Problems related to organic matter and bromine reactions

1.Methane and bromine occur as a free radical substitution reaction: so the bromine used must be pure bromine, either gaseous or liquid, and cannot be an aqueous solution. It's just that pure bromine is usually liquid, and the contact surface of the gaseous state is easy to react;

2.Addition reaction of ethylene and bromine: the bromine used is gaseous, liquid and aqueous solution, and the carbon tetrachloride solution of bromine is generally used to increase the dissolved amount of bromine;

3.Substitution reaction of benzene (with ferric chloride as catalyst) and bromine: the bromine used is pure bromine, which can be in gaseous or liquid form, and cannot be an aqueous solution. Without a catalyst, the reaction is very slow, very slow. Note that when iron is used as a catalyst, it is not heated, and the reaction should be exothermic reaction;

4.Ethanol can have substitution reactions with HBR and PBR3; CH3COOH can react with Pcl3, Pcl5, SOCL2 and other hydroxyl sites, such as CH3COOH+SOCl2===CH3COCL

CH3COOH can undergo A-- halogenation reaction with halogen under the condition of P as catalyst, for example: CH3COOH + CL2====ClCH2COOH + HCl

5.Benzene and sodium carbonate are not miscible because the structures are not similar.

1.Liquid. 2.Aqueous solution, preferably carbon tetrachloride solution of bromine.

3.Liquid bromine, without catalysts, reacts very little and slowly.

4.Ethanol and bromine can undergo substitution reactions, but bromine may oxidize ethanol.

5.Not miscible.

Substitution reaction of methane and bromine Bromine is in a gaseous state.

Addition reaction of ethylene and bromine Substitution reaction of liquid aqueous solution both are right benzene (with ferric chloride as catalyst) and bromine: liquid state, no reaction without catalyst.

Ethanol, acetic acid, and bromine can undergo substitution reactions.

1.Gaseous because methane is gaseous.

2.Liquid, bromine water is used.

3.Liquid, no catalyst does not react.

4.We didn't teach either, sorry.

Benzene should not be miscible with sodium carbonate.

1. Gaseous. 2.Carbon tetrachloride solution.

3.Liquid bromine. 4.Alcohol substitution is to be replaced with PBR3

Acetic acid can react with bromine to form 1-bromo-acetic acid.

To replace the hydroxyl group in the carboxyl group, pbr3 is used

5.Not miscible.

1.Alkanes and halogen gases can be replaced.

2.Both gaseous and aqueous solutions are fine.

3.Bromine should be liquid bromine, and there should be no catalyst to react, the rate is just fast or slow.

4.I don't think so.

5.Benzene is insoluble in water, does not react with Na2CO3, and should not be dissolved with sodium carbonate solution.

In secondary school chemistry, the functional groups that can react with bromine water are:

1. Carbon-carbon double and triple bonds.

The addition reaction occurs H2=CH2+BR2=CH2BR-CH2BR

2. Aldehyde group.

The redox reaction occurs H2O+BR2+CH3COH CH3COOH+2HBR

Organic chemical reactions mainly occur on functional groups, which play a decisive role in the properties of organic matter, -X, -OH, -CHO, -COOH, -NO2, -SO3H, -NH2, RCO-, these functional groups determine the chemical properties of halogenated hydrocarbons, alcohols or phenols, aldehydes, carboxylic acids, nitro compounds or nitrites, sulfonic acid organic compounds, amines, and amides in organic matter.

Chemical Properties:

Functional groups play a decisive role in the properties of organic matter, -X, -OH, -CHO, -COOH, -NO2, -SO3H, -NH2, RCO-, these functional groups determine the chemical properties of halogenated hydrocarbons, alcohols or phenols, aldehydes, carboxylic acids, nitro compounds or nitrites, sulfonic acid organic compounds, amines, and amides in organic matter.

Therefore, learning the nature of organic matter is actually learning the nature of functional groups, and organic matter containing any functional group should have the chemical properties of this functional group, and organic matter that does not contain such functional groups does not have the chemical properties of this functional group, which is a point that should be recognized in the study of organic chemistry.

The above content reference: Encyclopedia - Functional Group.

In secondary school chemistry, the functional groups that can react with bromine water are:

1. Carbon-carbon double and triple bonds.

The addition reaction occurs H2=CH2+BR2=CH2BR-CH2BR2, aldehyde group.

The redox reaction occurs H2O+BR2+CH3COH CH3COOH+2HBR

3. Phenol pickpocket.

A substitution reaction occurs.

Brho—benzene ring—CH3 + 2BR2 HO—benzene ring—CH3 (white precipitate) +2HBR

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The chemical equation of the reaction between bromine and water is: BR2+H2O=HBR+HBRO, which is a reversible reaction.

Bromine is a volatile red-black liquid, belonging to the halogen group of combustible elements, soluble in water, with stronger oxidation than rent, bromine vapor is toxic and corrosive.

Generally used for addition reactions, bromine water is used; For substitution reactions, liquid bromine is used, because the side reactions caused by pure substances are less than those caused by bromine water.

Liquid bromine is suitable for substitution reactions with hydrocarbons.

Both liquid bromine and bromine water can be used in addition reactions.

and phenol substitution is concentrated bromine water.

The reaction with benzene is liquid bromine.

Remember the last two.

Key liquid bromine is generally used for the removal of impurities of unsaturated hydrocarbons in the main topic.

If you want a high concentration, you must use liquid bromine, and if the reaction can be carried out at a low concentration, you can use bromine water, which has a very low concentration of bromine, almost less than 1mol l

Therefore, some reactions require low concentrations to have liquid bromine.

Liquid bromine is pure bromine.

Bromine water can be used in organic chemistry for substitution reactions, such as excess concentrated bromine water reacts with phenol to form tribromophenol [white precipitate] addition reactions, such as olefins and alkynes can fade bromine water.

In organic chemistry, liquid bromine can be used for substitution reactions, such as benzene and liquid bromine under the condition of iron as catalyst to produce bromobenzene [soluble in benzene] addition reactions, such as addition with olefins and alkynes.

There is also an important law in chemistry to remember: similarity and dissolution. That is, substances with the same spatial structure and molecular polarity can dissolve with each other.

Bromine water: A mixture of bromine elements and water.

In high school chemistry, ethylene undergoes an addition reaction with bromine to produce 1,2-dibromoethane, which requires only bromine water. Liquid bromine is required for the substitution reaction of bromine and benzene under the condition that Febr3 is used as a catalyst.

(1) The substitution reaction between alkanes and bromine vapor occurs under light conditions (2) The addition reaction of alkenes or alkynes with bromine water or carbon tetrachloride solution of bromine (3) The substitution of phenol solution with excess concentrated bromine water on the benzene ring generates a white precipitate of tribromophenol (4) Benzene and liquid bromine are substituted when iron is used as a catalyst to form bromobenzene (5) Alkanes Hydrocarbons and esters can be extracted from bromine water (6) Other non-reactive such as carboxylic acids are miscible with bromine water and I have summarized my years of teaching.

Organic compounds reacting with bromine water: alkynes, olefins.

The structural formula of alkenes and alkynes contains double bonds, which can undergo addition reaction with bromine water.

For example: ch3ch=ch2+br2 ==ch3chbr-ch2br.

Organic compounds reacting with liquid bromine: benzene, aromatic hydrocarbons.

BR can undergo substitution reaction with benzene and aromatic hydrocarbons to replace H on organic matter.

For example: phenol + 3BR2 (refers to 3 liquid bromine) = = 3HBR + phenol bromine (precipitate).

Bromine water: A mixture of elemental bromine and water. Bromine is slightly soluble in water.

Bromine over 80 will react with water to form hydrobromic acid and hypobromic acid, but a small amount of bromine will still be dissolved in the water, so the bromine water has an orange-yellow color. The newly produced bromine water can be regarded as an aqueous solution of bromine, which is undergoing a chemical reaction related to bromine, but over a long period of time, the bromine molecules in the bromine water will also decompose, and the bromine water will gradually fade. For a long time, bromine water contained only hydrobromic acid.

Hypobromoic acid decomposes into hydrobromic acid and oxygen under light.

So, what are the learning methods?

1. Preview. Preview is a very important learning method, through preview, you can be familiar with the content and structure of the article, in the process of preview, you can mark the place you don't understand, so that when you go to class, you can take questions, let yourself listen to the class in a targeted manner, and then improve the interest and efficiency of learning.

2. Take notes during lectures.

Listening to lectures is an important way for people to receive information. In the process of listening to the lecture, people can learn most of the content, so it is very important to grasp the lecture well. Be sure to concentrate, listen to the teacher, take notes, participate in class activities, and actively ask questions.

3. Do your homework carefully.

After the lesson, the teacher will give the students homework. The purpose of the assignment is to further consolidate what has been learned in class. So, be sure to take your homework seriously.

4. Review and summary.

After learning, you must review and summarize, through review and summary, you can make the content you learn become your own knowledge, and in the review and summary, you can find new problems and further deepen your understanding of the knowledge points.

5. Maintain self-confidence.

Self-confidence can bring great motivation to people, and only with self-confidence can we make every day more energetic and better remember what we have learned.

Only benzene is liquid bromine and heated, the others are bromine water, especially c=c

Comparison of liquid bromine, bromine water, acidic potassium permanganate solution with various hydrocarbon reactions.

Aldehydes can be oxidized by bromine water to form acetic acid.

Aldehydes can react with bromine water.

Alkynes and hydrocarbons seem to be able to react with bromine water, but I forgot exactly.

Reaction of unsaturated hydrocarbons such as olefins, alkynes, and diolefins.

It reacts with phenol and aniline to form a white precipitate.

It reacts with aldehydes and other substances with aldehyde groups.

4.Substitution reaction with ketones with alpha hydrogen, ring-opening addition with cyclopropane and its derivatives For the oxidation reaction of ergonol, bromine water can oxidize ergonol to aldehydes and ketones relatively slowly, and further undergo the two types of reactions mentioned above.

Cyclopropane and its derivatives can undergo an open-ring addition reaction with bromine water, which can be combined with potassium permanganate to test the ternary carbon ring, because cyclopropyl cannot react with potassium permanganate at room temperature.

Reaction with alkaline solution (such as NaOH solution, Na2CO3 solution, etc.) Reaction with strong inorganic reducing agents (such as H2S, SO2, Ki and Feso4, etc.) Mixed with benzene, toluene, carbon tetrachloride and other organic solutions, the bromine water fades due to extraction, and the organic solvent dissolves the bromine orange (or brownish-red).

Olefins and alkynes undergo an addition reaction with bromine, and alkanes and liquid bromine or bromine vapor undergo a substitution reaction under light.

Organic compounds containing double or triple bonds (except benzene) can be discolored by addition reaction with bromine water.

Phenol. It can replace with bromine water to form a white precipitate.

Organics containing double or triple bonds (except benzene) and acidic potassium permanganate.

In addition, benzene homologues can also undergo redox reactions with acidic potassium permanganate.

1.Additions in hydrocarbons: contain carbon-carbon double bonds; Carbon-carbon triple bond;

2.Substitution on benzene ring in hydrocarbon derivatives: phenol benzene ring ortho, para-hydrogen atom contained; amine-benzene ring ortho, para-hydrogen atom;

3.Oxidation of derivatives of hydrocarbons: contains aldehyde groups.

Bromine water: A mixture of bromine elements and water.

Summary. The substitution of hydrogen on saturated carbon is a reaction of free radicals, which cannot exist in water. In other words, the substitution reaction is not possible in the presence of water. [Bromine water cannot be used, regardless of concentration].

Why methane does not react with bromine water, but replaces the reaction with bromine.

The substitution of hydrogen on saturated carbon is a reaction of free radicals, which cannot exist in water. In other words, the substitution reaction is not possible in the presence of water. [Bromine water cannot be used, regardless of concentration].

The concentration of bromine in bromine water is low (bromine is not soluble in water), while the concentration of bromine elemental can be considered to be 100%, so it can react with methane.

The principle of substitution reaction between alkanes and halogens determines that they can only react with pure halogens, and it is difficult to carry out the reaction with water.