General formulas of oxygen-containing substances.

METHODOLOGICAL DEVELOPMENT

For a lecture

in the discipline "Chemistry"

for cadets of the 2nd course in the specialty 280705.65 -

"Fire safety"

SECTION IV

PHYSICO-CHEMICAL PROPERTIES OF ORGANIC SUBSTANCES

TOPIC 4.16

SESSION № 4.16.1-4.16.2

OXYGEN-CONTAINING ORGANIC COMPOUNDS

Discussed at the PMC meeting

protocol No. ____ dated "___" _______ 2015

Vladivostok

I. Goals and objectives

Training: give a definition of oxygen-containing organic compounds, draw the attention of cadets to their diversity and prevalence. Show the dependence of physico-chemical and flammable properties oxygen-containing organic compounds on their chemical structure.

Educational: to educate students in the responsibility for preparing for practical activities.

II. Calculation of study time

III. Literature

1. Glinka N.L. general chemistry. – Tutorial for universities / Ed. A.I. Ermakov. - ed.30, corrected. - M.: Integral-Press, 2010. - 728 p.

2. Svidzinskaya G.B. Laboratory work on organic chemistry: Tutorial. - St. Petersburg: SPbI GPS EMERCOM of Russia, 2003. - 48p.

IV. Educational and material support

1. Technical means training: TV, graphic projector, video recorder, DVD-player, computer equipment, interactive whiteboard.

2. Periodic system of elements D.I. Mendeleev, demonstration posters, diagrams.

V. Text of the lecture

INTRODUCTION (5 min.)

The teacher checks the presence of students (cadets), announces the topic, learning goals and questions of the lesson.

MAIN PART (170 min)

Question No. 1. Classification of oxygen-containing organic compounds (20 min).

All these substances (like most organic substances) in accordance with Technical regulation on fire safety requirements. Federal Law No. 123-FZ refer to substances that can form an explosive mixture (a mixture of air and an oxidizer with combustible gases or vapors of flammable liquids), which, at a certain concentration, can explode (Article 2. P.4). This is what determines the fire and explosion hazard of substances and materials, i.e. their ability to form a combustible environment, characterized by their physico-chemical properties and (or) behavior in fire conditions (P.29) .

Properties of this type compounds are due to the presence of functional groups.

Functional group	Name of the functional group	Connection class	Connection examples
DREAM	hydroxyl	Alcohols	CH 3 - CH 2 - OH
C=O	carbonyl	Aldehydes	CH 3 - C \u003d O ç H
Ketones	CH 3 - C - CH 3 ll O
- C \u003d O ç OH	carboxyl	carboxylic acids	CH 3 - C \u003d O ç OH
C - O - C		ethers	CH 3 - O - CH 2 - CH 3
C - C \u003d O ç O - C		esters	C 2 H 5 - C \u003d O ç O - CH 3
C - O - O - C		peroxide compounds	CH 3 - O - O - CH 3

It is easy to see that all classes oxygenated compounds can be considered as hydrocarbon oxidation products. In alcohols, only one of the four carbon atom valences is used for connection with an oxygen atom, and therefore alcohols are the least oxidized compounds. More oxidized compounds are aldehydes and ketones: their carbon atom has two bonds with oxygen. The most oxidized carboxylic acids, because. in their molecules, the carbon atom used up its three valences per bond to the oxygen atom.

On carboxylic acids, the oxidation process is completed, leading to the formation of organic substances resistant to the action of oxidizing agents:

alcohol D aldehyde D carboxylic acid ® CO 2

Question number 2. Alcohols (40 min)

Alcohols - organic compounds whose molecules contain one or more hydroxyl groups (-OH) connected to hydrocarbon radicals.

Alcohol classification

I. Depending on the number of hydroxyl groups:

II. According to the saturation of the hydrocarbon radical:

III. By the nature of the hydrocarbon radical associated with the OH group:

Monohydric alcohols

General formula saturated monohydric alcohols: C n H 2 n +1 OH.

Nomenclature

Two possible names for the class of alcohols are used: "alcohols" (from the Latin "spiritus" - spirit) and "alcohols" (Arabic).

By international nomenclature the name of alcohols is formed from the name of the corresponding hydrocarbon with the addition of the suffix ol:

CH 3 OH methanol

C 2 H 5 OH ethanol, etc.

The main chain of carbon atoms is numbered from the end closest to which the hydroxyl group is located:

5 CH 3 - 4 CH - 3 CH 2 - 2 CH 2 - 1 CH 2 -OH

4-methylpentanol-2

Isomerism of alcohols

The structure of alcohols depends on the structure of the radical and the position of the functional group, i.e. in the homologous series of alcohols, there can be two types of isomerism: isomerism of the carbon skeleton and isomerism of the position of the functional group.

In addition, the third type of alcohol isomerism is interclass isomerism with ethers.

So, for example, for pentanols (general formula C 5 H 11 OH), all 3 indicated types of isomerism are characteristic:

1. Isomerism of the skeleton

pentanol-1

CH 3 - CH - CH 2 - CH 2 -OH

3-methylbutanol-1

CH 3 - CH 2 - CH - CH 2 -OH

2-methylbutanol-1

CH 3 - CH - CH 2 - OH

2,2-dimethylpropanol-1

The above isomers of pentanol, or amyl alcohol, are trivially called "fusel oils".

2. Isomerism of the position of the hydroxyl group

CH 3 - CH 2 - CH 2 - CH 2 - CH 2 - OH

pentanol-1

CH 3 - CH - CH 2 - CH 2 -CH 2

pentanol-2

CH 3 - CH 2 - CH - CH 2 -CH 2

pentanol-3

3. Interclass isomerism

C 2 H 5 - O - C 3 H 7

ethyl propyl ether

The number of isomers in the series of alcohols is growing rapidly: an alcohol with 5 carbon atoms has 8 isomers, with 6 carbon atoms - 17, with 7 carbon atoms - 39, and with 10 carbon atoms - 507.

Methods for obtaining alcohols

1. Obtaining methanol from synthesis gas

400 0 C, ZnO, Cr 2 O 3

CO + 2H 2 ¾¾¾¾¾® CH 3 OH

2. Hydrolysis of halocarbons (in aqueous solutions of alkalis):

CH 3 - CH - CH 3 + KOH water ® CH 3 - CH - CH 3 + KCl

2-chloropropane propanol-2

3. Hydration of alkenes. The reaction proceeds according to the rule of V.V. Markovnikov. The catalyst is dilute H 2 SO 4 .

CH 2 \u003d CH 2 + HOH ® CH 3 - CH 2 - OH

ethylene ethanol

CH 2 \u003d CH - CH 3 + HOH ® CH 2 - CH - CH 3

propene propanol-2

4. Recovery of carbonyl compounds (aldehydes and ketones).

When aldehydes are reduced, primary alcohols are obtained:

CH 3 - CH 2 - C \u003d O + H 2 ® CH 3 - CH 2 - CH 2 - OH

propanol-1 propanal

When ketones are reduced, secondary alcohols are obtained:

CH 3 - C - CH 3 + H 2 ® CH 3 - CH - CH 3

propanone (acetone) propanol-2

5. Obtaining ethanol by fermentation of sugary substances:

enzymes enzymes

C 12 H 22 O 11 + H 2 O ¾¾¾® 2C 6 H 12 O 6 ¾¾¾® 4C 2 H 5 OH + 4CO 2

sucrose glucose ethanol

enzymes enzymes

(C 6 H 10 O 5) n + H 2 O ¾¾¾® nC 6 H 12 O 6 ¾¾¾® C 2 H 5 OH + CO 2

cellulose glucose ethanol

Alcohol obtained by fermentation of cellulose is called hydrolysis alcohol and is used only for technical purposes, because contains a large amount harmful impurities: methanol, acetaldehyde and fusel oils.

6. Hydrolysis of esters

H + or OH -

CH 3 - C - O - CH 2 - CH 2 -CH 3 + H 2 O ¾¾® CH 3 - C - OH + OH - CH 2 - CH 2 -CH 3

acetic acid propyl ester acetic propanol-1

(propylethanoate) acid

7. Recovery of esters

CH 3 - C - O - CH 2 - CH 2 -CH 3 ¾¾® CH 3 - CH 2 - OH + OH - CH 2 - CH 2 -CH 3

propyl ester of acetic acid ethanol propanol-1

(propyl ethanoate)

Physical properties alcohols

Limit alcohols containing from 1 to 12 carbon atoms are liquids; from 13 to 20 carbon atoms - oily (ointment-like) substances; more than 21 carbon atoms solids.

Lower alcohols (methanol, ethanol and propanol) have a specific alcoholic smell, butanol and pentanol have a sweet suffocating smell. Alcohols containing more than 6 carbon atoms are odorless.

Methyl, ethyl and propyl alcohols dissolve well in water. As the molecular weight increases, the solubility of alcohols in water decreases.

A significantly higher boiling point of alcohols compared to hydrocarbons containing the same number of carbon atoms (for example, t bale (CH 4) \u003d - 161 0 С, and t bale (CH 3 OH) \u003d 64.7 0 С) is associated with the ability alcohols form hydrogen bonds, and hence the ability of molecules to associate.

××× Н – О ×××Н – О ×××Н – О ×××R – alcohol radical

When alcohol is dissolved in water, hydrogen bonds also occur between the molecules of alcohol and water. As a result of this process, energy is released and volume decreases. So, when mixing 52 ml of ethanol and 48 ml of water, the total volume of the resulting solution will not be 100 ml, but only 96.3 ml.

fire hazard represent both pure alcohols (especially lower ones), the vapors of which can form explosive mixtures, and aqueous solutions of alcohols. Aqueous solutions of ethanol in water with an alcohol concentration of more than 25% or more are flammable liquids.

Chemical properties alcohols

The chemical properties of alcohols are determined by the reactivity of the hydroxyl group and the structure of the radical associated with the hydroxyl group.

1. Reactions of hydroxyl hydrogen R - O - H

Due to the electronegativity of the oxygen atom in alcohol molecules, there is a partial distribution of charges:

Hydrogen has a certain mobility and is able to enter into substitution reactions.

1.1. Interaction with alkali metals - the formation of alcoholates:

2CH 3 - CH - CH 3 + 2Na ® 2CH 3 - CH - CH 3 + H 2

propanol-2 sodium isopropoxide

(sodium salt of propanol-2)

Salts of alcohols (alcoholates) are solids. When they are formed, alcohols act as very weak acids.

Alcoholates are easily hydrolyzed:

C 2 H 5 ONa + HOH ® C 2 H 5 OH + NaOH

sodium ethoxide

1.2. Interaction with carboxylic acids (esterification reaction) - formation of esters:

H 2 SO 4 conc.

CH 3 - CH - OH + HO - C - CH 3 ¾¾® CH 3 - CH - O - C - CH 3 + H 2 O

CH 3 O CH 3 O

acetic acid isopropyl acetate

(isopropyl ether

acetic acid)

1.3. Interaction with inorganic acids:

CH 3 - CH - OH + HO -SO 2 OH ® CH 3 - CH - O - SO 2 OH + H 2 O

sulfuric acid isopropylsulfuric acid

(isopropyl ether

sulfuric acid)

1.4. Intermolecular dehydration - the formation of ethers:

H 2 SO 4 conc., t<140 0 C

CH 3 - CH - OH + BUT - CH - CH 3 ¾¾¾® CH 3 - CH - O - CH - CH 3 + H 2 O

CH 3 CH 3 CH 3 CH 3

diisopropyl ether

2. Reactions of the hydroxyl group R - OH

2.1. Interaction with hydrogen halides:

H 2 SO 4 conc.

CH 3 - CH - CH 3 + HCl ¾¾® CH 3 - CH - CH 3 + H 2 O

2-chloropropane

2.2. Interaction with halogen derivatives of phosphorus:

CH 3 - CH - CH 3 + PCl 5 ¾® CH 3 - CH - CH 3 + POCl 3 + HCl

2-chloropropane

2.3. Intramolecular dehydration - obtaining alkenes:

H 2 SO 4 conc., t> 140 0 C

CH 3 - CH - CH 2 ¾¾¾® CH 3 - CH \u003d CH 2 + H 2 O

½ ½ propene

During the dehydration of an asymmetric molecule, the elimination of hydrogen proceeds predominantly from least hydrogenated carbon atom ( rule A.M. Zaitsev).

3. Oxidation reactions.

3.1. Complete oxidation - combustion:

C 3 H 7 OH + 4.5O 2 ® 3CO 2 + 4H 2 O

Partial (incomplete) oxidation.

Oxidizers can be potassium permanganate KMnO 4 , a mixture of potassium bichromate with sulfuric acid K 2 Cr 2 O 7 + H 2 SO 4 , copper or platinum catalysts.

When primary alcohols are oxidized, aldehydes are formed:

CH 3 - CH 2 - CH 2 - OH + [O] ® [CH 3 - C - OH] ® CH 3 - CH 2 - C \u003d O + H 2 O

propanol-1 propanal

The oxidation reaction of methanol when this alcohol enters the body is an example of the so-called “lethal synthesis”. Methyl alcohol itself is a relatively harmless substance, but in the body, as a result of oxidation, it turns into extremely toxic substances: methanal (formaldehyde) and formic acid. As a result, ingestion of 10 g of methanol leads to loss of vision, and 30 g leads to death.

The reaction of alcohol with copper (II) oxide can be used as a qualitative reaction for alcohols, because As a result of the reaction, the color of the solution changes.

CH 3 - CH 2 - CH 2 - OH + CuO ® CH 3 - CH 2 - C \u003d O + Cu¯ + H 2 O

propanol-1 propanal

As a result of partial oxidation of secondary alcohols, ketones are formed:

CH 3 - CH - CH 3 + [O] ® CH 3 - C - CH 3 + H 2 O

propanol-2 propanone

Tertiary alcohols do not oxidize under such conditions, and when oxidized under more severe conditions, the molecule is split, and a mixture of carboxylic acids is formed.

The use of alcohols

Alcohols are used as excellent organic solvents.

Methanol is obtained from large volume and used for the preparation of dyes, non-freezing mixtures, as a source for the production of various polymer materials(obtaining formaldehyde). It should be remembered that methanol is highly toxic.

Ethyl alcohol is the first organic substance that was isolated in its pure form in 900 in Egypt.

Currently, ethanol is a large-tonnage product of the chemical industry. It is used to produce synthetic rubber, organic dyes, and the manufacture of pharmaceuticals. In addition, ethyl alcohol is used as an environmentally friendly fuel. Ethanol is used in the manufacture of alcoholic beverages.

Ethanol is a drug that stimulates the body; its prolonged and excessive use leads to alcoholism.

Butyl and amyl alcohols (pentanols) are used in industry as solvents, as well as for the synthesis of esters. All of them are highly toxic.

Polyhydric alcohols

Polyhydric alcohols contain two or more hydroxyl groups at different carbon atoms.

CH 2 - CH 2 CH 2 - CH - CH 2 CH 2 - CH - CH - CH - CH 2

ç ç ç ç ç ç ç ç ç ç

OH OH OH OH OH OH OH OH

ethanediol-1,2 propanetriol-1,2,3 pentanpentol-1,2,3,4,5

(ethylene glycol) (glycerin) (xylitol)

Physical properties of polyhydric alcohols

Ethylene glycol (“glycols” is the common name for dihydric alcohols) is a colorless viscous liquid It is highly soluble in water and in many organic solvents.

Glycerin - the most important trihydric alcohol - is a colorless, thick liquid that is highly soluble in water. Glycerin has been known since 1779 after its discovery by the Swedish chemist K Scheele.

Polyhydric alcohols containing 4 or more carbon atoms are solids.

The more hydroxyl groups in a molecule, the better it dissolves in water and the higher its boiling point. In addition, a sweet taste appears, and the more hydroxyl groups in a substance, the sweeter it is.

Substances such as xylitol and sorbitol are used as sugar substitutes:

CH 2 - CH - CH - CH - CH 2 CH 2 - CH - CH - CH - CH - CH 2

ç ç ç ç ç ç ç ç ç ç ç

OH OH OH OH OH OH OH OH OH

xylitol sorbitol

The six-hydric alcohol “inositol” also tastes sweet. Inositol is found in legumes, kidneys, liver, muscles. Inositol has a common formula with glucose:

NO -HC CH - OH

NO -NS CH - OH C 6 H 12 O 6.

cyclohexanehexol

Methods for obtaining polyhydric alcohols

1. Incomplete oxidation of alkenes

Partial oxidation with KMnO 4 potassium permanganate solution.

1.1. Ethylene oxidation

CH 2 \u003d CH 2 + [O] + HOH ® CH 2 - CH 2

ethylene ½ ½

ethanediol-1,2

(ethylene glycol)

1.2. propene oxidation

CH 2 \u003d CH - CH 3 + [O] + HOH ® CH 2 - CH - CH 2

propene ½ ½ ½

propanetriol-1,2,3,

(glycerol)

2. Saponification of vegetable and animal fats

Glycerin is obtained as a by-product in the soap industry during the processing of fats.

CH - O - OS - C 17 H 35 + 3NaOH® CH - OH + 3 C 17 H 35 COOHa

CH 2 - O - OS - C 17 H 35 CH 2 - OH

triglyceride glycerin sodium stearate

stearic acid (soap)

Chemical properties of polyhydric alcohols

The chemical properties of polyhydric alcohols are in many ways similar to those of monohydric alcohols.

1. Interaction with active metals

CH 2 - OH CH 2 - ONa

ç + 2Na®ç + H 2

CH 2 - OH CH 2 - ONa

ethylene glycol sodium salt of ethylene glycol

2. Formation of esters with mineral acids

CH 2 - OH + HO - NO 2 CH 2 - O - NO 2

CH - OH + HO - NO 2 ® CH - O - NO 2 + 3H 2 O

CH 2 - OH + HO - NO 2 CH 2 - O - NO 2

glycerin nitric trinitroglycerin

Trinitroglycerin is one of the strongest explosives; it explodes from impact, concussion, fuse, as a result of self-decomposition. For practical use, in order to increase safety when working with trinitroglycerin, it is transferred to dynamite(porous materials impregnated with trinitroglycerin - diatomaceous earth, wood flour, etc.).

3. Interaction with copper (II) hydroxide - a qualitative reaction to glycerol

CH 2 - OH CH 2 - O m H / O - CH 2

2 CH - OH + Cu (OH) 2 ® CH - O / HO - C H

CH 2 - OH CH 2 - OH HO - CH 2

copper diglycerate

(bright blue coloration)

4. Dehydration of glycerol with the formation of acrolein

C 3 H 8 O 3 ® CH 2 \u003d CH - C \u003d O + 2H 2 O

glycerin ç

acrolein (suffocating odor when calcined fats)

5. Oxidation reactions

Ethylene glycol and glycerin, when interacting with strong oxidizing agents (potassium permanganate KMnO 4, chromium oxide (VI) CrO 3), are prone to spontaneous combustion.

5C 3 H 8 O 3 + 14KMnO 4 + 21H 2 SO 4 ® 15CO 2 + 14MnSO 4 + 7K 2 SO 4 + 41H 2 O

The use of polyhydric alcohols

Ethylene glycol and glycerin are used to make antifreeze liquids - antifreeze. So, an aqueous 50% solution of glycerin freezes only at -34 0 C, and a solution composed of 6 parts of ethylene glycol and 1 part of water freezes at a temperature of -49 0 C.

Propylene glycol CH 3 - CH (OH) - CH 2 - CH 2 OH is used to obtain water-free foams (such foams are more stable), and is also integral part sun creams.

Ethylene glycol is used to produce lavsan fiber, and glycerin is used to produce glyptal resins.

In large quantities, glycerin is used in the perfumery, medical and food industries.

Phenols

Phenols- derivatives of aromatic hydrocarbons, in which the hydroxyl group OH- is attached directly to the carbon atom of the benzene ring.

The hydroxyl group is linked to an aromatic radical (phenyl). The p-electrons of the benzene ring involve the unshared electrons of the oxygen atom of the OH group into their system, as a result of which the hydrogen of the hydroxyl group becomes more mobile than in aliphatic alcohols.

Physical properties

The simplest representative - phenol - is a colorless crystalline substance (melting point 42 0 C) with a characteristic odor. The trivial name of phenol is carbolic acid.

Monatomic phenols are sparingly soluble in water; with an increase in the number of hydroxyl groups, the solubility in water increases. Phenol at a temperature of 60 0 C dissolves in water without limit.

All phenols are highly toxic. Phenol causes burns on contact with skin.

Methods for obtaining phenol

1. Obtaining from coal tar

This is the most important technical way obtaining phenol. It consists in the fact that the fractions of coal tar obtained during the coking of coal are treated with alkalis, and then for neutralization with acids.

2. Obtaining from halogen derivatives of benzene

C 6 H 5 Cl + NaOH conc. aq. solution ® C 6 H 5 OH + NaCl

chlorobenzenephenol

Chemical properties of phenols

1. Reactions involving hydroxyl hydrogen C 6 H 5 - O - H

1.1. Interaction with active metals

2C 6 H 5 OH + 2Na® 2C 6 H 5 ONa + H 2

phenol phenolate

sodium (salt)

1.2. Interaction with alkalis

Phenol is a stronger acid than monohydric alcohols and therefore, unlike the latter, phenol reacts with alkali solutions:

C 6 H 5 OH + NaOH ® C 6 H 5 ONa + H 2 O

phenol phenolate

Phenol is a weaker acid than carbonic acid H 2 CO 3 (about 300 times) or hydrosulfide acid H 2 S, so phenolates are decomposed by weak acids:

C 6 H 5 ONa + H 2 O + CO 2 ® C 6 H 5 OH + NaHCO 3

1.3. Formation of ethers and esters

H 2 SO 4 conc.

C 6 H 5 OH + HO - C 2 H 5 ¾¾¾®C 6 H 5 O - C 2 H 5 + H 2 O

2. Reactions involving the benzene ring

Phenol without heating and without catalysts vigorously enters into reactions of substitution of hydrogen atoms, while trisubstituted derivatives are almost always formed

2.1. Interaction with bromine water - a qualitative reaction to phenol

2.2. Interaction with nitric acid

Picric acid is a yellow crystalline substance. When heated carefully, it melts at a temperature of 122 0 C, and when heated rapidly, it explodes. Salts of picric acid (picrates) explode on impact and friction.

3. Polycondensation reaction with formaldehyde

The interaction of phenol with formaldehyde with the formation of resinous products was studied as early as 1872 by Bayer. wide practical use this reaction took place much later - in the 20-30s of the 20th century, when in many countries so-called bakelites began to be prepared from phenol and formaldehyde.

4. Staining reaction with ferric chloride

All phenols, when interacting with ferric chloride FeCl 3, form colored compounds; monatomic phenols give violet or of blue color. This reaction can serve as a qualitative reaction for phenol.

The use of phenols

Phenols kill many microorganisms, which is used in medicine, using phenols and their derivatives as disinfectants and antiseptics. Phenol (carbolic acid) was the first antiseptic introduced into surgery by Lister in 1867. The antiseptic properties of phenols are based on their ability to fold proteins.

"Phenolic coefficient" - a number showing how many times the antiseptic effect of a given substance is greater (or less) than the action of phenol, taken as a unit. Benzene homologues - cresols - have a stronger bactericidal effect than phenol itself.

Phenol is used to produce phenol-formaldehyde resins, dyes, picric acid, and is also used to produce medications such as salicylates, aspirin and others.

One of the most well-known derivatives of dihydric phenols is adrenaline. Adrenaline is a hormone produced by the adrenal glands and has the ability to constrict blood vessels. It is often used as a hemostatic agent.

Question #3

Ethers called organic compounds in which two hydrocarbon radicals are linked by an oxygen atom. Ethers can be considered as products of substitution of a hydrogen atom in the hydroxyl of an alcohol by a radical:

R – O – H ® R – O – R /

General formula of ethers C n H 2 n +2 O.

The radicals in an ether molecule can be the same, for example, in CH 3 - O - CH 3 ether, or different, for example, in CH 3 - O - C 3 H 7 ether. Ether having different radicals is called mixed.

Ether nomenclature

Esters are usually named according to the radicals that are part of their composition (rational nomenclature).

According to the international nomenclature, ethers are designated as derivatives of hydrocarbons in which the hydrogen atom is substituted alkoxy group(RO -), for example, a methoxy group CH 3 O -, an ethoxy group C 2 H 5 O -, etc.

Ether isomerism

1. The isomerism of ethers is determined by the isomerism of the radicals associated with oxygen.

CH 3 - O - CH 2 - CH 2 - CH 3 methyl propyl ether

C 2 H 5 - O - C 2 H 5 diethyl ether

CH 3 - O - CH - CH 3 methyl isopropyl ether

2. Interclass isomers of ethers are monohydric alcohols.

CH 3 - CH 2 - CH 2 - CH 2 - OH

butanol-1

Physical properties of ethers

Dimethyl and methyl ethyl ethers are gaseous substances under normal conditions.

Starting with diethyl ether, substances of this class are colorless, easily mobile liquids with a characteristic odor.

Ethers are lighter than water and almost insoluble in it. Due to the absence of hydrogen bonds between molecules, ethers boil at a lower temperature than the corresponding alcohols.

In organic solvents, ethers dissolve easily and dissolve many substances themselves.

The most common compound of this class is diethyl ether C 2 H 5 - O - C 2 H 5, first obtained in the 16th century by Kordus. Very often it is called "sulfuric ether". This name, obtained in the 18th century, is associated with a method for obtaining ether: the interaction of ethyl alcohol with sulfuric acid.

Diethyl ether is a colorless, very mobile liquid with a strong characteristic odor. This substance is extremely explosive and flammable. The boiling point of diethyl ether is 34.6 0 C, the freezing point is 117 0 C. The ether is poorly soluble in water (1 volume of ether dissolves in 10 volumes of water). Ether is lighter than water (density 714 g/l). Diethyl ether is prone to electrification: discharges of static electricity can occur at the time of transfusion of ether and cause it to ignite. Vapors of diethyl ether are 2.5 times heavier than air and form explosive mixtures with it. Concentration limits of flame propagation (CPR) 1.7 - 49%.

Ether vapor can spread over considerable distances, while maintaining the ability to burn. Basic precautions when working with ether - this is the distance from open flames and very hot appliances and surfaces, including electric stoves.

The flash point of the ether is 45 0 С, the self-ignition temperature is 164 0 С. When burning, the ether burns with a bluish flame with the release a large number heat. The flame of the ether is growing rapidly, because. upper layer it quickly heats up to boiling point. When burning, the ether heats up in depth. The growth rate of the heated layer is 45 cm/hour, and the rate of its burnout from the free surface is 30 cm/hour.

Upon contact with strong oxidizing agents (KMnO 4 , CrO 3 , halogens), diethyl ether ignites spontaneously. In addition, upon contact with atmospheric oxygen, diethyl ether can form peroxide compounds, which are extremely explosive substances.

Methods for obtaining ethers

1. Intermolecular dehydration of alcohols

H 2 SO 4 conc.

C 2 H 5 - OH + BUT - C 2 H 5 ¾¾¾® C 2 H 5 - O - C 2 H 5 + H 2 O

ethanol diethyl ether

Chemical properties of ethers

1. Ethers are rather inert substances, not prone to chemical reactions. However, under the action of concentrated acids, they decompose

C 2 H 5 - O - C 2 H 5 + HI conc. ® C 2 H 5 OH + C 2 H 5 I

diethyl ethanol iodoethane

2. Oxidation reactions

2.1. Complete oxidation - combustion:

C 4 H 10 O + 6 (O 2 + 3.76N 2) ® 4CO 2 + 5H 2 O + 6 × 3.76N 2

2.2. incomplete oxidation

When standing, especially in the light, the ether oxidizes and decomposes under the influence of oxygen with the formation of toxic and explosive products - peroxide compounds and products of their further decomposition.

O - C - CH 3

C 2 H 5 - O - C 2 H 5 + 3 [O] ® ½

O - C - CH 3

hydroxyethyl hydroperoxide

The use of ethers

Diethyl ether is good organic solvent. It is used to extract various useful substances from plants, for cleaning fabrics, in the manufacture of gunpowder and artificial fibers.

In medicine, ether is used for general anesthesia. For the first time for this purpose, during a surgical operation, ether was used by the American physician Jackson in 1842. The Russian surgeon N.I. ardently fought for the introduction of this method. Pirogov.

Question number 4. Carbonyl compounds (30 min)

Aldehydes and ketones- derivatives of hydrocarbons, the molecules of which contain one or more carbonyl groups С = O.

Aldehydes	Ketones
Aldehydes contain a carbonyl group associated with one radical and one hydrogen atom - C \u003d O ½ H	Ketones contain a carbonyl group linked to two radicals - C - ll O
The general formula of carbonyl compounds C n H 2 n O
Nomenclature of carbonyl compounds
The name aldehydes comes from general way obtaining these compounds: alcohol dehydrogenation, i.e. removal of hydrogen. According to the IUPAC nomenclature, the name of aldehydes is derived from the names of the corresponding hydrocarbons, adding the suffix “al” to them. The chain numbering starts from the aldehyde group.	According to the IUPAC nomenclature, the name of ketones is derived from the names of the corresponding hydrocarbons, adding the suffix “he” to them. The numbering is carried out from the end of the chain closest to the carbonyl. The first representative of the ketone series contains 3 carbon atoms.
H - C \u003d O methanal ½ (formaldehyde, H formaldehyde) CH 3 - C \u003d O ethanal ½ (acetic aldehyde, H acetaldehyde) 5 4 3 2 1 CH 3 - CH - CH 2 - CH 2 - C \u003d O ½ ½ CH 3 H 4-methylpentanal	CH 3 - C - CH 3 propanone ll (acetone) O 6 5 4 3 2 1 CH 3 - CH 2 - CH - CH 2 - C - CH 3 ½ ll CH 3 O 4-methylhexanone-2
Isomerism of unsaturated compounds
1. Isomerism of the carbon chain
CH 3 - CH 2 - CH 2 - CH 2 - CH 2 - C \u003d O ½ hexanal H CH 3 - CH - CH - C \u003d O ½ ½ ½ CH 3 CH 3 H 2,3-dimethylbutanal	CH 3 - CH 2 - CH 2 - CH 2 - CH 2 - C - CH 3 ll heptanone-2 O CH 3 - CH 2 - CH - C - CH 3 ½ ll C 2 H 5 O 3-ethylpentanone-2
	2. Isomerism of the position of the carbonyl group
	CH 3 - CH 2 - CH 2 - CH 2 - CH 2 - C - CH 3 ll heptanone-2 O CH 3 - CH 2 - CH 2 - C - CH 2 - CH 2 - CH 3 ll heptanone-4 O
3. Aldehydes and ketones are interclass isomers
Physical properties of carbonyl compounds
Formaldehyde (methanal) under normal conditions is a gas with a sharp unpleasant “pungent” odor, highly soluble in water. A 40% solution of formaldehyde in water is called formalin. Acetic aldehyde (ethanal) is a volatile, flammable liquid. Its boiling point is 20.2 0 C, the flash point is -33 0 C. In high concentrations, it has an unpleasant suffocating odor; in small concentrations, it has a pleasant smell of apples (in which it is contained in a small amount). Acetic aldehyde is highly soluble in water, alcohol, and many other organic solvents.	The simplest ketone, propanone (acetone), is a flammable liquid. Subsequent representatives are also liquids. Higher aliphatic (> 10 C atoms) as well as aromatic ketones are solids. Acetone has low temperature boiling point 56.1 0 C and flash point -20 0 C. The simplest ketones are mixed with water. Aqueous solutions of acetone are also dangerous. So, a 10% solution of it in water has a flash point of 11 0 C. All ketones are readily soluble in alcohol and ether. The simplest ketones have a characteristic odor; average homologues have a rather pleasant smell, reminiscent of the smell of mint.
Methods for the preparation of carbonyl compounds
1. Reactions of partial (incomplete) oxidation of alcohols
Primary alcohols, when oxidized, give aldehydes: CH 3 - CH 2 - CH 2 - OH + [O]® H 2 O + propanol-1 + CH 3 - CH 2 - C \u003d O propanal ½ H	Secondary alcohols form ketones during oxidation: CH 3 - CH - CH 2 -CH 3 + [O] ® H 2 O + ½ OH + CH 3 - C - CH 2 - CH 3 butanol-2 ll O butanone-2
2. Hydration of alkynes (Kucherov reaction)
Aldehyde is obtained only when acetylene is hydrated; in all other cases, ketones are formed. Hg 2+ CH º CH + HOH ® CH 3 - C \u003d O + H 2 O acetylene ½ H ethanal	Hg 2+ CH º C - CH 2 - CH 3 + HOH ® H 2 O + butin-1 + CH 3 - C - CH 2 - CH 3 ll O butanone-2
3. Hydrolysis of dihalogen derivatives. (Halogen atoms are located on the same carbon atom). The reaction proceeds in an aqueous solution of alkali.
Cl ½ CH 3 - CH 2 - CH + 2KOH water ® Cl 1,1-dichloropropane ® 2KCl + CH 3 - CH 2 - C \u003d O + H 2 O ½ H propanal	Cl ½ CH 3 - CH 2 - C - CH 3 + 2KOH water ® ½ Cl 2,2-dichlorobutane ® 2KCl + CH 3 - CH 2 - C - CH 3 + H 2 O ll O butanone-2
4. Recovery of carboxylic acids
CH 3 - CH 2 - C \u003d O + H 2 ® ½ OH propanoic acid ® H 2 O + CH 3 - CH 2 - C \u003d O ½ H propanal
Chemical properties of carbonyl compounds
In terms of chemical activity, aldehydes are superior to ketones and are more reactive. The radicals associated with the carbonyl group have the so-called positive inductive effect: they increase the electron density of the bond of the radical with other groups, i.e. as if quenching the positive charge of the carbon atom of carbonyl. As a result, carbonyl compounds, according to the decrease in their chemical activity, can be arranged in the following row: H - C d + - H> H 3 C ® C d + - H> H 3 C ® C d + CH 3 II II II O d - O d - About d - (straight arrows in the formulas show the shift of electrons, the quenching of a positively charged carbon atom of the carbonyl group).
1. Addition reactions at the double bond break >C = O. Recovery reactions.
CH 3 - CH 2 - C \u003d O + H 2 ® ½ H propanal ® CH 3 - CH 2 - CH 2 - OH (propanol-1)	CH 3 - CH 2 - C - CH 3 + H 2 ® II O butanone-2 ® CH 3 - CH 2 - CH - CH 3 ½ OH butanol-2
2. Oxidation reactions
2.1. Complete oxidation - combustion
C 3 H 6 O + 4O 2 ® 3CO 2 + 3H 2 O	C 4 H 8 O + 5.5 O 2 ® 4CO 2 + 4H 2 O
2.2. Partial (incomplete) oxidation
Oxidation reactions with silver oxide ("silver mirror reaction"), copper (II) hydroxide - qualitative reactions for aldehydes. NH 3, t CH 3 - CH 2 - C \u003d O + Ag 2 O ¾¾® ½ H propanal ¾¾® 2Ag¯ + CH 3 - CH 2 - C \u003d O ½ OH propanoic acid In this case, silver precipitates. CH 3 - CH 2 - C \u003d O + 2Cu (OH) 2 ® ½ H propanal ® Cu 2 O + CH 3 - CH 2 - C \u003d O + H 2 O ½ OH propanoic acid The blue precipitate of copper hydroxide turns into a red precipitate of nitrous oxide copper.	The oxidation of ketones is very difficult only with strong oxidizing agents (chromium mixture, KMnO 4), as a result, a mixture of acids is formed: t CH 3 - CH 2 - C - CH 3 + [O] ® II O butanone-2 ® 2CH 3 - C \u003d O ½ OH acetic (ethanoic) acid or ® CH 3 - CH 2 - C \u003d O + H - C \u003d O ½ ½ OH OH propanoic formic acid (methanoic) acid
Upon contact with strong oxidizing agents (KMnO 4 , CrO 3 , HNO 3 conc., H 2 SO 4 conc.), aldehydes and ketones ignite spontaneously.
3. Reactions due to transformations in radicals. Replacement of hydrogen in radicals by halogens
CH 3 - C \u003d O + Cl 2 ® HCl + CH 2 Cl - C \u003d O ½ ½ H H ethanal chloroacetic aldehyde When methanal is chlorinated, poisonous phosgene gas is formed: H - C \u003d O + 2Cl 2 ®Cl - C \u003d O + 2HCl ½½ HCl phosgene	CH 3 - C - CH 3 + Br 2 ® HBr + CH 3 - C - CH 2 Br II II O O acetone bromoacetone Bromoacetone and chloroacetone are tear chemical warfare agents ( lachrymators).
Application of carbonyl compounds
Formaldehyde is used in industry for the production of phenol-formaldehyde and urea polymers, organic dyes, adhesives, varnishes, and in the leather industry. Formaldehyde in the form of an aqueous solution (formalin) is used in medical practice. Acetaldehyde is the starting material for the production of acetic acid, polymeric materials, medicines, ethers.	Acetone very well dissolves a number of organic substances (for example, varnishes, nitrocellulose, etc.) and therefore in large quantities used as a solvent (production of smokeless powder, rayon, paints, film). Acetone is used as a raw material for the production of synthetic rubber. Pure acetone is used for extraction food products, vitamins and drugs, as well as a solvent for the storage and transportation of acetylene.

Question #5. Carboxylic acids (30 min)

carboxylic acids called derivatives of hydrocarbons that contain one or more carboxyl groups - C \u003d O.

The carboxyl group is a combination of carbonyl and hydroxyl groups: - C \u003d O + - C - ® - C \u003d O.

carbo nile + hydro xyl® carboxyl.

Carboxylic acids are oxidation products of aldehydes, which, in turn, are oxidation products of alcohols. On acids, the oxidation process is completed (with the preservation of the carbon skeleton) in the following series:

hydrocarbon ® alcohol ® aldehyde ® carboxylic acid.

Similar information.

Hydration of alkenes

In the presence of strong mineral acids, alkenes undergo a hydration reaction to form alcohols:

In the case of unsymmetrical alkenes, the addition occurs in accordance with Markovnikov's rule - the hydrogen atom of the water molecule is attached to the more hydrogenated carbon atom, and the hydroxy group to the less hydrogenated carbon atom at the double bond:

Hydrogenation (reduction) of aldehydes and ketones

Hydrogenation of aldehydes on metal catalysts (Pt, Pd or Ni) when heated leads to the formation of primary alcohols:

Under similar conditions, secondary alcohols are obtained from ketones:

Hydrolysis of esters

When strong mineral acids act on esters, they undergo hydrolysis with the formation of alcohol and carboxylic acid:

The hydrolysis of esters in the presence of alkalis is called saponification. This process is irreversible and leads to the formation of an alcohol and a carboxylic acid salt:

This process proceeds by the action of an aqueous solution of alkali on monohalogen derivatives of hydrocarbons:

Other methods for obtaining individual representatives of monohydric alcohols

Alcoholic fermentation of glucose

In the presence of some yeasts, more precisely under the action of the enzymes produced by them, the formation of ethyl alcohol from glucose is possible. At the same time, carbon dioxide is also formed as a by-product:

Production of methanol from synthesis gas

Synthesis gas is a mixture of carbon monoxide and hydrogen. The effect on this mixture of catalysts, heating and elevated pressures methanol is produced in industry:

Obtaining polyhydric alcohols

Wagner reaction (mild oxidation of alkenes)

Under the action of a neutral solution of potassium permanganate on alkenes in the cold (0 o C), vicinal dihydric alcohols (diols) are formed:

The scheme presented above is not a complete reaction equation. In this form, it is easier to remember it in order to be able to answer individual test questions. USE questions. However, if this reaction comes across in tasks of high complexity, then its equation must be written in full:

Chlorination of alkenes followed by hydrolysis

This method is two-stage and lies in the fact that at the first stage, the alkene enters into an addition reaction with a halogen (chlorine or bromine). For example:

And on the second, the resulting dihaloalkane is treated with an aqueous solution of alkali:

Getting glycerin

Main industrial way obtaining glycerol is alkaline hydrolysis of fats (saponification of fats):

Getting phenol

Three step method via chlorobenzene

This method is three-stage. At the first stage, bromination or chlorination of benzene is carried out in the presence of catalysts. Depending on the halogen used (Br 2 or Cl 2), the corresponding aluminum or iron (III) halide is used as a catalyst

At the second stage, the halogen derivative obtained above is treated with an aqueous solution of alkali:

In the third step, sodium phenolate is treated with a strong mineral acid. Phenol is displaced because it is a weak acid, i.e. low dissociating substance

Cumene oxidation

Obtaining aldehydes and ketones

Dehydrogenation of alcohols

During the dehydrogenation of primary and secondary alcohols on a copper catalyst, when heated, aldehydes and ketones are obtained, respectively.

Alcohol oxidation

With incomplete oxidation of primary alcohols, aldehydes are obtained, and secondary ones, ketones. In general, the scheme of such oxidation can be written as:

As you can see, the incomplete oxidation of primary and secondary alcohols leads to the same products as the dehydrogenation of these same alcohols.

Copper oxide can be used as oxidizing agents when heated:

Or other stronger oxidizing agents, such as a solution of potassium permanganate in an acidic, neutral, or alkaline environment.

Alkyne hydration

In the presence of mercury salts (often together with strong acids), alkynes undergo a hydration reaction. In the case of ethyne (acetylene), an aldehyde is formed, in the case of any other alkyne, a ketone:

Pyrolysis of salts of carboxylic acids of divalent metals

When salts of carboxylic acids of divalent metals, for example, alkaline earth, are heated, a ketone and a carbonate of the corresponding metal are formed:

Hydrolysis of geminal dihalogen derivatives

Alkaline hydrolysis of geminal dihalogen derivatives of various hydrocarbons leads to aldehydes if the chlorine atoms were attached to the extreme carbon atom and to ketones if not to the extreme:

Catalytic oxidation of alkenes

Acetaldehyde is obtained by catalytic oxidation of ethylene:

Obtaining carboxylic acids

Catalytic oxidation of alkanes

Oxidation of alkenes and alkynes

For this, an acidified solution of permanganate or potassium dichromate is most often used. In this case, a multiple carbon-carbon bond is broken:

Oxidation of aldehydes and primary alcohols

In this method of obtaining carboxylic acids, the most common oxidizing agents used are an acidified solution of potassium permanganate or dichromate:

By hydrolysis of trihalogenated hydrocarbons

At the first stage, the trihaloalkane is treated with an aqueous solution of alkali. In this case, a salt of a carboxylic acid is formed:

The second step is the treatment of the carboxylic acid salt with a strong mineral acid. Because carboxylic acids are weak, they are easily displaced by strong acids:

Hydrolysis of esters

From salts of carboxylic acids

This reaction has already been considered in the preparation of carboxylic acids by hydrolysis of trihalogen derivatives (see above). It lies in the fact that carboxylic acids, being weak, are easily displaced by strong inorganic acids:

Specific methods for obtaining acids

Obtaining formic acid from carbon monoxide

This method is industrial and lies in the fact that at the first stage carbon monoxide under pressure at high temperatures reacts with anhydrous alkali:

and on the second, the obtained formate is treated with a strong inorganic acid:

2HCOONa + H 2 SO 4 > 2HCOOH + Na 2 SO 4

The material considers the classification of oxygen-containing organic substances. Questions of homology, isomerism and nomenclature of substances are analyzed. The presentation is full of tasks on these issues. Consolidation of the material is offered in a test exercise for compliance.

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Lesson objectives: to get acquainted with the classification of oxygen-containing organic compounds; construction of homologous series of substances; detection possible types isomerism; construction of structural formulas of isomers of substances, nomenclature of substances.

Classification of substances C x H y O z carboxylic acids aldehydes ketones esters alcohols phenols monoatomic - many R - OH R - (OH) n simple complex OH \u003d R - C - O OH \u003d R - C - O H - oic acid -al R-C-R || O-one R - O - R \u003d R - C - O O - R - ol - n ol

Homologous series CH 3 - OH C 2 H 5 - OH C 3 H 7 - OH C 4 H 9 - OH C 5 H 11 - OH methanol ethanol propanol-1 butanol-1 pentanol-1 Alcohols C n H 2n+2O

Carboxylic acids \u003d H - C - O OH \u003d CH 3 - C - O OH \u003d CH 3 - CH 2 - C - O OH methane acid (formic) ethanoic acid (acetic) propanoic acid (propionic) C n H 2n O2

Aldehydes = H - C - O H \u003d CH 3 - C - O H \u003d CH 3 - CH 2 - C - O H

Ketones CH 3 - C - CH 3 || O CH 3 - CH 2 - C - CH 3 || O CH 3 - CH 2 - CH 2 - C - CH 3 || O propane he (acetone) butane he pentane he-2 C n H 2n O

Ethers CH 3 - O -CH 3 C 2 H 5 - O -CH 3 C 2 H 5 - O -C 2 H 5 C 3 H 7 - O -C 2 H 5 C 3 H 7 - O -C 3 H 7 dimethyl ether methethyl ether diethyl ether ethyl propyl ether dipropyl ether C n H 2n + 2 O Conclusion: ethers are derivatives of saturated monohydric alcohols.

Esters \u003d H - C - O O - CH 3 \u003d CH 3 - C - O O - CH 3 \u003d CH 3 - CH 2 - C - O O - CH 3 formic acid methyl ester (methyl formate) acetic acid methyl ester (methyl acetate ) propionic acid methyl ester C n H 2n O 2 Conclusion: esters are derivatives of carboxylic acids and alcohols.

alcohols esters ketones aldehydes carboxylic acids isomerism and nomenclature of carbon skeleton isomerism interclass (esters) carbon skeleton interclass (ketones) carbon skeleton f-group position (-С=О) interclass (aldehydes) carbon skeleton f-group position (-OH) interclass (ethers) carbon skeleton interclass

Drawing up formulas of isomers. Nomenclature of substances. Task: compose structural formulas possible isomers for substances of composition C 4 H 10 O; C 4 H 8 O 2; C 4 H 8 O. What classes do they belong to? Name all substances according to the systematic nomenclature. C 4 H 10 O C 4 H 8 O 2 C 4 H 8 O C n H 2n + 2 O C n H 2n O 2 C n H 2n O alcohols and ethers carboxylic acids and esters aldehydes and ketones

CH 3 - CH 2 - CH - CH 3 | OH CH 3 | CH 3 - C - CH 3 | OH CH 3 - O - CH 2 - CH 2 - CH 3 CH 3 - CH 2 - O - CH 2 - CH 3 butanol-1 2-methylpropanol-1 butanol-2 2-methylpropanol-2 methyl propyl ether diethyl ether I alcohols II alcohol III alcohol

CH 3 - CH 2 - CH 2 - C - O OH \u003d CH 3 - CH - C - O OH | CH3 \u003d CH 3 - CH 2 - C - O O - CH 3 \u003d CH 3 - C - O O - CH 2 - CH 3 butanoic acid 2-methylpropanoic acid methyl propionic acid ethyl ester of acetic acid

CH 3 - CH 2 - CH 2 - C - O H \u003d CH 3 - CH - C - O H | CH3 CH 3 - CH 2 - C - CH 3 || O butanal 2-methylpropanal butanone-2

Check yourself! 1. Establish correspondence: general formula class substance R - COOH R - O - R R - COH R - OH R - COOR 1 R - C - R || O sl. esters alcohols carb. to-you ketones aldehydes etc. esters a) C 5 H 11 -OH b) C 6 H 13 -SON c) C 4 H 9 -O - CH 3 d) C 5 H 11 -COOH e) CH 3 -CO - CH 3 f) CH 3 -COOS 2 H 5 2. Name the substances according to the systematic nomenclature.

Check yourself! I II III IV V VI 3 6 5 2 1 4 D C B A E D

Homework Paragraph (17-21) - parts 1 and 2 of ex. 1,2,4,5 pp. 153-154 2 pp. 174 The lesson is over!

Target: to form the ability to make observations and draw conclusions, write down the equations of the corresponding reactions in molecular and ionic forms .

Security of the lesson

1. Collection guidelines for students to complete practical exercises and laboratory work on the discipline "Chemistry".

2. Sodium hydroxide solution, sodium carbonate, calcium carbonate, copper (II) oxide, acetic acid, litmus blue, zinc; stand with test tubes, water bath, heating device, matches, test tube holder.

Theoretical material

Carboxylic acids are organic compounds whose molecules contain one or more carboxyl groups connected to a hydrocarbon radical or a hydrogen atom.

Obtaining: In the laboratory, carboxylic acids can be obtained from their salts by treating them with sulfuric acid when heated, for example:

2CH 3 - COOHa + H 2 SO 4 ® 2CH 3 - COOH + Na 2 SO 4
In industry, it is obtained by oxidation of hydrocarbons, alcohols and aldehydes.

Chemical properties:
1. Due to the shift in electron density from the hydroxyl group O–H to strongly

polarized carbonyl group C=O, carboxylic acid molecules are capable of

electrolytic dissociation: R–COOH → R–COO - + H +

2.Carboxylic acids have properties characteristic of mineral acids. They react with active metals, basic oxides, bases, salts of weak acids. 2CH 3 COOH + Mg → (CH 3 COO) 2 Mg + H 2

2CH 3 COOH + CaO → (CH 3 COO) 2 Ca + H 2 O

H–COOH + NaOH → H–COONa + H2O

2CH 3 CH 2 COOH + Na 2 CO 3 → 2CH 3 CH 2 COONa + H 2 O + CO 2

CH 3 CH 2 COOH + NaHCO 3 → CH 3 CH 2 COONa + H 2 O + CO 2

Carboxylic acids are weaker than many strong mineral acids

CH 3 COONa + H 2 SO 4 (conc.) →CH 3 COOH + NaHSO 4

3. Formation of functional derivatives:

a) when interacting with alcohols (in the presence of concentrated H 2 SO 4), esters are formed.

The formation of esters by the interaction of an acid and an alcohol in the presence of mineral acids is called an esterification reaction. CH 3 - -OH + HO-CH 3 D CH 3 - -OCH 3 + H 2 O

acetic acid methyl methyl ester

acetic acid alcohol

The general formula of esters is R– –OR’ where R and R" are hydrocarbon radicals: in formic acid esters – formates –R=H.

The reverse reaction is the hydrolysis (saponification) of the ester:

CH 3 – –OCH 3 + HO–H DCH 3 – –OH + CH 3 OH.

Glycerin (1,2,3-trihydroxypropane; 1,2,3-propanetriol) (glycos - sweet) chemical compound with the formula HOCH2CH(OH)-CH2OH or C3H5(OH)3. The simplest representative of trihydric alcohols. It is a viscous transparent liquid.

Glycerin is a colorless, viscous, hygroscopic liquid, infinitely soluble in water. Sweet taste (glycos - sweet). It dissolves many substances well.

Glycerol is esterified with carboxylic and mineral acids.

Esters of glycerol and higher carboxylic acids are fats.

Fats - these are mixtures of esters formed by the trihydric alcohol glycerol and higher fatty acids. The general formula of fats, where R are the radicals of higher fatty acids:

Most often, fats include saturated acids: palmitic C15H31COOH and stearic C17H35COOH, and unsaturated acids: oleic C17H33COOH and linoleic C17H31COOH.

The common name for compounds of carboxylic acids with glycerol is triglycerides.

b) when exposed to water-removing reagents as a result of intermolecular

dehydration anhydrides are formed

CH 3 – –OH + HO– –CH 3 →CH 3 – –O– –CH 3 + H 2 O

Halogenation. Under the action of halogens (in the presence of red phosphorus), α-halo-substituted acids are formed:

Application: in the food and chemical industries (production of cellulose acetate, from which acetate fiber, organic glass, film are obtained; for the synthesis of dyes, medicines and esters).

Questions to consolidate the theoretical material

1 Which organic compounds are carboxylic acids?

2 Why are there no gaseous substances among carboxylic acids?

3 What causes the acidic properties of carboxylic acids?

4 Why does the color of indicators change in acetic acid solution?

5 What chemical properties do glucose and glycerol have in common, and how do these substances differ from each other? Write the equations for the corresponding reactions.

Exercise

1. Repeat theoretical material on the topic of the practice.

2. Answer questions to consolidate the theoretical material.

3. Investigate the properties of oxygen-containing organic compounds.

4. Prepare a report.

Execution instructions

1. Familiarize yourself with the safety rules when working in a chemical laboratory and sign in the safety journal.

2. Perform experiments.

3. Enter the results in the table.

Experience No. 1 Testing a solution of acetic acid with litmus

Dilute the resulting acetic acid with a little water and add a few drops of blue litmus or dip an indicator paper into the test tube.

Experience No. 2 Reaction of acetic acid with calcium carbonate

Pour a little chalk (calcium carbonate) into a test tube and add a solution of acetic acid.

Experience No. 3 Properties of glucose and sucrose

a) Add 5 drops of glucose solution, a drop of copper (II) salt solution and, while shaking, a few drops of sodium hydroxide solution into a test tube until a light blue solution is formed. This experiment was done with glycerin.

b) Heat the resulting solutions. What are you watching?

Experience No. 4 Qualitative reaction to starch

To 5-6 drops of starch paste in a test tube, add a drop of iodine alcohol solution.

Sample report

Laboratory work№ 9 Chemical properties of oxygen-containing organic compounds.

Purpose: to form the ability to make observations and draw conclusions, write down the equations of the corresponding reactions in molecular and ionic forms .

Make a conclusion in accordance with the purpose of the work

Literature 0-2 s 94-98

Lab #10

And their presence in nature

45. Name the substances, characterize each alcohol according to the classification of alcohols:

a) CH 3 ─CH 2 ─ CH─CH 2 ─CH 3 b) CH 3 ─ CH ─ CH─CH 3

c) CH 3 ─CH \u003d CH─CH 2 ─OH d) HO─CH 2 ─CH 2 ─CH 2 ─CH 2 ─OH

e) CH 3 ─ CH ─ C─CH 3 f) HO─CH 2 ─C≡C─CH 2 ─OH g) CH 3 ─ CH─CH 2 OH

Compose the structural formulas of the substances that form the winning path, if it is known that they all have a branched structure. Name the substances.

49. Which of the following substances can react with methyl alcohol: potassium, sodium oxide, water, copper (II) oxide, acetic acid, propanol-1, ethylene. Write the equations of possible reactions, indicate their type, flow conditions, name the products.

50. Solve chains of transformations:

CuO, t

KOH aq

HBr

CO → CH 3 OH → CH 3 Br → C 2 H 6 → C 2 H 5 Cl → C 2 H 5 OH

2) CH 2 \u003d CH─CH 3 X Y Z

51. When ethylene was oxidized with an aqueous solution of potassium permanganate, organic matter was obtained BUT. It dissolves copper (II) hydroxide to form a complex compound B bright blue. Substance processing BUT nitrating mixture leads to the product AT, which is a powerful explosive. Write the equations of all the mentioned reactions, name the substances BUT─AT.

52. Three numbered tubes contain colorless transparent liquids - water, ethanol, glycerin. How to recognize these substances? Write reaction equations, indicate their type, flow conditions, name the products.

53. Write the structural formulas of the following substances: a) 2,4-dichlorophenol, b) 4-ethylphenol, c) 3-nitrophenol, d) 1,2,3-trihydroxybenzene.

54. Arrange in a row by gain acid properties the following substances: P-nitrophenol, picric acid, about-cresol, phenol. Write the structural formulas of these substances in the required sequence and show the mutual influence of atoms in molecules.

55. Write the reaction equations by which phenol can be obtained from methane. Indicate the type of reactions, the conditions for their occurrence, name the products.

56. Determine the formula of limiting monohydric alcohol, if during the dehydration of a sample with a volume of 37 ml and a density of 1.4 g / ml, an alkene with a mass of 39.2 g was obtained.

57. Write and name all possible isomers of the composition C 5 H 10 O.

58. Formaldehyde, formed during the oxidation of 2 mol of methyl alcohol, was dissolved in 100 g of water. Calculate the mass fraction of formaldehyde in this solution.

59. Solve the chain of transformations:

1) CH 3 ─CHO → CH 3 ─CH 2 OH → CH 2 \u003d CH 2 → HC≡CH → CH 3 ─CHO

Acetylene → ethanal → ethanoic acid

ethylene → ethanol → dimethyl ether

60. Three test tubes contain colorless transparent liquids - acetaldehyde, glycerin, acetone. How to recognize these substances with the help of one reagent? Describe your actions and observations. Write the equations of possible reactions, indicate their type, flow conditions, name the products.

61. During the oxidation of some oxygen-containing organic matter weighing 1.8 g with an ammonia solution of silver oxide, silver was obtained weighing 5.4 g. What organic matter is oxidized?

62. Write the structural formulas of the following substances: a) 2-methylpropanoic acid, b) 3,4-dimethylheptanoic acid, c) butenoic acid, d) 2,3,4-trichlorobutanoic acid, e) 3-methyl- 2-ethylpetanoic acid, f) 2-methylbenzoic acid.

63. Arrange the following compounds in order of increasing acidic properties:

1) phenol, formic acid, hydrochloric acid, propanol-1, water

2) ethanol, P-cresol, hydrobromic acid, water, acetic acid, carbonic acid.

64. Which of the following substances will interact with a solution of acetic acid: Cu (OH) 2, Na 2 SiO 3, Hg, Mg, SO 3, K 2 CO 3, NaCl, C 2 H 5 OH, NaOH, Cu, CH 3 OH, CuO? Write the equations of possible reactions, indicate their type, conditions for the course and name the products.

65. In three numbered tubes are: ethyl alcohol, formic acid, acetic acid. How can these substances be recognized empirically? Write the reaction equations and describe the expected observations.

66. What volume of 80% vinegar essence with a density of 1.070 g / ml should be taken to prepare 6% table vinegar volume of 200 ml and a density of 1.007 g / ml?

67. Make formulas for esters and write the equations for the reactions of their preparation: a) propionic acid butyl ester, b) butyric acid ethyl ester, c) formic acid amyl ester, d) benzoic acid ethyl ester.

68. Methacrylic (2-methylpropenoic) acid methyl ester is used to produce a polymer known as plexiglass. Make up the reaction equations for obtaining this ether.

69. When methanol weighing 2.4 g and acetic acid weighing 3.6 g were heated, methyl acetate weighing 3.7 g was obtained. Determine the output of the ether.

70. Write the structural formulas of the following substances: a) tripalmitate, b) trioleate, c) dioleostearate, d) sodium palmitate, e) magnesium stearate.

71. Write the reaction equations, indicate their type, flow conditions, name the products:

1) fat synthesis based on stearic acid,

2) hydrolysis of fat based on linolenic acid in the presence of potassium hydroxide,

3) trioleate hydrogenation,

4) hydrolysis of dioleopalmitate in the presence of sodium hydroxide.

72. What mass of glycerin can be obtained from natural fat weighing 17.8 kg, containing 97% glycerol tristearate?

73. On average, sweet tooth put 2 teaspoons of sugar in a glass of tea. Knowing that 7 g of sugar is placed in such a spoon, and the volume of a glass is 200 ml, calculate the mass fraction of sucrose in the solution (take the density of tea equal to 1 g / ml).

74. Mixed 100 g of 10% and 200 g of 5% glucose solutions. What is the mass fraction of carbohydrate in the resulting solution?

75. Solve the chain of transformations: carbon dioxide → glucose → →ethanol → ethanal → ethanoic acid → ethyl acetate.

76. How to recognize solutions of the following substances using one reagent: water, ethylene glycol, formic acid, acetaldehyde, glucose. Write the equations of the corresponding reactions, indicate their type, the conditions for the course, describe the observations.

77. Solutions of glucose and sucrose are given. How to recognize them empirically? Describe your hypothesized observations and support them with reaction equations.

78. Solve the chain of transformations: maltose → glucose → → lactic acid → carbon dioxide.

79. The mass fraction of starch in potatoes is 20%. What mass of glucose can be obtained from 1620 kg of potatoes if the product yield is 75% of the theoretical one?

80. Solve chains of transformations:

1) CH 4 → X → CH 3 OH → Y → HCOOH → ethyl formate

2) CH 3 ─CH 2 ─CH 2 OH → CH 3 ─CH 2 ─CHO → CH 3 ─CH 2 ─COOH → →CH 3 ─CHBr─COOH → CH 3 ─CHBr─COOCH 3 → CH 2 =CH─COOCH 3

NaOH

Br2

NaOH

3-methylbutanol X 1 X 2 X 3

81. How, using the minimum number of reagents, to recognize substances in each pair: a) ethanol and methanal, b) acetaldehyde and acetic acid, c) glycerin and formaldehyde, d) oleic acid and stearic acid. Write the reaction equations, indicate their type, name the products, describe the observations.

82. Solve chains of transformations:

1) methane → ethyn → ethanal → ethanoic acid → acetic acid methyl ester → carbon dioxide

2) starch→glucose→ethanol→ethylene→polyethylene

3) calcium carbide → acetylene → benzene → chlorobenzene → phenol → 2,4,6-tribromophenol

83. Name the substances and indicate the class of oxygen-containing organic substances:

A) CH 3 ─ C ─CH 2 ─CHO b) CH 3 ─CH 2 ─COOCH 3