List of substances that decolorize bromine water. Why does bromine water decolorize Examples of bromine water decolorization reactions
It is customary to write through such a formula - Br2, although it is in solution in the form of a mixture of two acids - HBrO (hypochlorous acid) and HBr. This compound has a yellow-orange color and a rather low freezing point. It is a strong oxidizing agent that is capable of oxidizing cations of such metals in an alkaline environment - Cr +3, Mn +3, Fe +2, Co + 2, Ni +3. The addition of Br 2 reduces the pH of the solution (pH), because bromine water contains free acids.
This is a chemically active substance that can interact with both inorganic and organic substances. Let's consider some chemical processes with this compound.
Discoloration of bromine water serves everything To carry out such an experiment, it is necessary to mix a small amount of any alkene or alkyne in a test tube with Br 2 . In the course of this reaction, bromine atoms are added at the site of the double or triple bond rupture. The disappearance of the yellow-orange color during this interaction is proof of the unsaturation of the hydrocarbon taken.
The chemical reaction "phenol - bromine water" is used to precipitate bromine-substituted compounds from solutions. If this interaction of substances is carried out in an anhydrous environment, then the formation of tribromophenol will take a couple of days. Therefore, a small amount of H 2 O is added as a catalyst.
Bromine water in the laboratory is prepared as follows: 250 ml of distilled water is added to 1 ml of bromine, while vigorously stirring. The prepared solution is stored in a tightly closed dark glass container. If the prepared Br 2 is stored in the light or in a light bottle, oxygen will be released due to the hypobromous acid content. Work on the preparation of the reagent is carried out in a fume hood. Since bromine itself is poisonous, and bromine water contains it, care must be taken when working with it.
It is also necessary to take into account the fact that when Br 2 gets on the skin, severe itching appears, and with prolonged exposure, ulcers can occur. If the substance has got on the skin, it should be washed with plenty of water, and then in case of a large wound surface or deep lesions of the epidermis, the skin is additionally lubricated with an ointment, which includes NaHCO 3 .
Bromine water is widely used in chemical analysis and synthesis of organic preparations. So, it is used in the production of bromine-containing drugs. And here you need to be careful, because. prolonged use of them can lead to a disease - bromism. The main symptoms are apathy, lethargy, the appearance of a skin rash. For faster removal of bromine ions from the body, a diet with a high salt content and plenty of fluids are followed. Bromine water is also used in the intermediate stages of the production of flame retardants - substances that protect against ignition. They impregnate fabrics, wood, building material.
Task number 1
Choose two statements that are true for acetylene
1) all carbon atoms in the state sp 2- hybridization
2) has structural isomers
3) is an unsaturated hydrocarbon
4) highly soluble in water
5) under normal conditions is a gas
Answer: 35
Task number 2
Choose two statements that are true for alkynes
1) are saturated hydrocarbons
2) enter into addition reactions
3) can exist in the form cis-, trance- isomers
5) decolorize bromine water
Answer: 25
Task number 3
1) have the general formula C n H 2n
2) carbon atoms in molecules are interconnected only by σ-bonds
3) react with sodium
4) react with bromine
5) can be obtained from dihaloalkanes
Answer: 45
Task number 4
Choose two statements that are true for ethine
1) poorly soluble in water
2) has interclass isomers
3) is the main component of natural gas
4) can be obtained by hydrolysis of calcium carbide
5) the molecule has a tetrahedral structure
Answer: 14
Task number 5
Choose two statements that are true for propyne.
1) enters into a substitution reaction without breaking the triple bond
2) during trimerization forms 1,3,5-trimethylbenzene
3) can be obtained by hydrolysis of aluminum carbide
4) is a liquid, under normal conditions
5) do not discolor the aqueous solution of potassium permanganate
Answer: 12
Task number 6
Choose two statements that are true for butin -1
1) enters into substitution reactions with OH
2) in the hydration reaction forms butanol-2
3) is formed during the dehydrogenation of butane
4) reacts with bromine water
5) is an isomer of isoprene
Answer: 14
Task number 7
Choose two statements that are true for butyn-1.
1) does not react with water
2) enters into substitution reactions with Cl
3) upon hydration, forms an aldehyde
4) is an isomer of divinyl
5) is able to attach only 1 mole of hydrogen
Answer: 24
Task number 8
Choose two statements that are true for both butyn-1 and butyn-2.
1) 1 mol of hydrocarbon during hydration can attach only 1 mol of water
2) are liquids under normal conditions
3) enter into substitution reactions with an ammonia solution of silver oxide
4) among the products of the reaction with an acidified solution of KMnO 4 there are carboxylic acids
5) can be obtained from 2-chlorobutane in one step
Answer: 14
Task number 9
Choose two statements that are true for butyn-1 and butyn-2.
1) when hydrated, they form the same substance
2) molecules have a flat structure
3) can be obtained from 1,1-dibromobutane and 2,3-dibromobutane, respectively
4) enter into substitution reactions with sodium
5) can exist in the form cis-, trance-isomers
Answer: 13
Task number 10
Choose two statements that are true for all alkynes.
1) discoloration of bromine water
2) react with an ammonia solution of silver oxide
3) the presence of structural isomers
4) highly soluble in water
5) have the general formula of the homologous series C n H 2n-2
Answer: 15
Task number 11
Choose two statements that are true for all alkynes.
1) molecules have a flat structure
2) all carbon atoms in molecules are connected by π bonds
3) refer to unsaturated hydrocarbons
4) enter into a dehydration reaction
5) poorly soluble in water
Answer: 35
Task number 12
Choose two statements that not valid for alkynes.
1) can exist in the form cis-, trance- isomers
2) burn in air
4) enter into hydrogenation reactions
5) when interacting with an aqueous solution of potassium permanganate form glycols
Answer: 15
Task number 13
Choose two statements that are true for both ethylene and acetylene.
1) belong to the class of alkenes
2) under normal conditions are gases
3) decolorize bromine water
5) have the general formula of the homological series C n H 2 n
Answer: 23
Task number 14
Choose two statements that are true for both ethane and acetylene
1) decolorize an aqueous solution of potassium permanganate
2) poorly soluble in water
3) form explosive mixtures with air
Task number 15
Choose two statements that are true for both propane and propyne.
1) enter into hydration reactions
2) capable of being oxidized by oxygen
3) have interclass isomers
4) react with bromine
5) all carbon atoms in molecules are in the state sp 3- hybridization
Answer: 24
Task #24
From the proposed list, select two substances that are structural isomers of pentyn-2.
1) 3-methylbutin-1
2) pentyn-1
3) 3-methylpentine-1
4) hexine-2
5) pentene-1
Answer: 12
Task #25
From the proposed list, select two substances that are structural isomers of pentyn-1.
1) pentadiene-1,3
2) hexadiene-1,3
3) butadiene-1,3
5) 3-methylbutin-1
Answer: 15
Task #26
From the proposed list, select two substances that have carbon atoms in the state in the state sp-hybridization.
1) isoprene
2) acetylene
5) butadiene-1,3
Answer: 24
Task number 27
From the proposed list, select two substances that have a carbon atom in the state sp- hybridization
1) divinyl
2) propylene
5) butadiene-1,2
Answer: 45
Task #28
From the suggested list of compounds, select two substances with which ethyne can react.
2) potassium hydroxide
3) ammonia solution of silver oxide
4) bromine water
5) sodium chloride
Answer: 34
Task #29
From the proposed list of compounds, select two substances with which propyne can react.
1) copper (II) oxide
2) potassium permanganate solution
3) potassium hydroxide
Answer: 25
Task number 33
From the proposed list of compounds, select two substances that can enter into a hydrohalogenation reaction.
2) cyclopropane
3) cyclopentane
5) methyl propane
Answer: 24
Task number 34
From the proposed list of compounds, select two substances that can enter into an oligomerization reaction.
3) acetylene
4) cyclopentane
5) methylcyclohexane
Answer: 13
Task #35
From the proposed list of compounds, select two substances that not can enter into a hydrohalogenation reaction.
2) cyclopropane
3) 1,2-dimethylcyclopentane
Answer: 35
Task #40
2) hydrogen
4) hydrogen chloride
5) oxygen
Answer: 15
Task number 41
From the proposed list of compounds, select two substances with which both acetylene and ethane can react.
1) bromine water
3) oxygen
4) potassium permanganate solution
5) ammonia solution of silver oxide
Answer: 23
Task #42
From the proposed list of compounds, select two substances with which both propyne and propene can react
1) sodium hydroxide
2) hydrogen bromide
3) bromine water
5) cyclopentane
Answer: 23
Task #44
From the proposed list of compounds, select two substances with which both propyne and propane can react
1) bromine water
2) potassium permanganate
3) oxygen
4) hydrogen
Answer: 35
Task #47
From the proposed list of reactions, select two that can be used to synthesize acetylene.
2) CH 3 Cl + H 2 O
4) CH 2 Cl-CH 2 Cl + 2NaOH
5) CH 2 \u003d CH 2 + H 2
Answer: 14
Task #48
From the proposed list of reactions, select two such that can be used to obtain propyne.
1) NaC≡C-CH 3 + CH 3 Cl
2) NaC≡C-CH 3 + HCl
3) CH 2 \u003d CH-CH 3 + H 2
4) CH 2 Cl-CHCl-CH 3 + 2KOH (alcohol)
5) CH 2 Cl-CHCl-CH 3 + 2KOH (aq)
Answer: 24
Task #49
1,2-dichloroethane acetylene silver acetylenide
3) KOH (aqueous solution)
4) OH
5) KOH (alcohol solution)
Answer: 54
Task number 50
The following scheme of transformations of substances is presented:
1,2-dichloropropane X dimethyl ketone
Determine which of the given substances are substances X and Y
2) H 2 C \u003d CH-CH 3
4) HC≡C-CH 3
Answer: 41
Task number 51
The following scheme of transformations of substances is presented:
acetylene X Y
1) 1,2-dichloroethane
4) acetaldehyde
5) 1,1-dichloroethane
Answer: 53
Task number 52
The following scheme of transformations of substances is presented:
calcium carbide X Y
Determine which of the given substances are substances X and Y
5) HC≡C— HC=CH 2
Answer: 34
Task number 53
The following scheme of transformations of substances is presented:
sodium acetylenide acetylene Y
Determine which of the given substances are substances X and Y.
1) hydrogen
2) 1,3,5-trimethylbenzene
4) hydrogen bromide
5) chloromethane
Answer: 43
Task number 54
The following scheme of transformations of substances is presented:
NaC≡C-CH 3 X potassium acetate
Determine which of the given substances are substances X and Y
2) KMnO 4 (H 2 SO 4)
3) HC≡C-CH 2 -CH 3
4) H 3 C-C≡C-CH 3
Answer: 45
Alkynes. Compliance tasks.
Task number 1
Establish a correspondence between the name of the substance and the class/group of organic compounds to which this substance belongs:
| BUT | B | AT | G |
Answer: 2134
Task number 2
Write in the table the selected numbers under the corresponding letters.
| BUT | B | AT | G |
Answer: 5335
Task number 3
Establish a correspondence between the formulas of substances and the reagent with which they can be distinguished: for each position indicated by a letter, select the corresponding position indicated by a number
Write in the table the selected numbers under the corresponding letters.
| BUT | B | AT | G |
Answer: 3434
Task number 4
Establish a correspondence between the hydrocarbon formula and the main product of its interaction with hydrogen chloride at a molar ratio of 1:1: for each position indicated by a letter, select the corresponding position indicated by a number.
Write in the table the selected numbers under the corresponding letters.
| BUT | B | AT | G |
Answer: 4612
Task number 5
Establish a correspondence between the formula of alkyne and the main product of its interaction with an excess of hydrogen bromide: for each position indicated by a letter, select the corresponding position indicated by a number.
Write in the table the selected numbers under the corresponding letters.
| BUT | B | AT | G |
Answer: 4561
Task number 6
Establish a correspondence between the name of the alkyne and the product of its interaction with water: for each position indicated by a letter, select the corresponding position indicated by a number.
Write in the table the selected numbers under the corresponding letters.
| BUT | B | AT | G |
Answer: 6433
Task number 7
Establish a correspondence between the name of an organic substance and the product of its interaction with alcoholic solution of alkali : for each position indicated by a letter, select the corresponding position indicated by a number.
Write in the table the selected numbers under the corresponding letters.
| BUT | B | AT | G |
Answer: 6153
Task number 8
Establish a correspondence between dihaloalkane and the product of its interaction with alcoholic solution of alkali : for each position indicated by a letter, select the corresponding position indicated by a number.
| REAGENTS | INTERACTION PRODUCT |
| A) 1,2-dichloroethane |
1)
C6H6
2)
C5H8
3)
C6H14
4)
C6H12
2. The C≡C bond length and the bond angle in alkyne molecules, respectively, are
1)
180˚ and 0.154 nm
3)
120˚ and 0.134 nm
2)
180˚ and 0.120 nm
4)
109˚28′ and 0.154 nm
3. KMnO4 solution decolorizes both substances in the series
1)
propine and propane
3)
acetylene and ethylene
2)
butadiene-1,3 and butane
4)
butylene and isobutane
4. As a result of the Kucherov reaction,
1)
ethanol
2)
ethane
3)
ethanal
4)
ethanediol-1,2
5. Acetylene is produced in industry using
1)
hydrolysis of calcium carbide
3)
oil distillation
2)
methane pyrolysis
4)
ethene hydrogenation
6. Ethine can be distinguished from ethane by
1)
litmus
3)
copper(II) hydroxide
2)
aqueous solution of alkali
4)
bromine water
7. Which of the following statements about propyne and its properties are correct?
A. The propyne molecule contains a tetrahedral fragment of atoms.
B. Propyne can be distinguished from propane using an aqueous solution of potassium permanganate.
1)
only A is correct
2)
only B is correct
3)
both statements are true
4)
both statements are wrong
8. In the scheme of transformations
CaC2 X1 X2
substances X1 and X2 are respectively
1)
C2H4 and C2H5Cl
3)
C2H2 and CH2Cl-CH2Cl
2)
C2H2 and CH2=CHCl
4)
CH4 and CH3Cl
9. Propyne is able to react with each of the substances indicated in the row
1)
KOH, C6H6, Br2
4)
H2, O2, Na
2)
Cu, H2, H2O
5)
KMnO4, CH4, HBr
3)
Cl2, HCl, OH
6)
H2O, Cl, Cl2
B. CH3 - C \u003d CH.
D. CH3 - C \u003d C - CH2 - CH3.
2. The first member of the homologous series of alkynes:
B. Propin.
3. Pentin-1 isomer is:
A. Penten-1.
B. 2-Methylbutane.
B. 3-Methylbutin-1.
D. 3-Methylpentine-1.
4. The bond between carbon atoms in the acetylene molecule:
A. Single.
B. Triple.
B. Double.
G. One and a half.
5. The formula of the substance, which is characterized by the hydrogenation reaction:
6. Method for obtaining butyne-1.
A. Dehydrogenation of butene-1.
B. Chlorination of methane.
B. Dehydrogenation of propane.
D. Hydration of butene-1.
7. Raw materials for the industrial production of polyvinyl chloride:
A. Acetylene. B. Chloroethane.
B. Ethylene. G. Butadiene-1,3.
8. Bromine water becomes colorless when a substance is passed through it, the formula of which is:
D. C4H10. 9. Catalyst in the Kucherov reaction:
A. Sulfuric acid.
B. Aluminum chloride.
B. Mercury sulfate (II).
G. Platinum.
10. The formula of a hydrocarbon, upon complete combustion of 1 mol of which 4 mol of carbon monoxide (IV) and 3 mol of water are formed: A. С4Н8. B. C4H10. B. C2H6. D. C4H6. Part B. Free Answer Tasks
11. What is the color and marking of steel cylinders used for the storage of methane and acetylene?
12. Derive the formula of a hydrocarbon, 2.24l of which (n.o.) has a mass of 4g.
13. Make the reaction equations according to the given scheme: calcium carbonate => calcium carbide => acetylene. Specify the conditions for their implementation.
1. Know the general formula of alkanes, formulas and names of substances of the homologous series of alkanes (up to octane);2. Know the definitions: homologues, homologous series, isomers, isomerism. Be able to write formulas of isomers, determine the type of isomerism.
Write isomer formulas for C4H10 and for C4H8.
3. Know the chemical properties of alkanes, be able to write reaction equations.
4. Know the general formula of alkenes, formulas and names of substances of the homologous series of alkenes (up to octene)
5. Know the chemical properties of alkenes, be able to write reaction equations
6. Application of alkanes and alkenes
7. Know the general formula of alkynes and alkadienes (up to C7)
8. Know the chemical properties of alkynes, be able to write reaction equations.
9. Know the general formula of benzene, its chemical properties, application
Alkynes (otherwise acetylenic hydrocarbons) are hydrocarbons containing a triple bond between carbon atoms, with the general formula CnH2n-2. The carbon atoms in the triple bond are in a state of sp - hybridization.
Reaction of acetylene with bromine water
The acetylene molecule contains a triple bond, bromine destroys it and joins the acetylene. Terabromomethane is formed. Bromine is consumed in the formation of tetrabromoethane. Bromine water (yellow) - discolors.
This reaction proceeds at a lower rate than in the series of ethylene hydrocarbons. The reaction also proceeds in steps:
HC ≡ CH + Br 2 → CHBr = CHBr + Br 2 → CHBr 2 - CHBr 2
acetylene → 1,2-dibromoethane → 1,1,2,2-tetrabromoethane
The decolorization of bromine water proves the unsaturation of acetylene.
The reaction of acetylene with a solution of potassium permanganate
In a solution of potassium permanganate, acetylene is oxidized, and the molecule breaks at the site of the triple bond, the solution quickly becomes colorless.
3HC ≡ CH + 10KMnO 4 + 2H 2 O → 6CO 2 + 10KOH + 10MnO 2
This reaction is a qualitative reaction for double and triple bonds.
The reaction of acetylene with an ammonia solution of silver oxide
If acetylene is passed through an ammonia solution of silver oxide, the hydrogen atoms in the acetylene molecule are easily replaced by metals, since they have high mobility. In this experiment, hydrogen atoms are replaced by silver atoms. Silver acetylenide is formed - a yellow precipitate (explosive).
CH ≡ CH + OH → AgC≡CAg↓ + NH 3 + H 2 O
This reaction is a qualitative reaction for a triple bond.
3) CH3 O CH3
4) CH3COO CH3
3. Specify the compound containing the carboxyl group:
1) aromatic alcohol
2) aldehyde
3) simple ether
4. Specify the compound containing the carbonyl group:
1) aromatic alcohol
2) aldehyde
3) simple ether
4) unsaturated polybasic acid
5.Give a name to the connection: O
CH3 - CH - CH - C
1) 2-methyl-3-bromobutanol-1
2) 2-bromo-3-methylbutanal
3) 2-methyl-3-bromobutanal
4) 2-bromo-3-methylpropanal
6. Reaction CH3CHO+Ag2O CH3COOH+2 Ag:
1) Polycondensation
2) Esterification
3) "silver mirror"
4) Kucherova
7. The functional group of carboxylic acids is called:
1) Carbonyl
2) Hydroxyl
3) Carboxyl
4) ester
8. Acetic acid does not react with the following metal:
9. What is the name of the aldehyde:
1) 2-Methyl-3-propylbutanal;
2) 2,3-dimethylhexanal;
3) 4,5-dimethylhexanal;
4) 2-methyl-2-propylbutanal
10. Specify the general formula of carbohydrates:
11. Indicate the carbohydrate that is the main part of wood:
1) Starch
2) Cellulose
4) Maltose
12. Specify the formula of fructose:
13. Pentose, which is part of DNA, is:
1) Glucose
2) Fructose
4) Deoxyribose
14. Milk sugar is a disaccharide:
1) Sucrose
2) Maltose
3) Lactose
4) Galactose
15. Beet or cane sugar is a disaccharide:
1) Maltose
2) Sucrose
3) Galactose
4) Lactose
16. Malt Sugar:
1) Galactose
2) Sucrose
3) Lactose
4) Maltose
17. In plant cells, starch performs the following function:
1) Transfer of hereditary information
2) Supply of nutrients
3) Construction and structural
4) Catalyst for biological processes
18. In plant cells, cellulose performs the following function:
1) Supply of nutrients
2) Catalyst of biological processes
3) Construction and structural
4) Transfer of hereditary information
19. Give a name to the connection:
CH3 - CH - CH - CH3
1) 3-methylbutanol-2 3) 3-methylpropanone-2
2) 2-methylbutanol-3 4) 2-methylpropanal-2
20. Write the equation for a chemical reaction and give it a name:
R1 - C + HO - R2 ↔
1) hydration 3) attachment
2) esterification reaction 4) substitution
Among the characteristics listed below, select those that, as a rule, relate to liquid fats - oils:
1) They are of plant origin
2) They are of animal origin
3) Highly soluble in water
4) Highly soluble in organic solvents
7) Discolor bromine water
8) Are esters of glycerol
Give your answer as a sequence of numbers in ascending order.
B-2 Match a fat feature with an example of a fat that matches that feature. Give your answer as a sequence of numbers corresponding to letters in alphabetical order:
CHARACTERISTIC:
A) solid fat of vegetable origin
B) solid fat of animal origin
C) liquid fat of animal origin
D) liquid fat of vegetable origin
1) Linseed oil
2) Butter
3) Fish oil
4) Palm oil
Hello. Help me please. 1) Specify the number of isomeric carboxylic acids of composition C5H10O2: a) 3 b) 2 c) 4 d)2) When dissolved in water, 1 mol of acetic anhydride forms:
a) 2 moles of ethanol
b) 2 mol of ethanol
c) 2 mol of acetic acid
d) 1 mol of methyl acetate
3) What substances does sodium acetate react with:
a) hydrochloric acid
b) Sodium hydroxide when heated
c) Carbonic acid
4) When interacting ethanol and carbon monoxide (II) under appropriate conditions, it turns out?
a) ethanal
b) propanal
c) propanoic acid
d) methyl acetate
5) What type of reactions can unsaturated carboxylic acids enter into: a) Oxidation
b) Polymerization
c) Connections
d) Esterification
6) What substances does formic acid react with:
a) Copper II chloride
b) Sodium sulfate
c) Potassium bicarbonate
d) ammonia solution of silver oxide I
7) Unlike stearic acid, oleic acid:
a) Liquid at room temperature
b) soluble in water
c) Discolors bromine water
d) Reacts with alkalis
8) What substances react with water:
a) linoleic acid
b) ethanol
c) propanal
d) propane
9) What single reagent can be used to distinguish between solutions of glycerol, propanal, and ethanoic acid:
a) bromine water
b) potassium carbonate
c) copper hydroxide II
d) nitric acid
10) In reactions with what substances with the participation of acetic acid, a hydrostrong group is split off from its molecule:
a) metals
b) alkalis
c) alcohols
d) metal carbonates
Help pliz, solve two problems!: (put 11 points 1) With which of the following substances: sodium hydroxide, bromine water, dimethyl ether -
