These are derivatives of hydrocarbons in which one hydrogen atom is replaced by a hydroxy group. The general formula of alcohols is CnH 2 n +1 OH.

Classification of monohydric alcohols.

Depending on the position where it is located HE-group, distinguish:

Primary alcohols:

Secondary alcohols:

Tertiary alcohols:

.

Isomerism of monohydric alcohols.

For monohydric alcohols characterized by isomerism of the carbon skeleton and isomerism of the position of the hydroxy group.

Physical properties of monohydric alcohols.

The reaction follows Markovnikov’s rule, so only song alcohol can be obtained from primary alkenes.

2. Hydrolysis of alkyl halides under the influence of aqueous solutions of alkalis:

If the heating is weak, then intramolecular dehydration occurs, resulting in the formation of ethers:

B) Alcohols can react with hydrogen halides, with tertiary alcohols reacting very quickly, while primary and secondary alcohols react slowly:

The use of monohydric alcohols.

Alcohols used primarily in industrial organic synthesis, in the food industry, medicine and pharmacy.

Structure

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

Based on the number of hydroxyl groups (atomicity), alcohols are divided into:

Monatomic
dihydric (glycols)
triatomic.

The following alcohols are distinguished by their nature:

Saturated, containing only saturated hydrocarbon radicals in the molecule
unsaturated, containing multiple (double and triple) bonds between carbon atoms in the molecule
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.

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 therefore are classified as an independent class of organic compounds - phenols. For example, hydroxybenzene phenol. We will learn more about the structure, properties and use of phenols later.

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

It should be noted that alcohols containing two hydroxyl groups on one carbon atom are unstable and spontaneously decompose (subject to rearrangement of atoms) to form aldehydes and ketones:

Unsaturated alcohols containing a hydroxyl group at the carbon atom connected by a double bond are called ecols. It is not difficult to guess that the name of this class of compounds is formed from the suffixes -en and -ol, indicating the presence of a double bond and a hydroxyl group in the molecules. Enols, as a rule, are unstable and spontaneously transform (isomerize) into carbonyl compounds - aldehydes and ketones. This reaction is reversible, the process itself is called keto-enol tautomerism. Thus, the simplest enol, vinyl alcohol, isomerizes extremely quickly into acetaldehyde.

Based on the nature of the carbon atom to which the hydroxyl group is bonded, alcohols are divided into:

Primary, in the molecules of which the hydroxyl group is bonded to the primary carbon atom
secondary, in the molecules of which the hydroxyl group is bonded to a secondary carbon atom
tertiary, in the molecules of which the hydroxyl group is bonded to a tertiary carbon atom, for example:

Nomenclature and isomerism

When naming alcohols, the (generic) suffix -ol is added to the name of the hydrocarbon corresponding to the alcohol. The numbers after the suffix indicate the position of the hydroxyl group in the main chain, and the prefixes di-, tri-, tetra-, etc. indicate their number:

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.

Roda, which is part of the hydroxyl group of alcohol molecules, differs sharply from hydrogen and carbon atoms in its ability to attract and hold electron pairs. Due to this, alcohol molecules contain polar C-O and O-H bonds.

Physical properties of alcohols

Given the polarity of the O-H bond and the significant partial positive charge localized (focused) on the hydrogen atom, the hydrogen of the hydroxyl group is said to be “acidic” in nature. In this way, it differs sharply from the hydrogen atoms included in the hydrocarbon radical.

It should be noted that the oxygen atom of the hydroxyl group has a partial negative charge and two lone electron pairs, which allows alcohols to form special, so-called hydrogen bonds between molecules. Hydrogen bonds occur when a partially positively charged hydrogen atom of one alcohol molecule interacts with a partially negatively charged oxygen atom of another molecule. It is thanks to hydrogen bonds between molecules that alcohols have boiling points that are abnormally high for their molecular weight. Thus, propane with a relative molecular weight of 44 under normal conditions is a gas, and the simplest of alcohols is methanol, having a relative molecular weight of 32, under normal conditions a liquid.

The lower and middle members of a series of saturated monohydric alcohols, containing from one to eleven carbon atoms, are liquids. Higher alcohols (starting from C 12 H 25 OH) are solids at room temperature. Lower alcohols have a characteristic alcoholic odor and pungent taste; they are highly soluble in water. As the hydrocarbon radical increases, the solubility of alcohols in water decreases, and octanol no longer mixes with water.

Chemical properties

The properties of organic substances are determined by their composition and structure. Alcohols confirm the general rule. Their molecules include hydrocarbon and hydroxyl radicals, so the chemical properties of alcohols are determined by the interaction and influence of these groups on each other. The properties characteristic of this class of compounds are due to the presence of a hydroxyl group.

1. 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).

With water this interaction is much more active than with alcohol, is accompanied by a large release of heat, and can lead to an explosion. This difference is explained by the electron-donating properties of the radical closest to the hydroxyl group. Possessing the properties of an electron donor (+I-effect), the radical slightly increases the electron density on the oxygen atom, “saturates” it at its own expense, thereby reducing the polarity of the O-H bond and the “acidic” nature of the hydrogen atom of the hydroxyl group in alcohol molecules by compared to water molecules.

2. Interaction of alcohols with hydrogen halides. Substitution of a hydroxyl group with a halogen leads to the formation of haloalkanes.

For example:

C2H5OH + HBr<->C2H5Br + H2O

This reaction is reversible.

3. Intermolecular dehydration of alcohols - the splitting of 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 are formed. Thus, when ethyl alcohol is heated with sulfuric acid to a temperature of 100 to 140 ° C, diethyl (sulfur) ether is formed.

4. The interaction of alcohols with organic and inorganic acids to form esters (esterification reaction):

The esterification reaction is catalyzed by strong inorganic acids.

For example, the interaction of ethyl alcohol and acetic acid produces ethyl acetate - ethyl acetate:

5. 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.

6. Oxidation of alcohols is usually carried out with strong oxidizing agents, such as 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. Thus, primary alcohols are oxidized first to aldehydes and then to carboxylic acids:

Tertiary alcohols are quite resistant to oxidation. However, under harsh conditions (strong oxidizing agent, high temperature), oxidation of tertiary alcohols is possible, which occurs with the rupture of carbon-carbon bonds closest to the hydroxyl group.

7. 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:

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.

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

Alcoholates of alkali and alkaline earth metals undergo hydrolysis when interacting with water. For example, when sodium ethoxide is dissolved in water, a reversible reaction occurs

C2H5ONa + HON<->C2H5OH + NaOH

the balance of which is almost completely shifted to the right. This also confirms that water is superior to alcohols in its acidic properties (the “acidic” nature of the hydrogen in the hydroxyl group). Thus, the interaction of alcoholates with water can be considered as the interaction of a salt of a very weak acid (in this case, the alcohol that formed the alcoholate acts as this) with a stronger acid (water plays this role here).

Alcohols can exhibit basic properties when reacting with strong acids, forming alkyloxonium salts due to the presence of a lone electron pair on the oxygen atom of the hydroxyl group:

The esterification reaction is reversible (the reverse reaction is ester hydrolysis), the equilibrium shifts to the right in the presence of water-removing agents.

Intramolecular dehydration of alcohols proceeds in accordance with Zaitsev's rule: when water is removed from a secondary or tertiary alcohol, a hydrogen atom is detached from the least hydrogenated carbon atom. Thus, dehydration of 2-butanol results in 2-butene rather than 1-butene.

The presence of hydrocarbon radicals in the molecules of alcohols cannot but affect the chemical properties of alcohols.

The chemical properties of alcohols caused by the hydrocarbon radical are different and depend on its nature. So, all alcohols burn; unsaturated alcohols containing a double C=C bond in the molecule enter into addition reactions, undergo hydrogenation, add hydrogen, react with halogens, for example, decolorize bromine water, etc.

Methods of obtaining

1. Hydrolysis of haloalkanes. You already know that the formation of haloalkanes when alcohols interact with hydrogen halogens is a reversible reaction. Therefore, it is clear that alcohols can be obtained by hydrolysis of haloalkanes - the reaction of these compounds with water.

Polyhydric alcohols can be obtained by hydrolysis of haloalkanes containing more than one halogen atom per molecule.

2. Hydration of alkenes - the addition of water at the tg bond of an alkene molecule - is already familiar to you. Hydration of propene leads, in accordance with Markovnikov’s rule, to the formation of a secondary alcohol - propanol-2

HE
l
CH2=CH-CH3 + H20 -> CH3-CH-CH3
propene propanol-2

3. Hydrogenation of aldehydes and ketones. You already know that the oxidation of alcohols under mild conditions leads to the formation of aldehydes or ketones. It is obvious that alcohols can be obtained by hydrogenation (reduction with hydrogen, addition of hydrogen) of aldehydes and ketones.

4. Oxidation of alkenes. Glycols, as already noted, can be obtained by oxidation of alkenes with an aqueous solution of potassium permanganate. For example, ethylene glycol (ethanediol-1,2) is formed by the oxidation of ethylene (ethene).

5. Specific methods for producing alcohols. Some alcohols are obtained using methods that are unique to them. Thus, methanol is produced industrially by the interaction of hydrogen with carbon monoxide (II) (carbon monoxide) at elevated pressure and high temperature on the surface of a catalyst (zinc oxide).

The mixture of carbon monoxide and hydrogen required for this reaction, also called (think about why!) “synthesis gas,” is obtained by passing water vapor over hot coal.

6. Fermentation of glucose. This method of producing ethyl (wine) alcohol has been known to man since ancient times.

Let's consider the reaction of producing alcohols from haloalkanes - the hydrolysis reaction of halogenated hydrocarbons. It is usually carried out in an alkaline environment. The released hydrobromic acid is neutralized, and the reaction proceeds almost to completion.

This reaction, like many others, proceeds through the mechanism of nucleophilic substitution.

These are reactions the main stage of which is substitution, which occurs under the influence of a nucleophilic particle.

Let us recall that a nucleophilic particle is a molecule or ion that has a lone electron pair and is capable of being attracted to a “positive charge” - regions of the molecule with a reduced electron density.

The most common nucleophilic species are ammonia, water, alcohol, or anions (hydroxyl, halide, alkoxide ion).

The particle (atom or group of atoms) that is replaced by a reaction with a nucleophile is called a leaving group.

The replacement of the hydroxyl group of an alcohol with a halide ion also occurs through the mechanism of nucleophilic substitution:

CH3CH2OH + HBr -> CH3CH2Br + H20

Interestingly, this reaction begins with the addition of a hydrogen cation to the oxygen atom contained in the hydroxyl group:

CH3CH2-OH + H+ -> CH3CH2- OH

Under the influence of an attached positively charged ion, the C-O bond shifts even more towards oxygen, and the effective positive charge on the carbon atom increases.

This leads to the fact that nucleophilic substitution with a halide ion occurs much more easily, and a water molecule is split off under the action of the nucleophile.

CH3CH2-OH+ + Br -> CH3CH2Br + H2O

Preparation of ethers

When sodium alkoxide reacts with bromoethane, the bromine atom is replaced by an alkoxide ion and an ether is formed.

The nucleophilic substitution reaction in general can be written as follows:

R - X +HNu -> R - Nu +HX,

if the nucleophilic particle is a molecule (HBr, H20, CH3CH2OH, NH3, CH3CH2NH2),

R-X + Nu - -> R-Nu + X - ,

if the nucleophile is an anion (OH, Br-, CH3CH2O -), where X is a halogen, Nu is a nucleophilic particle.

Individual representatives of alcohols and their significance

Methanol (methyl alcohol CH3OH) 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 methods of its production - distillation of hard wood (Greek - wine, to get drunk; substance, wood).

Methanol is very poisonous! It 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, cause death of the optic nerve and complete loss of vision. Ingestion of more than 50 ml of methanol causes death.

Ethanol (ethyl alcohol C2H5OH) 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 for the production of synthetic rubber, medicines, is used as a solvent, is part of varnishes and paints, and 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.

Propanetriol-1,2,3 (glycerol) 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.

1. What substances are called alcohols? By what criteria are alcohols classified? What alcohols should be classified as butanol-2? butene-Z-ol-1? penten-4-diol-1,2?

2. Write down the structural formulas of the alcohols listed in Exercise 1.

3. Are there quaternary alcohols? Explain your answer.

4. How many alcohols have the molecular formula C5H120? Make up the structural formulas of these substances and name them. Can this formula only correspond to alcohols? Make up the structural formulas of two substances that have the formula C5H120 and are not alcohols.

5. Name the substances whose structural formulas are given below:

6. Write the structural and empirical formulas of a substance whose name is 5-methyl-4-hexen-1-inol-3. Compare the number of hydrogen atoms in the molecule of this alcohol with the number of hydrogen atoms in the molecule of an alkane with the same number of carbon atoms. What explains this difference?

7. Comparing the electronegativity of carbon and hydrogen, explain why the O-H covalent bond is more polar than the C-O bond.

8. Which alcohol do you think - methanol or 2-methylpropanol-2 - will react more actively with sodium? Explain your answer. Write down equations for the corresponding reactions.

9. Write down reaction equations for the interaction of 2-propanol (isopropyl alcohol) with sodium and hydrogen bromide. Name the reaction products and indicate the conditions for their implementation.

10. A mixture of propanol-1 and propanol-2 vapors was passed over heated copper(P) oxide. What reactions could occur in this case? Write down equations for these reactions. What classes of organic compounds do their products belong to?

11. What products can be formed during the hydrolysis of 1,2-dichloropropanol? Write down equations for the corresponding reactions. Name the products of these reactions.

12. Write down equations for the reactions of hydrogenation, hydration, halogenation and hydrohalogenation of 2-propenol-1. Name the products of all reactions.

13. Write down equations for the interaction of glycerol with one, two and three moles of acetic acid. Write the equation for the hydrolysis of an ester - the product of the esterification of one mole of glycerol and three moles of acetic acid.

14*. When the primary saturated monohydric alcohol reacted with sodium, 8.96 liters of gas (n.e.) were released. When the same mass of alcohol is dehydrated, an alkene weighing 56 g is formed. Determine all possible structural formulas of the alcohol.

15*. The volume of carbon dioxide released during the combustion of saturated monohydric alcohol is 8 times greater than the volume of hydrogen released by the action of excess sodium on the same amount of alcohol. Establish the structure of an alcohol if it is known that its oxidation produces a ketone.

Use of alcohols

Since alcohols have various properties, their area of ​​application is quite wide. Let's try to figure out where alcohols are used.

Alcohols in the food industry

Alcohol such as ethanol is the basis of all alcoholic beverages. And it is obtained from raw materials that contain sugar and starch. Such raw materials can be sugar beets, potatoes, grapes, as well as various cereals. Thanks to modern technologies, during the production of alcohol, it is purified from fusel oils.

Natural vinegar also contains ethanol-based raw materials. This product is obtained through oxidation by acetic acid bacteria and aeration.

But in the food industry they use not only ethanol, but also glycerin. This food additive promotes the connection of immiscible liquids. Glycerin, which is part of liqueurs, can give them viscosity and a sweet taste.

Also, glycerin is used in the manufacture of bakery, pasta and confectionery products.

Medicine

In medicine, ethanol is simply irreplaceable. In this industry, it is widely used as an antiseptic, as it has properties that can destroy microbes, delay painful changes in the blood and prevent decomposition in open wounds.

Ethanol is used by medical workers before performing various procedures. This alcohol has disinfecting and drying properties. During artificial ventilation of the lungs, ethanol acts as an antifoam. Ethanol can also be one of the components of anesthesia.

When you have a cold, ethanol can be used as a warming compress, and when cooling, as a rubbing agent, since its substances help restore the body during heat and chills.

In case of poisoning with ethylene glycol or methanol, the use of ethanol helps reduce the concentration of toxic substances and acts as an antidote.

Alcohols also play a huge role in pharmacology, as they are used to prepare healing tinctures and all kinds of extracts.

Alcohols in cosmetics and perfumes

In perfumery, it is also impossible to do without alcohol, since the basis of almost all perfume products is water, alcohol and perfume concentrate. Ethanol in this case acts as a solvent for fragrant substances. But 2-phenylethanol has a floral scent and can replace natural rose oil in perfumery. It is used in the manufacture of lotions, creams, etc.

Glycerin is also the base for many cosmetics, as it has the ability to attract moisture and actively moisturize the skin. And the presence of ethanol in shampoos and conditioners helps moisturize the skin and makes it easier to comb hair after washing your hair.

Fuel

Well, alcohol-containing substances such as methanol, ethanol and butanol-1 are widely used as fuel.

Thanks to the processing of plant materials such as sugar cane and corn, it was possible to obtain bioethanol, which is an environmentally friendly biofuel.

Recently, the production of bioethanol has become popular in the world. With its help, the prospect of renewing fuel resources appeared.

Solvents, surfactants

In addition to the applications of alcohols already listed, it can be noted that they are also good solvents. The most popular in this area are isopropanol, ethanol, and methanol. They are also used in the production of bit chemicals. Without them, proper care of a car, clothing, household utensils, etc. is not possible.

The use of alcohols in various areas of our activities has a positive effect on our economy and brings comfort to our lives.

Goals:

Educational: familiarize students with the classification of alcohols, their nomenclature and isomerism. Consider the influence of the structure of alcohols on their properties. Developmental: Strengthen skills of working in groups, develop skills for finding relationships between new and studied material. Educational: developing teamwork skills Student - student, Student - teacher. Be able to analyze the information received.

Lesson type: Combined

Organizational form: frontal survey, laboratory work, independent work, conversation on problematic issues, analysis of the information received.

Equipment:

1. Set of slides ( Annex 1) tables, individual sheets with tasks for independent work, tasks for laboratory work.
2. On student tables: bottles with alcohols (ethyl, isopropyl, glycerin), sodium, copper oxide (2), acetic acid, phenolphthalein, potassium permanganate, sand, sodium hydroxide, hydrochloric acid, tap water, chemical glassware, safety regulations .

Lesson plan:

1. 1.Definition of the class of alcohols, the structure of the molecule of monohydric saturated alcohols.
2. Classification of alcohols according to three criteria.
3. Nomenclature of alcohols.
4. Types of isomerism of monohydric saturated alcohols.
5. Physical properties of alcohols. The influence of hydrogen bonding on the physical properties of alcohols.

2. 6.Chemical properties.
7. Consolidation of new material.

DURING THE CLASSES

I. Organizational moment

Teacher: We have completed the study of a large class of organic compounds consisting of only two chemical elements - carbon and hydrogen. What other chemical elements are most often found in organic compounds?

Student: Oxygen, nitrogen, phosphorus, sulfur and others.

II. Learning new material

Teacher: We are beginning to study a new class of organic compounds, which, in addition to carbon and hydrogen, include oxygen. They are called oxygen-containing. (Slide No. 1).
As we see, there are several classes of organic compounds consisting of carbon, hydrogen and oxygen. Today we are starting to study a class called “Alcohols”. Alcohol molecules contain a hydroxyl group, which is the functional group (FG) for this class. What do we call FG? (Slide No. 1).

Student: A group of atoms (or an atom) that determines whether a compound belongs to a certain class and determines its most important chemical properties is called a FG.

Teacher: Alcohols are a large class of organic compounds in terms of diversity and properties that are widely used in various areas of the national economy. (Slides No. 2-8)
As we see, this is pharmaceuticals, cosmetics production, food industry, and also as a solvent in the production of plastics, varnishes, paints, etc. Let's look at the table.

Table 1.

SOME IMPORTANT REPRESENTATIVES OF THE CLASS OF ALCOHOLS

Teacher: If we talk about the effect on the human body, then all alcohols are poisons. Alcohol molecules have a detrimental effect on living cells. (Slide No. 9) Spit - alkanes have an outdated name for alcohol. Alcohols are derivatives of hydrocarbons in which one or more hydrogen atoms are replaced by hydroxyl groups - OH.
In the simplest case, the structure of alcohol can be expressed by the following formula:

R–OH,

where R is a hydrocarbon radical.

Alcohols can be classified according to three criteria:

1. The number of hydroxyl groups (monoatomic, diatomic, polyatomic).

Table 2.

CLASSIFICATION OF ALCOHOLS ACCORDING TO THE NUMBER OF HYDROXYL GROUPS (–OH)

2. The nature of the hydrocarbon radical (saturated, unsaturated, aromatic).

Table 3.

CLASSIFICATION OF ALCOHOLS BY NATURE OF RADICAL

3. The nature of the carbon atom to which the hydroxyl group is connected (primary, secondary, tertiary)

Table 4.

CLASSIFICATION OF ALCOHOLS BY THE CHARACTER OF THE CARBON ATOM ASSOCIATED WITH THE FUNCTIONAL GROUP –OH

There are no quaternary alcohols because the quaternary C atom is bonded to 4 other C atoms, so there are no more valences to bind to the hydroxyl group.

Let's consider the basic principles of constructing the names of alcohols according to the substitutive nomenclature, using the scheme:

Name of alcohol = name HC + (prefix) + - OL +(n1, n2 ..., nn), where prefix denotes the number of –OH groups in the molecule: 2 – “di”, 3 – “three”, 4 – “tetra”, etc.
n indicates the position of hydroxyl groups in the carbon chain, for example:

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

In our school course we will study in detail monohydric saturated alcohols with the general formula: CnH2n+1OH

Let's consider models of molecules of individual representatives of these alcohols (methyl, ethyl, glycerol). (Slides No. 10-13)

Homologous series of these alcohols starts with methyl alcohol:

CH3 – OH – methyl alcohol
CH3 – CH2 – OH – ethyl alcohol
CH3 – CH2 – CH2 – OH – propyl alcohol
CH3 – CH2 – CH2 – CH2 – OH – butyl alcohol
CH3 – CH2 – CH2 – CH2 – CH2 – OH – amyl alcohol or pentanol

Isomerism

The following are characteristic of saturated monohydric alcohols: types of isomerism:

1) positions of functional groups

2) carbon skeleton.

Please note– numbering of carbon atoms begins from the end close to the –OH group.

3) interclass isomerism (with ethers R – O – R)

Physical properties of alcohols

The first ten members of the homologous series of representatives of monohydric alcohols are liquids, higher alcohols are solids. (Slides 14, 15)
The hydrogen bond formed between alcohol molecules has a strong influence on the physical properties of alcohols. You are familiar with hydrogen bonding from the 9th grade program, topic “Ammonia”. Now your classmate, who received an individual assignment in the last lesson, will remind us what a hydrogen bond is.

Student answer

A hydrogen bond is a bond between the hydrogen atoms of one molecule and the highly electronegative atoms of another molecule. (F, O, N, CL). On the letter it is indicated by three dots. (Slides 16,17). A hydrogen bond is a special type of intermolecular bond, which is 10-20 times weaker than a regular covalent bond, but it has a great influence on the physical properties of compounds.
Two consequences of hydrogen bonding: 1) good solubility of substances in water; 2) increase in melting and boiling points. For example: the dependence of the boiling point of some compounds on the presence of a hydrogen bond.

Teacher: What conclusions can we draw about the effect of hydrogen bonding on the physical properties of alcohols?

Students: 1) In the presence of a hydrogen bond, the boiling point increases greatly.
2) The higher the atomicity of the alcohol, the more hydrogen bonds are formed.

This also helps to increase the boiling point.

CHEMICAL PROPERTIES OF ALCOHOLS

(Repeat PTB)

Burning of alcohols.

2. Interaction of alcohols with alkali metals.

3. Oxidation of alcohols (qualitative reaction) - production of aldehydes.

4. The interaction of alcohols with acids to form esters (esterification reaction).

5. Intramolecular dehydration of alcohols with the formation of unsaturated hydrocarbons.

6. Intermolecular dehydration of alcohols to form ethers.

7. Dehydrogenation of alcohols - obtaining aldehydes.

Teacher: write a five-line poem (Cinquain)

1st keyword

2nd two adjectives

3rd three verbs

4th sentence

5th word associated with the keyword.

Student. Alcohols.

Poisonous, liquid

They strike, they destroy, they destroy

They have a narcotic effect on the human body.

Drugs.

IV. Homework: paragraph No. 9, pp. 66-70 ex. No. 13 b.

Individual tasks. Using additional literature: 1) talk about the areas of application of glycerin and ethylene glycol; 2) talk about the production of alcohols from cellulose and fats; 3) how do these alcohols act on the human body?

V. Lesson summary Let's sum it up in the form of doing independent work in two options

Literature:

1. Chemistry 10th grade. Textbook for general education institutions. Bustard Moscow 2008. Basic level. 4th ed. stereotypical.
2. Chemistry 100 class workbook for the textbook. A basic level of. Bustard, 2007.
3. Lesson developments in chemistry. To the textbooks of O. S. Gabrielyan, . Grade 10
4. , . Chemistry 9th grade Smolensk Association XXI century 2006
5. . CHEMISTRY. New school aid for applicants to universities. Ed. 4th, corrected and supplemented. Rostov-on-Don. Phoenix 2007.

Intoxicating drinks, which contain ethanol - monohydric wine alcohol, have been familiar to mankind since ancient times. They were made from honey and fermented fruits. In ancient China, rice was also added to drinks.

Alcohol from wine was obtained in the East (VI-VII centuries). European scientists created it from fermentation products in the 11th century. The Russian royal court became acquainted with it in the 14th century: the Genoese embassy presented it as living water (“aqua vita”).

THOSE. Lovitz, a Russian scientist of the 18th century, was the first to experimentally obtain absolute ethyl alcohol by distillation using potash - potassium carbonate. The chemist suggested using charcoal for cleaning.

Thanks to the scientific achievements of the 19th and 20th centuries. The global use of alcohols became possible. Scientists of the past developed a theory of the structure of aqueous-alcohol solutions and studied their physicochemical properties. Fermentation methods were discovered: cyclic and continuous flow.

Significant inventions of chemical science of the past, which made the beneficial properties of alcohols real:

• Barbe ratification apparatus (1881)
• Saval's distillation plate apparatus (1813)
• Gentse's boiler (1873)

A homologous series of alcoholic substances was discovered. A series of experiments on the synthesis of methanol and ethylene glycol were carried out. Advanced scientific research in the post-war years of the 20th century helped improve the quality of products. We raised the level of the domestic alcohol industry.

Distribution in nature

In nature, alcohols occur in free form. The substances are also components of esters. The natural fermentation process of carbohydrate-containing foods creates ethanol, as well as 1-butanol and isopropanol. Alcohols in the baking industry, brewing, and winemaking are associated with the use of the fermentation process in these industries. Most insect pheromones are alcohols.

Alcohol derivatives of carbohydrates in nature:

• sorbitol - found in rowan and cherry berries, has a sweet taste.

Many plant aromatic substances are terpene alcohols:

• fenhol - a component of fennel fruits, coniferous tree resins
• borneol - a constituent element of the wood of the borneocamphor tree
• menthol is a component of geranium and mint composition

Bile of humans and animals contains bile polyhydric alcohols:

• mixinol
• chimerol
• bufol
• cholestanpentol

Harmful effects on the body

The widespread use of alcohols in agriculture, industry, military affairs, and transport makes them accessible to ordinary citizens. This causes acute, including mass, poisonings and deaths.

The dangers of methanol

Methanol is a dangerous poison. It has a toxic effect on the heart and nervous system. Ingestion of 30 g of methanol leads to death. Ingestion of a smaller amount of the substance causes severe poisoning with irreversible consequences (blindness).

Its maximum permissible concentration in the air at work is 5 mg/m³. Liquids containing even a minimal amount of methanol are dangerous.

In mild forms of poisoning, symptoms appear:

• chills
• general weakness
• nausea
• headache

Methanol tastes and smells no different from ethanol. This causes the poison to be ingested by mistake. How to distinguish ethanol from methanol at home?

Copper wire is rolled into a spiral and heated strongly over a fire. When it interacts with ethanol, the smell of rotten apples is felt. Contact with methanol will trigger an oxidation reaction. Formaldehyde will be released - a gas with an unpleasant, pungent odor.

Ethanol toxicity

Ethanol acquires toxic and narcotic properties depending on the dose, route of entry into the body, concentration, and duration of exposure.

Ethanol can cause:

• disruption of the central nervous system
• cancer of the esophagus, stomach
• gastritis
• cirrhosis of the liver
• heart diseases

4-12 g of ethanol per 1 kg of body weight is a lethal single dose. Acetaldehyde, the main metabolite of ethanol, is a carcinogenic, mutagenic, toxic substance. It changes cell membranes, the structural characteristics of red blood cells, and damages DNA. Isopropanol is similar to ethanol in toxic effects.

The production of alcohols and their circulation are regulated by the state. Ethanol is not legally recognized as a drug. But its toxic effects on the body have been proven.

The effect on the brain is especially destructive. Its volume decreases. Organic changes occur in the neurons of the cerebral cortex, their damage and death. Capillary ruptures occur.

The normal functioning of the stomach, liver, and intestines is disrupted. Excessive consumption of strong alcohol causes acute pain and diarrhea. The mucous membrane of the gastrointestinal tract is damaged, and bile stagnates.

Inhalation effects of alcohols

The widespread use of alcohols in many industries creates a threat of their inhalation effects. Toxic effects were studied in rats. The results obtained are shown in the table.

Food industry

Ethanol is the basis of alcoholic beverages. It is obtained from sugar beets, potatoes, grapes, cereals - rye, wheat, barley, and other raw materials containing sugar or starch. During the production process, modern technologies for purifying fusel oils are used.

They are divided into:

• strong with an ethanol share of 31-70% (cognac, absinthe, rum, vodka)
• medium strength - from 9 to 30% ethanol (liqueurs, wines, liqueurs)
• low alcohol - 1.5-8% (cider, beer).

Ethanol is the raw material for natural vinegar. The product is obtained by oxidation with acetic acid bacteria. Aeration (forced saturation with air) is a necessary condition for the process.

Ethanol is not the only alcohol in the food industry. Glycerin - food additive E422 - provides the connection of immiscible liquids. It is used in the manufacture of confectionery, pasta, and bakery products. Glycerin is a component of liqueurs, giving drinks a viscosity and sweet taste.

The use of glycerin has a beneficial effect on products:

• Pasta stickiness decreases
• the consistency of sweets and creams improves
• prevents rapid staleness of bread and sagging of chocolate
• Products are baked without starch sticking

The use of alcohols as sweeteners is common. Mannitol, xylitol, and sorbitol are suitable for this purpose.

Perfumes and cosmetics

Water, alcohol, perfume composition (concentrate) are the main components of perfume products. They are used in different proportions. The table presents the types of perfumes and the proportions of the main components.

In the production of perfumery products, highly purified ethanol acts as a solvent for fragrant substances. When reacting with water, salts are formed which precipitate. The solution settles for several days and is filtered.

2-phenylethanol replaces natural rose oil in the perfume and cosmetics industry. The liquid has a light floral scent. Included in fantasy and flower compositions, cosmetic milks, creams, elixirs, lotions.

The main base of many care products is glycerin. It is able to attract moisture, actively moisturize the skin, and make it elastic. Dry, dehydrated skin benefits from creams, masks, and soaps with glycerin: it creates a moisture-saving film on the surface and keeps the skin soft.

There is a myth: that using alcohol in cosmetics is harmful. However, these organic compounds are stabilizers, carriers of active substances, and emulsifiers necessary for the production of products.

Alcohols (especially fatty ones) make care products creamy and soften skin and hair. Ethanol in shampoos and conditioners moisturizes, evaporates quickly after washing your hair, and makes combing and styling easier.

Medicine

Ethanol is used in medical practice as an antiseptic. It destroys microbes, prevents decomposition in open wounds, and delays painful changes in the blood.

Its drying, disinfecting, tanning properties are the reason for using it to treat the hands of medical personnel before working with a patient. During artificial ventilation, ethanol is indispensable as an antifoam. If there is a shortage of medications, it becomes a component of general anesthesia.

In case of poisoning with ethylene glycol or methanol, ethanol becomes an antidote. After taking it, the concentration of toxic substances decreases. Ethanol is used in warming compresses and when rubbing for cooling. The substance restores the body during feverish heat and colds.

Alcohols in medicines and their effects on humans are studied by the science of pharmacology. Ethanol as a solvent is used in the production of extracts and tinctures of medicinal plant materials (hawthorn, pepper, ginseng, motherwort).

These liquid medicines should only be taken after medical advice. You must strictly follow the dosage prescribed by your doctor!

Fuel

The commercial availability of methanol, butanol-1, ethanol is the reason for their use as fuel. Mixed with diesel fuel, gasoline, used as fuel in its pure form. The mixtures help reduce the toxicity of exhaust gases.

Alcohol, as an alternative source of fuel, has its disadvantages:

• substances have increased corrosive characteristics, unlike hydrocarbons
• If moisture gets into the fuel system, there will be a sharp decrease in power due to the solubility of substances in water
• there is a risk of vapor locks and deterioration of engine performance due to low boiling points of substances.

However, gas and oil resources are finite. Therefore, the use of alcohols in world practice has become an alternative to the use of conventional fuel. Their mass production is being established from industrial waste (pulp and paper, food, woodworking) - at the same time the problem of recycling is being solved.

Industrial processing of plant raw materials makes it possible to obtain environmentally friendly biofuel - bioethanol. The raw materials for it are corn (USA), sugar cane (Brazil).

The positive energy balance and renewable fuel resource make bioethanol production a popular area of ​​the global economy.

Solvents, surfactants

In addition to the production of cosmetics, perfumes, liquid medicines, and confectionery, alcohols are also good solvents:

Alcohol as a solvent:

• in the manufacture of metal surfaces, electronic elements, photographic paper, photographic films
• when cleaning natural products: resins, oils, waxes, fats
• in the process of extraction - extracting a substance
• when creating synthetic polymeric materials (glue, varnish), paints
• in the production of medical and household aerosols.

Popular solvents are isopropanol, ethanol, methanol. Polyhydric and cyclic substances are also used: glycerin, cyclohexanol, ethylene glycol.

Surfactants are produced from higher fatty alcohols. Complete care of your car, dishes, apartments, and clothes is possible thanks to surfactants. They are part of cleaning products and detergents and are used in many sectors of the economy (see table).

Industry	Surfactants: functions, properties
Agriculture	Included in emulsions; increase the productivity of the process of transferring nutrients to plants
Construction	Reduce water demand for concrete and cement mixtures; increase frost resistance and density of materials
Leather industry	Prevents sticking and damage to products
Textile industry	Remove static electricity
Metallurgy	Reduce friction; able to withstand high temperatures
Paper industry	Separate boiled pulp from ink during used paper recycling
Paint industry	Enables complete penetration of paint onto surfaces, including small recesses

The use of alcohols in the food industry, medicine, the production of perfumes and cosmetics, use as fuel, solvents, and surfactants has a positive effect on the state of the country’s economy. It brings convenience to a person’s life, but requires compliance with safety precautions due to the toxicity of the substances.

Which contain one or more hydroxyl groups. Depending on the number of OH groups, these are divided into monohydric alcohols, trihydric alcohols, etc. Most often, these complex substances are considered as derivatives of hydrocarbons, the molecules of which have undergone changes, because one or more hydrogen atoms have been replaced by a hydroxyl group.

The simplest representatives of this class are monohydric alcohols, the general formula of which looks like this: R-OH or

Cn+H 2n+1OH.

1. Alcohols containing up to 15 carbon atoms are liquids, 15 or more are solids.
2. Solubility in water depends on the molecular weight; the higher it is, the less soluble the alcohol is in water. Thus, lower alcohols (up to propanol) are mixed with water in any proportions, while higher alcohols are practically insoluble in it.
3. The boiling point also increases with increasing atomic mass, for example, t bp. CH3OH = 65 °C, and boiling point. C2H5OH =78 °C.
4. The higher the boiling point, the lower the volatility, i.e. the substance does not evaporate well.

These physical properties of saturated alcohols with one hydroxyl group can be explained by the occurrence of intermolecular hydrogen bonds between individual molecules of the compound itself or the alcohol and water.

Monohydric alcohols are capable of entering into the following chemical reactions:

Having examined the chemical properties of alcohols, we can conclude that monohydric alcohols are amphoteric compounds, because they can react with alkali metals, exhibiting weak properties, and with hydrogen halides, exhibiting basic properties. All chemical reactions involve breaking the O-H or C-O bond.

Thus, saturated monohydric alcohols are complex compounds with one OH group that do not have free valencies after the formation of the C-C bond and exhibit weak properties of both acids and bases. Due to their physical and chemical properties, they are widely used in organic synthesis, in the production of solvents, fuel additives, as well as in the food industry, medicine, and cosmetology (ethanol).