Task number 3
From the proposed list of compounds, select those that contain carbon atoms in sp 3 hybridization. There can be any number of correct answers.
Answer: 345
Task number 4
From the proposed list of compounds, select those that do not contain carbon atoms in sp 3 hybridization. There can be any number of correct answers.
2) vinylacetylene
3) cyclopropane
5) ethylbenzene
Answer: 24
Task number 6
From the proposed list of substances, select those that do not react with benzene. There can be any number of correct answers.
1) hydrogen bromide
3) nitric acid
4) caustic potash
Answer: 124
Task number 7
From the proposed list of substances, select those that react with benzene, but do not react with ethylene. There can be any number of correct answers.
1) propylene
4) chlorobutane
5) potassium nitrate
Answer: 14
Task number 8
From the proposed list of substances, select those that do not react with benzene, but react with propylene. There can be any number of correct answers.
2) potassium permanganate
3) bromine water
4) lime water
5) hydrogen chloride
Answer: 235
Task number 9
From the proposed list of substances, select those that react with benzene and cyclohexane. There can be any number of correct answers.
1) hydrogen
3) oxygen
5) nitric acid
Answer: 345
Task number 11
From the proposed list of substances, select those that react with toluene, but do not react with methane. There can be any number of correct answers.
1) oxygen
2) hydrogen
5) potassium permanganate
Answer: 25
Task number 12
From the proposed list of substances, select those that react with both toluene and cyclohexene. There can be any number of correct answers.
2) potassium permanganate
3) hydrogen
4) bromine water
5) 3-phenylpropene
Answer: 23
Task number 13
From the proposed list of substances, select those that do not react with toluene, but react with methylcyclopropane. There can be any number of correct answers.
3) hydrogen
4) bromide
Answer: 4
Task number 15
From the proposed list of substances, select those that do not react with toluene and isobutane. There can be any number of correct answers.
2) formaldehyde
5) nitric acid
Answer: 123
Task number 16
3) hydrogen bromide
4) oxygen
Answer: 135
Task number 17
From the proposed list of substances, select those that react with styrene, but do not react with benzene. There can be any number of correct answers.
1) potassium permanganate
2) hydrogen
3) oxygen
4) caustic soda
5) hydrogen chloride
Answer: 15
Task number 18
From the proposed list of substances, select those that react with styrene, but do not react with cumene. There can be any number of correct answers.
1) hydrogen
4) hydrogen iodine
Answer: 4
Task #19
From the proposed list of substances, select those that react with styrene, but do not react with ethane. There can be any number of correct answers.
1) nitric acid
3) hydrogen bromide
4) sodium permanganate
Answer: 345
Task number 20
From the proposed list of substances, select those that react with cumene, but do not react with benzene. There can be any number of correct answers.
1) oxygen
3) potassium permanganate
4) hydrogen
Answer: 3
Task number 21
5) 2-methylbutane
Answer: 14
Task #22
From the proposed list of substances, select those that react with an acidified solution of potassium permanganate when heated. There can be any number of correct answers.
4) ethylbenzene
Answer: 124
Task #23
From the proposed list of substances, select those that do not react with an acidified potassium permanganate solution when heated. There can be any number of correct answers.
1) 1,2-dimethylbenzene
2) isopropylbenzene
3) phenylethene
5) isobutylene
Answer: 4
Task #24
From the proposed list of substances, select those that discolor bromine water. There can be any number of correct answers.
1) 2-phenylpropene
2) methylcyclopropane
3) ethylbenzene
5) propylene
Answer: 1245
Task #25
From the proposed list of substances, select those that do not discolor bromine water. There can be any number of correct answers.
1) 2-methyl-3-phenylpropane
2) 3-phenylpropene
3) isopropylbenzene
4) tert-butylbenzene
5) vinylbenzene
Answer: 134
Task #26
From the proposed list of substances, select those that can enter into a radical substitution reaction with bromine. There can be any number of correct answers.
3) 1,4-diethylbenzene
4) phenylmethane
5) cyclopentane
Answer: 2345
Task number 27
From the proposed list of substances, select those that cannot enter into a radical substitution reaction with chlorine. There can be any number of correct answers.
Answer: 35
Task #28
2) benzyl bromide
4) benzoic acid
5) m-bromotoluene
Answer: 24
Task #29
From the proposed list of substances, select those that can be obtained from benzene in one stage. There can be any number of correct answers.
1) benzoic acid
3) phenylethane
4) cyclopentane
Answer: 235
Task number 30
1) phenylethane
3) 1,2-dibromo-1-phenylethane
4) 1-phenylethanediol-1,2
5) styrene butadiene rubber
Answer: 1345
Task number 31
From the proposed list of substances, select those that can be obtained from cumene in one stage. There can be any number of correct answers.
1) benzoic acid
3) 2-bromo-2-phenylpropane
5) potassium benzoate
Answer: 1345
Task #32
From the proposed list of substances, select those that can be oxidized to benzoic acid. There can be any number of correct answers.
2) ethylbenzene
4) 1,3-dimethylbenzene
Answer: 235
Task number 33
From the proposed list of substances, select those that can be obtained from ethylbenzene in one step. There can be any number of correct answers.
4) 1-bromo-1-phenylethane
5) carbon monoxide
Answer: 145
Task number 34
From the proposed list of substances, select those that can be obtained from toluene in one step. There can be any number of correct answers.
1) benzoic acid
3) chlorobenzene
4) P-nitrotoluene
5) 1,4-dimethylbenzene
Answer: 145
Task #35
From the proposed list of substances, select those that can be obtained from styrene in one stage. There can be any number of correct answers.
1) phenylethane
2) 1-bromo-1-phenylethane
3) 1,1-dibromo-1-phenylethane
4) benzoic acid
5) carbon dioxide
Answer: 1245
Task #36
Choose two incorrect statements from the given list.
1) styrene reacts with both bromine water and hydrogen
2) to obtain cumene in one stage, benzene and propylene can be used as starting materials.
3) when benzene is oxidized under severe conditions, benzoic acid can be obtained.
4) in the interaction of propylene and benzene in the presence of a catalyst, the main product is n-propylbenzene.
5) Vinylbenzene is used in the production of certain types of rubber.
Answer: 34
Task #37
1) carbon atoms in the benzene molecule are in different states of orbital hybridization
2) when styrene is added to a hot acidified solution of potassium permanganate, a discoloration of the liquid is observed.
3) the reaction of toluene with bromine water leads to instant discoloration of the solution.
4) To obtain cumene, both isopropyl chloride and 1-chloropropane can be used as starting materials.
5) Cumene and styrene are able to polymerize and give copolymers with butadiene.
Answer: 24
Task #38
1) When a benzene sample is ignited in air, carbon dioxide and water are predominantly formed.
2) To obtain phenylmethane in one stage, methane and chlorobenzene can be used in the presence of aluminum chloride.
3) The interaction of ethylbenzene with a hot acidified solution of potassium permanganate leads to the formation of phenylethanoic acid.
4) When receiving toluene by catalytic reforming, you can take as starting materials n-heptane and methylcyclohexane.
5) Benzene, toluene and ethylbenzene can interact both with bromine in the presence of iron and with a nitrating mixture.
Answer: 23
Task #39
Choose 2 true statements from the given list.
1) Cumene, toluene and styrene are described by the general formula C n H 2 n -6 .
2) During the hydrogenation of benzene and toluene under harsh conditions, respectively, predominantly n-hexane and n-heptane.
3) Toluene and ethylbenzene can react radically with chlorine and bromine in the light.
4) Styrene and benzene can be oxidized to benzoic acid with a hot, acidified potassium permanganate solution.
5) When styrene reacts with a solution of bromine in an organic solvent and water in the presence of sulfuric acid, 1,2-dibromo-1-phenylethane and 1-phenylethanol are formed, respectively.
Answer: 35
Task #40
Choose 2 incorrect statements from the given list.
1) Both benzene and styrene are capable of hydrogenating to form cycloalkanes
2) When reacting bromomethane with benzene in the presence of aluminum chloride, toluene can be obtained
3) The interaction of benzene with a nitrating mixture can lead to a mixture of nitrobenzene and 1,4-dinitrobenzene
4) The interaction of benzoic acid with the nitrating mixture leads mainly to the formation m-nitrobenzoic acid
5) When toluene is brominated in the presence of iron, a mixture is formed, consisting mainly of 2- and 3-bromotoluene
Answer: 35
Task number 41
What judgments about properties aromatic hydrocarbons are true? There can be any number of correct answers.
1) These hydrocarbons react under certain conditions with both ethylene and ethane.
2) Benzene, toluene and styrene are homologues relative to each other.
3) Styrene and ethylbenzene can be converted into benzoic acid in one step.
4) The benzene molecule is flat and contains a conjugated system, which includes 4 π-bonds.
5) Benzene can be obtained in one step from n-hexane and potassium benzoate.
Answer: 35
Task #42
What judgments about the properties of benzene are not correct? There can be any number of correct answers.
1) Nitration of benzene is carried out under the action of concentrated nitric acid in the presence of a mercury cation.
2) For the chlorination and bromination of benzene, aluminum chloride can be used as a catalyst.
3) When benzene is oxidized with a hot neutral solution of potassium permanganate, potassium benzoate is formed.
4) Hydrogenation of benzene can lead to the formation n-hexane or cyclohexane depending on the reaction conditions.
5) Alkylation of benzene can be carried out using alkenes and haloalkanes as reagents.
Answer: 134
Task number 43
What judgments about the properties of toluene are correct? There can be any number of correct answers.
1) Toluene and ethylbenzene are related to each other as homologues.
2) Toluene can react with both chlorine and hydrogen chloride.
3) Catalytic hydrogenation of toluene leads to 2-methylhexane.
4) Benzyl bromide and benzoic acid can be obtained from toluene in one step.
5) By reacting toluene with water, benzyl alcohol can be obtained.
Answer: 14
Task #44
What judgments about the properties of cumene are correct? There can be any number of correct answers.
1) When cumene is brominated in the light, a tertiary halogen derivative is formed.
2) Cumol and n-butylbenzene are homologues.
3) Cumene can be obtained from propylene and benzene.
4) When cumene is oxidized under severe conditions, one organic product is formed.
5) Cumene and 2-phenylpropane are isomers of each other.
Answer: 134
Task #45
What judgments about the properties of styrene are correct? There can be any number of correct answers.
1) Styrene can be incorporated into rubber
2) Styrene can discolor bromine water and sodium permanganate solution
3) With partial hydrogenation of styrene, toluene can be obtained
4) Styrene and allylbenzene are homologues relative to each other
5) 1-bromo-1-phenylethane and 2-phenylethanol can be converted into styrene in one step
Answer: 1245
Task #46
Answer: 432
Task #47
Match the name of the substance with its molecular formula.
Write in the table the selected numbers under the corresponding letters.
Answer: 312
Task #48
Match the name of the substance with its molecular formula.
Write in the table the selected numbers under the corresponding letters.
Answer: 244
Task #49
Establish a correspondence between the name of the substance and the product of its interaction with one equivalent of bromine in the presence of aluminum chloride.
Write in the table the selected numbers under the corresponding letters.
Answer: 321
Task number 50
Establish a correspondence between the name of the substance and the product of its interaction with one equivalent of bromine without a catalyst and irradiation.
Write in the table the selected numbers under the corresponding letters.
Answer: 424
Task number 51
Establish a correspondence between the name of the substance and the product of its interaction with one equivalent of chlorine under conditions of radical substitution.
Write in the table the selected numbers under the corresponding letters.
Answer: 431
Task number 52
Establish a correspondence between the name of the substance and the aromatic hydrocarbon that can be obtained from it in one step.
Write in the table the selected numbers under the corresponding letters.
Answer: 231
Task number 53
Establish a correspondence between a pair of substances and a reagent with which they can be distinguished.
Write in the table the selected numbers under the corresponding letters.
Answer: 341
Task number 54
Match a pair of substances with a reagent with which both of them can react.
| SUBSTANCE | REAGENT |
| A) ethylene and styrene |
Lab
"Chemical Properties of Arenes".
Goals : highlight the main Chemical properties arenes;
Tasks : give the concept of the definition of arenes, determine which reactions arenes can enter into, highlight the main chemical properties of arenes:
Lead time: 1 hour
The order of the work.
Write down the topic of the laboratory lesson;
Write down the goals and objectives of the lesson;
Complete the practical part of the lesson;
Answer questions to consolidate the studied material of the laboratory lesson;
Theoretical part.
Arene substitution reactions.
The core of arenes has a mobileπ - a system that is affected by electrophilic reagents. Arenes are characterized by electrophilic substitution, which can be represented as follows:
The electrophilic particle is attracted toπ - ring system, then a strong bond is formed between the reagentXand one of the carbon atoms, while the unity of the ring is broken. To restore aromaticity, a proton is ejected, and 2 electronsS-Ngo over to the π-system of the ring.
1. Halogenation occurs in the presence of catalysts - anhydrous and bromides, :
2. Nitration of arenes. Benzene reacts very slowly with concentrated with strong heating. But if you add , then the reaction proceeds very easily:
3. Sulfonation proceeds under the influence of 100% - sulfuric acid - oleum:
4. Alkylation . As a result, the chain is elongated, the reaction proceeds in the presence of a catalyst - aluminum chloride:
Arene addition reactions.
1. Hydrogenation (with catalysts) of arenes:
2. Radical halogenation in the interaction of benzene vapor and strong UV radiation. The result is a solid productWith 6
H 6
Cl 6
:
3. air. The reaction proceeds at vanadium(V) oxide and 400°C:
Benzene homologues have a number of differences - for their products I am the initial substituent in the ring:
Substitution in the ring is possible only in the presence of a catalyst (iron and aluminum chloride), the substitution proceeds in the ortho and para positions with respect to the alkyl radical:
If strong oxidizing agents ( ), then the alkyl chain is destroyed and benzoic acid is formed:
Practical part.
An organic substance whose molecular formula is C7H8 belongs to the homologous series
1) methane 2) ethylene 3) benzene 4) acetylene
Toluene is a representative homologous series
1) phenol 2) benzene 3) methanol 4) styrene
The homologue of benzene is a substance whose formula is
1) С8Н18 2) С8Н10 3) С8Н16 4) С8Н14
A benzene isomer is a compound whose formula is
1) C6H5−CH=CH−CH3 2) CH3−CH−C≡C−CH−CH3
3) CH2=CH−CH2−CH2−CH2−CH3 4) CH2=CH−C≡C−CH=CH2
Toluene and ethylbenzene are
1) homologues 2) structural isomers
3) geometric isomers 4) the same substance
The representative of the homologous series of benzene is
1) toluene 2) phenol 3) styrene 4) methanol
A compound in which all carbon atoms are sp2 hybridized is
1) ethylbenzene 2) benzene 3) methylcyclohexane 4) butene-1
In a chain of transformations
the final product "X3" has the formula
2)
3)
4)
Write the reaction equations that can be used to carry out the following transformations:
Benzene can be converted to cyclohexane by the reaction
1) hydrogenation 2) hydration 3) dehydrogenation 4) dehydration
The formation of benzene occurs as a result of trimerization
1) ethene 2) ethane 3) ethanol 4) ethine
Benzene can be obtained from acetylene in one step by the reaction
1) dehydrogenation 2) trimerization 3) hydrogenation 4) hydration
1) does not burn in air 2) reacts with KMnO4 solution
3) enters into hydrogenation reactions 4) reacts with bromine in the presence of a catalyst
Benzene is able to interact with each of the two substances:
1) H2 and HBr 2) HNO3 and KMnO4 3) C2H5Cl and HNO3 4) CH3OH and C2H6
Benzene undergoes a substitution reaction with
1) bromine and nitric acid 2) oxygen and sulfuric acid
3) chlorine and hydrogen 4) nitric acid and hydrogen
Benzene interacts with each of two substances:
1) C2H5OH and N2 2) HNO3 and HBr 3) H2O and O2 4) CH3Cl and Br2
In the scheme of transformations C6H14 → X → C6H5CH3, the substance "X" is
1) C6H5OH 2) C6H10 3) C6H13COOH 4) C6H6
To obtain cyclohexane from benzene, the reaction is used
1) dehydrogenation 2) halogenation 3) hydrogenation 4) hydration
Chlorobenzene is formed when benzene reacts with
1) chlorine (UV) 2) chlorine (FeCl3) 3) hydrogen chloride 4) chloromethane
Benzene does not interact with
1) nitric acid 2) bromine 3) hydrogen bromide 4) oxygen
Each of the two substances interacts with toluene:
1) CH3OH and Ag2O 2) KMnO4 and H2 3) Cl2 and NaOH 4) HNO3 and CH3OCH3
In the scheme of transformations C6H6→X1→X2→+ Cl-substances “X1” and “X2”, respectively, are:
1) C6H5NO2andC6H5Cl 2) C6H5OHandC6H5Cl
3) C6H5OHandC6H5NO2 4) C6H5NO2andC6H5NH2
Hexachlorocyclohexane is formed as a result of the interaction
1) chlorine and benzene 2) chlorine and cyclohexane
3) hydrogen chloride and benzene 4) chlorine and hexane
Toluene, unlike benzene,
1) undergoes hydrogenation 2) is oxidized by atmospheric oxygen
3) reacts with chlorine (in the presence of AlCl3) 4) oxidizes with potassium permanganate solution
The similarity of the chemical properties of benzene and saturated hydrocarbons is manifested in the reaction
1) С6Н6 + 3H2 → C6H12 2) С6Н6 + С2H4 → C6H5 – C2H5
3) С6Н6 + 3Сl2 → C6H6Cl6 4) С6Н6 + Br2 → C6H5Br + НBr
Hydrogen reacts with benzene to form
1) toluene 2) hexanol-1 3) acetylene 4) cyclohexane
Are the following statements about the properties of aromatic hydrocarbons correct?
A. Benzene discolors potassium permanganate solution.
B. Toluene enters into a polymerization reaction.
1) only A is true 2) only B is true 3) both judgments are correct 4) both judgments are wrong
In the scheme methane → X → benzene, compound "X" is
1) chloromethane 2) ethylene 3) hexane 4) ethyne
Toluene can be formed during aromatization (dehydrocyclization)
Benzene can be obtained from the trimerization reaction
1) cyclohexane 2) ethane 3) ethylene 4) acetylene
Both ethylene and benzene are characterized by:
1) hydrogenation reaction 2) the presence of only π-bonds in molecules
3) sp2 hybridization of carbon atoms in molecules 4) high solubility in water
5) interaction with an ammonia solution of silver oxide (I) 6) combustion in air
Toluene reacts with
1) hydrogen 2) water 3) zinc
4) nitric acid 5) hydrogen chloride 6) chlorine
Both acetylene and toluene are characterized by (-o):
1) polymerization reaction 2) sp2 hybridization of carbon atoms in a molecule
3) oxidation with potassium permanganate 4) halogenation reaction
Cycloalkanes (cycloparaffins, naphthenes) are cyclic saturated hydrocarbons, according to chemical structure close to alkanes. Contain only simple single sigma bonds (σ-bonds), do not contain aromatic bonds.
Cycloalkanes have a higher density and higher melting and boiling points than the corresponding alkanes. General formula their homologous series - C n H 2n.
Nomenclature and isomerism of cycloalkanes
The names of cycloalkanes are formed by adding the prefix "cyclo-" to the name of the alkane with the corresponding number: cyclopropane, cyclobutane, etc.
As with alkanes, the carbon atoms of cycloalkanes are in sp 3 hybridization.
In addition to the isomerism of the carbon skeleton, cycloalkanes are characterized by interclass isomerism with alkenes and spatial geometric isomerism in the form of the existence of cis- and trans-isomers.
Obtaining cycloalkanes
In industry, cycloalkanes are obtained in several ways:
Under laboratory conditions, cycloalkanes can be obtained by the dehalogenation reaction of dihaloalkanes.
Chemical properties of cycloalkanes
It is important to note that cyclopropane and cyclobutane enter into addition reactions, showing the properties of unsaturated compounds. For cyclopentane and cyclohexane, addition reactions are not characteristic, they mainly enter into substitution reactions.
© Bellevich Yury Sergeevich 2018-2020
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Physical properties
Benzene and its closest homologues are colorless liquids with a specific odor. Aromatic hydrocarbons are lighter than water and do not dissolve in it, but they easily dissolve in organic solvents - alcohol, ether, acetone.
Benzene and its homologues are themselves good solvents for many organic matter. All arenas burn with a smoky flame due to the high carbon content of their molecules.
The physical properties of some arenes are presented in the table.
Table. Physical properties of some arenas
|
Name |
Formula |
t°.pl., |
t°.bp., |
|
Benzene |
C 6 H 6 |
5,5 |
80,1 |
|
Toluene (methylbenzene) |
C 6 H 5 CH 3 |
95,0 |
110,6 |
|
Ethylbenzene |
C 6 H 5 C 2 H 5 |
95,0 |
136,2 |
|
Xylene (dimethylbenzene) |
C 6 H 4 (CH 3) 2 |
||
|
ortho- |
25,18 |
144,41 |
|
|
meta- |
47,87 |
139,10 |
|
|
pair- |
13,26 |
138,35 |
|
|
Propylbenzene |
C 6 H 5 (CH 2) 2 CH 3 |
99,0 |
159,20 |
|
Cumene (isopropylbenzene) |
C 6 H 5 CH(CH 3) 2 |
96,0 |
152,39 |
|
Styrene (vinylbenzene) |
C 6 H 5 CH \u003d CH 2 |
30,6 |
145,2 |
Benzene - low-boiling ( tkip= 80.1°C), colorless liquid, insoluble in water
Attention! Benzene - poison, acts on the kidneys, changes the blood formula (with prolonged exposure), can disrupt the structure of chromosomes.
Most aromatic hydrocarbons are life threatening and toxic.
Obtaining arenes (benzene and its homologues)
In the laboratory
1. Fusion of salts of benzoic acid with solid alkalis
C 6 H 5 -COONa + NaOH t → C 6 H 6 + Na 2 CO 3
sodium benzoate
2. Wurtz-Fitting reaction: (here G is halogen)
From 6H 5 -G+2Na + R-G →C 6 H 5 - R + 2 NaG
With 6 H 5 -Cl + 2Na + CH 3 -Cl → C 6 H 5 -CH 3 + 2NaCl
In industry
- isolated from oil and coal by fractional distillation, reforming;
- from coal tar and coke oven gas
1. Dehydrocyclization of alkanes with more than 6 carbon atoms:
C 6 H 14 t , kat→C 6 H 6 + 4H 2
2. Trimerization of acetylene(only for benzene) – R. Zelinsky:
3С 2 H2 600°C, Act. coal→C 6 H 6
3. Dehydrogenation cyclohexane and its homologues:
Soviet Academician Nikolai Dmitrievich Zelinsky established that benzene is formed from cyclohexane (dehydrogenation of cycloalkanes
C 6 H 12 t, cat→C 6 H 6 + 3H 2
C 6 H 11 -CH 3 t , kat→C 6 H 5 -CH 3 + 3H 2
methylcyclohexanetoluene
4. Alkylation of benzene(obtaining homologues of benzene) – r Friedel-Crafts.
C 6 H 6 + C 2 H 5 -Cl t, AlCl3→C 6 H 5 -C 2 H 5 + HCl
chloroethane ethylbenzene
Chemical properties of arenes
I. OXIDATION REACTIONS
1. Combustion (smoky flame):
2C 6 H 6 + 15O 2 t→12CO 2 + 6H 2 O + Q
2. Benzene under normal conditions does not decolorize bromine water and an aqueous solution of potassium permanganate
3. Benzene homologues are oxidized by potassium permanganate (discolor potassium permanganate):
A) in an acidic environment to benzoic acid
Under the action of potassium permanganate and other strong oxidants on the homologues of benzene, the side chains are oxidized. No matter how complex the chain of the substituent is, it is destroyed, with the exception of the a -carbon atom, which is oxidized into a carboxyl group.
Homologues of benzene with one side chain give benzoic acid:
Homologues containing two side chains give dibasic acids:
5C 6 H 5 -C 2 H 5 + 12KMnO 4 + 18H 2 SO 4 → 5C 6 H 5 COOH + 5CO 2 + 6K 2 SO 4 + 12MnSO 4 + 28H 2 O
5C 6 H 5 -CH 3 + 6KMnO 4 + 9H 2 SO 4 → 5C 6 H 5 COOH + 3K 2 SO 4 + 6MnSO 4 + 14H 2 O
Simplified :
C 6 H 5 -CH 3 + 3O KMnO4→C 6 H 5 COOH + H 2 O
B) in neutral and slightly alkaline to salts of benzoic acid
C 6 H 5 -CH 3 + 2KMnO 4 → C 6 H 5 COO K + K OH + 2MnO 2 + H 2 O
II. ADDITION REACTIONS (harder than alkenes)
1. Halogenation
C 6 H 6 + 3Cl 2 h ν → C 6 H 6 Cl 6 (hexachlorocyclohexane - hexachloran)
2. Hydrogenation
C 6 H 6 + 3H 2 t , PtorNi→C 6 H 12 (cyclohexane)
3. Polymerization
III. SUBSTITUTION REACTIONS – ionic mechanism (lighter than alkanes)
b) benzene homologues upon irradiation or heating
In terms of chemical properties, alkyl radicals are similar to alkanes. Hydrogen atoms in them are replaced by halogens by a free radical mechanism. Therefore, in the absence of a catalyst, heating or UV irradiation leads to a radical substitution reaction in the side chain. The influence of the benzene ring on alkyl substituents leads to the fact that the hydrogen atom is always replaced at the carbon atom directly bonded to the benzene ring (a-carbon atom).
1) C 6 H 5 -CH 3 + Cl 2 h ν → C 6 H 5 -CH 2 -Cl + HCl
c) benzene homologues in the presence of a catalyst
C 6 H 5 -CH 3 + Cl 2 AlCl 3 → (mixture of orta, pair of derivatives) +HCl
2. Nitration (with nitric acid)
C 6 H 6 + HO-NO 2 t, H2SO4→C 6 H 5 -NO 2 + H 2 O
nitrobenzene - smell almond!
C 6 H 5 -CH 3 + 3HO-NO 2 t, H2SO4→ With H 3 -C 6 H 2 (NO 2) 3 + 3H 2 O2,4,6-trinitrotoluene (tol, trotyl)
The use of benzene and its homologues
Benzene C 6 H 6 is a good solvent. Benzene as an additive improves the quality of motor fuel. It serves as a raw material for the production of many aromatic organic compounds - nitrobenzene C 6 H 5 NO 2 (solvent, aniline is obtained from it), chlorobenzene C 6 H 5 Cl, phenol C 6 H 5 OH, styrene, etc.
Toluene C 6 H 5 -CH 3 - a solvent used in the manufacture of dyes, drugs and explosives (trotyl (tol), or 2,4,6-trinitrotoluene TNT).
Xylene C 6 H 4 (CH 3) 2 . Technical xylene is a mixture of three isomers ( ortho-, meta- and pair-xylenes) - is used as a solvent and starting product for the synthesis of many organic compounds.
Isopropylbenzene C 6 H 5 -CH (CH 3) 2 serves to obtain phenol and acetone.
Chlorine derivatives of benzene used for plant protection. Thus, the product of substitution of H atoms in benzene with chlorine atoms is hexachlorobenzene C 6 Cl 6 - a fungicide; it is used for dry seed dressing of wheat and rye against hard smut. The product of the addition of chlorine to benzene is hexachlorocyclohexane (hexachloran) C 6 H 6 Cl 6 - an insecticide; it is used to control harmful insects. These substances refer to pesticides - chemical means of combating microorganisms, plants and animals.
Styrene C 6 H 5 - CH \u003d CH 2 polymerizes very easily, forming polystyrene, and copolymerizing with butadiene - styrene-butadiene rubbers.
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