the formation of an ester is a reversible process. Esters easily undergo hydrolysis, breaking down into alcohol and carboxylic acid.

6) Oxidation of alcohols. Alcohols are not oxidized by atmospheric oxygen at ordinary temperatures, but when heated in the presence of catalysts, oxidation occurs. An example is copper oxide (CuO), potassium permanganate (KMnO4), chromium mixture. The action of oxidizing agents produces different products and depends on the structure of the original alcohol. Thus, primary alcohols are converted into aldehydes (reaction A), secondary alcohols are converted into ketones (reaction B), and tertiary alcohols are resistant to oxidizing agents.
- a) for primary alcohols

- b) for secondary alcohols

- c) tertiary alcohols are not oxidized by copper oxide!

Concerning polyhydric alcohols, they have a sweetish taste, but some of them are poisonous. The properties of polyhydric alcohols are similar to monohydric alcohols, the difference being that the reaction occurs not one at a time to the hydroxyl group, but several at once.
One of the main differences is that polyhydric alcohols easily react with copper hydroxide. This produces a transparent solution of a bright blue-violet color. It is this reaction that can detect the presence of a polyhydric alcohol in any solution.
Interact with nitric acid:

Ethylene glycol is a typical representative of polyhydric alcohols. His chemical formula CH2OH - CH2OH. - dihydric alcohol. This is a sweet liquid that can dissolve perfectly in water in any proportions. IN chemical reactions either one hydroxyl group (-OH) or two at the same time can participate. Ethylene glycol - its solutions - are widely used as an anti-icing agent (antifreeze). An ethylene glycol solution freezes at a temperature of -340C, which can replace water in the cold season, for example, for cooling cars.
With all the benefits of ethylene glycol, you need to take into account that it is a very strong poison!

Alcohols(or alkanols) are organic substances whose molecules contain one or more hydroxyl groups (-OH groups) connected to a hydrocarbon radical.

Classification of alcohols

According to the number of hydroxyl groups(atomicity) alcohols are divided into:

Monatomic, For example:

Diatomic(glycols), for example:

Triatomic, For example:

According to the nature of the hydrocarbon radical The following alcohols are released:

Limit containing only saturated hydrocarbon radicals in the molecule, for example:

Unlimited containing multiple (double and triple) bonds between carbon atoms in the molecule, for example:

Aromatic, i.e. alcohols containing a benzene ring and a hydroxyl group in the molecule, connected to each other not directly, but through carbon atoms, for example:

Organic substances containing hydroxyl groups in the molecule, connected directly to the carbon atom of the benzene ring, differ significantly in chemical properties from alcohols and are therefore isolated in independent class organic compounds- phenols.

For example:

There are also polyhydric (polyhydric alcohols) containing more than three hydroxyl groups in the molecule. For example, the simplest hexahydric alcohol hexaol (sorbitol)

Nomenclature and isomerism of alcohols

When forming the names of alcohols, a (generic) suffix is added to the name of the hydrocarbon corresponding to the alcohol. ol.

The numbers after the suffix indicate the position of the hydroxyl group in the main chain, and the prefixes di-, tri-, tetra- etc. - their number:

In the numbering of carbon atoms in the main chain, the position of the hydroxyl group takes precedence over the position of multiple bonds:

Starting from the third member of the homologous series, alcohols exhibit isomerism of the position of the functional group (propanol-1 and propanol-2), and from the fourth, isomerism of the carbon skeleton (butanol-1, 2-methylpropanol-1). They are also characterized by interclass isomerism - alcohols are isomeric to ethers:

Let's give a name to the alcohol, the formula of which is given below:

Name construction order:

1. The carbon chain is numbered from the end closest to the –OH group.
2. The main chain contains 7 C atoms, which means the corresponding hydrocarbon is heptane.
3. The number of –OH groups is 2, the prefix is “di”.
4. Hydroxyl groups are located at 2 and 3 carbon atoms, n = 2 and 4.

Alcohol name: heptanediol-2,4

Physical properties of alcohols

Alcohols can form hydrogen bonds both between alcohol molecules and between alcohol and water molecules. Hydrogen bonds arise from the interaction of a partially positively charged hydrogen atom of one alcohol molecule and a partially negatively charged oxygen atom of another molecule. It is thanks to hydrogen bonds between molecules that alcohols have abnormally high boiling points for their molecular weight. Thus, propane with a relative molecular weight of 44 at normal conditions is a gas, and the simplest of alcohols is methanol, having a relative molecular weight of 32, under normal conditions it is a liquid.

The lower and middle members of a series of saturated monohydric alcohols containing from 1 to 11 carbon atoms are liquids. Higher alcohols (starting from C12H25OH) at room temperature - solids. Lower alcohols have an alcoholic odor and a pungent taste; they are highly soluble in water. As the carbon radical increases, the solubility of alcohols in water decreases, and octanol no longer mixes with water.

Chemical properties of alcohols

The properties of organic substances are determined by their composition and structure. Alcohols confirm general rule. Their molecules include hydrocarbon and hydroxyl groups, therefore Chemical properties alcohols are determined by the interaction of these groups with each other.

The properties characteristic of this class of compounds are due to the presence of a hydroxyl group.

Interaction of alcohols with alkali and alkaline earth metals. To identify the effect of a hydrocarbon radical on a hydroxyl group, it is necessary to compare the properties of a substance containing a hydroxyl group and a hydrocarbon radical, on the one hand, and a substance containing a hydroxyl group and not containing a hydrocarbon radical, on the other. Such substances can be, for example, ethanol (or other alcohol) and water. The hydrogen of the hydroxyl group of alcohol molecules and water molecules is capable of being reduced by alkali and alkaline earth metals (replaced by them)
Interaction of alcohols with hydrogen halides. Substitution of a hydroxyl group with a halogen leads to the formation of haloalkanes. For example:
This reaction is reversible.
Intermolecular dehydrationalcohols- splitting off a water molecule from two alcohol molecules when heated in the presence of water-removing agents:
As a result of intermolecular dehydration of alcohols, ethers. Thus, when ethyl alcohol is heated with sulfuric acid to a temperature of 100 to 140°C, diethyl (sulfur) ether is formed.
Interaction of alcohols with organic and inorganic acids with the formation of esters (esterification reaction)

The esterification reaction is catalyzed by strong inorganic acids. For example, when ethyl alcohol and acetic acid react, ethyl acetate is formed:
Intramolecular dehydration of alcohols occurs when alcohols are heated in the presence of water-removing agents to a higher temperature than the temperature of intermolecular dehydration. As a result, alkenes are formed. This reaction is due to the presence of a hydrogen atom and a hydroxyl group at adjacent carbon atoms. An example is the reaction of producing ethene (ethylene) by heating ethanol above 140°C in the presence of concentrated sulfuric acid:
Oxidation of alcohols usually carried out with strong oxidizing agents, for example, potassium dichromate or potassium permanganate in an acidic environment. In this case, the action of the oxidizing agent is directed to the carbon atom that is already bonded to the hydroxyl group. Depending on the nature of the alcohol and the reaction conditions, various products can be formed. So, primary alcohols are oxidized first to aldehydes, and then to carboxylic acids:
The oxidation of secondary alcohols produces ketones:

Tertiary alcohols are quite resistant to oxidation. However, under harsh conditions (strong oxidizing agent, heat) oxidation of tertiary alcohols is possible, which occurs with the rupture of carbon-carbon bonds closest to the hydroxyl group.
Dehydrogenation of alcohols. When alcohol vapor is passed at 200-300 °C over a metal catalyst, such as copper, silver or platinum, primary alcohols are converted into aldehydes, and secondary alcohols into ketones:
Qualitative reaction to polyhydric alcohols.
The presence of several hydroxyl groups in the alcohol molecule at the same time determines the specific properties of polyhydric alcohols, which are capable of forming bright blue complex compounds soluble in water when interacting with a freshly obtained precipitate of copper (II) hydroxide. For ethylene glycol we can write:

Monohydric alcohols are not able to enter into this reaction. Therefore, it is a qualitative reaction to polyhydric alcohols.

Preparation of alcohols:

Use of alcohols

methanol(methyl alcohol CH 3 OH) is a colorless liquid with a characteristic odor and a boiling point of 64.7 ° C. Burns with a slightly bluish flame. The historical name of methanol - wood alcohol is explained by one of the ways of its production by distilling hard wood (Greek methy - wine, get drunk; hule - substance, wood).

Methanol requires careful handling when working with it. Under the action of the enzyme alcohol dehydrogenase, it is converted in the body into formaldehyde and formic acid, which damage the retina of the eye, cause death of the optic nerve and total loss vision. Ingestion of more than 50 ml of methanol causes death.

Ethanol(ethyl alcohol C 2 H 5 OH) is a colorless liquid with a characteristic odor and a boiling point of 78.3 ° C. Flammable Mixes with water in any ratio. The concentration (strength) of alcohol is usually expressed as a percentage by volume. “Pure” (medicinal) alcohol is a product obtained from food raw materials and containing 96% (by volume) ethanol and 4% (by volume) water. To obtain anhydrous ethanol - “absolute alcohol”, this product is treated with substances that chemically bind water (calcium oxide, anhydrous copper (II) sulfate, etc.).

In order to make alcohol used for technical purposes unsuitable for drinking, small amounts of difficult-to-separate toxic, bad-smelling and disgusting-tasting substances are added to it and tinted. Alcohol containing such additives is called denatured or denatured alcohol.

Ethanol is widely used in industry to produce synthetic rubber, medicines, used as a solvent, included in varnishes and paints, perfumes. In medicine, ethyl alcohol is the most important disinfectant. Used for preparing alcoholic drinks.

When small amounts of ethyl alcohol enter the human body, they reduce pain sensitivity and block inhibition processes in the cerebral cortex, causing a state of intoxication. At this stage of the action of ethanol, water separation in the cells increases and, consequently, urine formation accelerates, resulting in dehydration of the body.

In addition, ethanol causes dilation of blood vessels. Increased blood flow in the skin capillaries leads to redness of the skin and a feeling of warmth.

IN large quantities ethanol inhibits brain activity (inhibition stage) and causes impaired coordination of movements. An intermediate product of ethanol oxidation in the body, acetaldehyde, is extremely toxic and causes severe poisoning.

Systematic consumption of ethyl alcohol and drinks containing it leads to a persistent decrease in brain productivity, death of liver cells and their replacement with connective tissue - liver cirrhosis.

Ethanediol-1,2(ethylene glycol) is a colorless viscous liquid. Poisonous. Unlimitedly soluble in water. Aqueous solutions do not crystallize at temperatures significantly below 0 °C, which makes it possible to use it as a component of non-freezing coolants - antifreeze for internal combustion engines.

Prolactriol-1,2,3(glycerin) is a viscous, syrupy liquid with a sweet taste. Unlimitedly soluble in water. Non-volatile. As a component of esters, it is found in fats and oils.

Widely used in cosmetics, pharmaceutical and food industries. In cosmetics, glycerin plays the role of an emollient and soothing agent. It is added to toothpaste to prevent it from drying out.

Glycerin is added to confectionery products to prevent their crystallization. It is sprayed onto tobacco, in which case it acts as a humectant that prevents the tobacco leaves from drying out and crumbling before processing. It is added to adhesives to prevent them from drying out too quickly, and to plastics, especially cellophane. In the latter case, glycerin acts as a plasticizer, acting like a lubricant between polymer molecules and thus giving plastics the necessary flexibility and elasticity.

Municipal budgetary educational institution

"Novoshimkussk secondary school

Yalchik district of the Chuvash Republic"

Abstract open lesson in chemistry
in 10th grade

« Structure of saturated monohydric alcohols.

Isomerism and nomenclature»

Prepared by a chemistry teacher

With. New Shimkus

Motto: To know the invisible,

Look carefully at what is visible.

(Ancient wisdom)

Target: Familiarization of students with the structure of saturated monohydric alcohols, isomerism and nomenclature , the influence of alcohols on a living organism.

Tasks:

educational:

developing:

educational

Equipment and reagents:

egg white

During the classes:

Organizing time. Repetition of the main classes of hydrocarbons - exercises, chemical dictation. Learning new material.

3.1. Setting the cognitive task of the lesson.

3.2. The concept of alcohols: composition and structure of alcohols.

3.3. Nomenclature of alcohols and classification of alcohols.

3.4. Isomerism of alcohols.

3.5. Group work.

3.6. Student presentation “The influence of ethanol on the human body.”

4. Fastening.

5.Reflection.

6.Homework par.20, exercise 5-7, page 88

1. Organizational moment.

2.Repetition of the composition and properties of hydrocarbons.

What hydrocarbons? we're talking about in riddles?

We are similar in properties to alkenes

We interact with bromine water we, too.
In molecules P-bonds are punishment,
Our suffix -in will tell you the name... (Alkins)

top class

Now let's do a little chemical dictation.

The teacher reads out the statement and may selectively ask any student to explain their answer. The dictation is conducted in writing, and students work in pairs. One of the students does the task at the board, the other works on the computer and takes the test.

1. The names have the suffix - an. (Alkanes)

2. They are characterized by sp2 hybridization of atomic orbitals. (Alkenes, dienes,)

3. Molecules contain only sigma bonds. (Alkanes, cycloalkanes)

4. There is one double bond in the molecules. (Alkenes)

5. There must be a cyclic fragment in the molecule. (Cycloalkanes)

6. They are characterized by sp-hybridization of atomic orbitals (Alkynes)

7. The general formula of these hydrocarbons is SpN2p. (Alkenes, cycloalkanes)

8.They are characterized mainly by substitution reactions. (Alkanes, cycloalkanes)

9. Molecules must have a triple bond. (Alkynes)

10. The names have the suffix –in (Alkynes)

o Select the structural formulas of homologues and isomers of butene-1 and give them names:

3. Setting the cognitive task of the lesson.

We are not simple substances
And known since ancient times.
Applicable in medicine:
Fight back the infection.
We are not so simple in properties,
And we are called... (alcohols)

So, the topic of our lesson today is

“Structure of saturated monohydric alcohols. Isomerism and nomenclature.”

Today we will get acquainted with the composition, structure, isomerism and nomenclature of these compounds. We will also find out what types of alcohols there are and what dangers may be hidden in the physical properties of alcohols.

4. Composition and structure of alcohols.

Task: The substance has been known to man since ancient times. Its name means Arabic“intoxicating.” It is widely applied in various fields National economy. Has disinfecting properties. What substance are we talking about if it is known that the combustion of 3.45 g of it produced 6.6 g of CO2 and water weighing 4.05 g? The vapor density of this substance in air is 1.59. (The answer is ethanol C2H5OH.)

The general formula of all monohydric alcohols is SpH2n + 1OH or ROH. Let's consider the structure of the alcohol molecule using the example of C2H5OH - ethyl alcohol.

One of the hydrogen atoms is different from the other atoms. (Question for students - Why?) It is connected to a carbon atom through oxygen. Therefore, it can be assumed that he will behave differently. What is this assumption based on? You can answer this question yourself, since you know that oxygen has a higher electronegativity. It will pull electrons from the hydrogen atom towards itself. O-H connection turns out to be polar. This is indicated by a directional arrow:

O  H. It is this group, OH, in alcohols that will determine their chemical properties, i.e., their chemical function. Such groups are called functional.

Functional is a group of atoms that determines the chemical properties of a substance.

What remains in the alcohol molecule after mental removal of the functional group is called a hydrocarbon radical.

Now we can derive the definition of alcohols... (formulated by the students themselves, suggest different variants determination of alcohols)

Alcohols are called organic matter, whose molecules contain one or more functional hydroxyl groups connected to a hydrocarbon radical.

Alcohols – these are derivatives of hydrocarbons, in the molecules of which one or more hydrogen atoms are replaced by functional (hydroxyl) groups.

Alcohols - This organic compounds, the molecules of which contain one or more hydroxyl groups connected to a hydrocarbon radical.

5.Nomenclature of alcohols .

Trivial nomenclature– the names of alcohols come from the names of radicals:

CH3OH – methyl alcohol. (C2H5OH, C3H7OH – they are called independently.)

Systematic nomenclature– the names of alcohols are formed from the names of saturated hydrocarbons by adding the suffix – ol:

CH3OH – methanol.

Basic principles of alcohol nomenclature:

The longest carbon chain is selected and numbered from the end of the chain closest to the hydroxo group. The substituents in the main carbon chain are named and their positions are indicated by numbers. Name the main chain as an alkane and add the suffix –ol. The number indicates the position of the OH group.

(Students complete the task on the nomenclature of alcohols, written on the board)

Task on the board: Name the alcohols using systematic nomenclature:

6. Classification of alcohols . ( CD of Cyril and Methodius )

(On the students’ desks is a classification scheme for alcohols)

Alcohols are classified in different ways.

alcohols are: limit unlimited aromatic

Alcohols are distinguished: monatomic diatomic triatomic

3. By the nature of the carbon atom. Depending on the valency of the alcohol group alcohols are: primary – contain a monovalent alcohol group –CH2OH (for example, CH3-CH2OH ethanol); secondary – contain a divalent alcohol group =CHOH (for example, CH3-CHOH-CH3 propanol-2); tertiary – contain a trivalent alcohol group =C-OH (for example, 2-methylbutanol-2:

(From the previously presented formulas, students find alcohols, formulas of alcohols of different classifications)

Exercise 1 . Which of the following alcohols are: a) primary; b) secondary; c) tertiary?

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Task 3.

(On the students’ desks is a diagram of the types of isomerism of alcohols; the concepts of “isomers” and “isomerism” are repeated.)

7. Isomerism of alcohols

The following types of isomerism are characteristic of alcohols:

Isomerism of the carbon skeleton

For example,

Interclass isomerism

For example,

Exercise:

8.Group work (5 groups working. Group 1 - builders create a ball-and-stick model of ethanol and methanol. Group 2 - practitioners, studying the physical properties of ethanol. Group 3 – theorists, using additional information, talk about methyl alcohol. Group 4 - theorists, using additional information, talks about ethyl alcohol. Group 5 – practitioners, studying the effect of ethanol on protein molecules) Each group answers the questions posed.

9. Student speech "The influence of ethanol on the human body."

4. Consolidation.

5. Reflection. What new did you learn from today's lesson? Where can you put your acquired knowledge into practice? Did you like our lesson? Why?

6. Homework. Par.20. ex. 5,6,7. Page 88.

C2H5OH is a drug. Under the influence of ethanol, a person’s attention is weakened, reactions are inhibited, and the correlation of movements is disrupted. Long-term use causes profound disorders nervous system, diseases of cardio-vascular system, digestive tract, a serious illness occurs - alcoholism.

Classification of alcohols.

1.By the nature of the hydrocarbon radical alcohols are: limit – hydrocarbon radical contains only single bonds (for example, CH3OH methanol, C4H9OH butanol); unlimited – contain an unsaturated hydrocarbon radical (for example, CH2=CH-CH2OH allyl alcohol); aromatic – contain an aromatic hydrocarbon radical (for example, C6H5-CH2OH benzyl alcohol).

2. By the number of hydroxyl groups alcohols are distinguished: monatomic – contain one OH group (for example, CH3-CH2-OH ethanol); diatomic – contain two OH groups (for example, HO-CH2-CH2-OH ethylene glycol or ethanediol-1,2); triatomic – contain three OH groups in the molecule (for example, HO-CH2-CHOH-CH2-OH glycerol or propanetriol-1,2,3).

Isomerism of the carbon skeleton

For example,

Functional group position isomerism

For example,

Interclass isomerism: Alcohols are isomers of ethers.

For example,

(Students complete the task of consolidation on separate cards.)

Exercise: Among the given formulas, find the isomers of pentanol-1 and determine the type of isomerism. Give names to all connections:

Task 3. Write all possible isomers of the substance C4H9OH.