Table of Contents
How do you synthesis benzene?
Benzene is prepared from ethyne by the process of cyclic polymerization. In this process, Ethyne is passed through a red-hot iron tube at 873 K. The ethyne molecule then undergoes cyclic polymerization to form benzene.
What type of reaction are shown by benzene?
Electrophilic Substitution reaction
Electrophilic Substitution reaction is a characteristic of an aromatic compound. Hence option (D) is correct.
What are the reagents used in the synthesis of benzene?
Reactivity of benzene
| Reaction | Reagent | Product |
|---|---|---|
| Halogenation | X2 (X=Cl, Br) | ArCl, ArBr |
| Nitration | HNO3 | ArNO2 |
| Sulfonation | H2SO4 or H2S2O7 | ArSO3H |
| Friedel-Crafts alkylation | RX, ArCH2X | Ar-R, Ar-CH2Ar |
What are the main reactions of benzene?
Substitution Reactions of Benzene and Other Aromatic Compounds
| Reaction Type | Typical Equation | |
|---|---|---|
| Halogenation: | C6H6 | + Cl2 & heat FeCl3 catalyst |
| Nitration: | C6H6 | + HNO3 & heat H2SO4 catalyst |
| Sulfonation: | C6H6 | + H2SO4 + SO3 & heat |
| Alkylation: Friedel-Crafts | C6H6 | + R-Cl & heat AlCl3 catalyst |
How is benzene prepared in the laboratory give its chemical reaction?
In the laboratory, benzoic acid or sodium benzoate is heated with soda lime (NaOH+CaO) to obtain benzene.
How do you synthesize phenol from benzene?
In this method, benzene sulfonic acid is reacted with aqueous sodium hydroxide. The resulting salt is mixed with solid sodium hydroxide and reacted at a high temperature. The product of this reaction is sodium phenoxide, which is acidified with aqueous acid to make phenol.
What happens when benzene reacts with fuming sulphuric acid?
With fuming H2SO4 or oleum (conc. H2SO4+SO3) react with benzene at high temperature then it forms m-benzene disulphonic acid. The attacking species for this reaction is SO3.
Which of the following reactions is not shown by benzene?
So, Addition reaction is not shown by benzene.
Which catalyst is used during halogenation of benzene?
The halogenation of benzene The catalyst is either aluminum chloride (or aluminum bromide if you are reacting benzene with bromine) or iron. Strictly speaking iron is not a catalyst, because it gets permanently changed during the reaction.
What is substitution reaction explain any two substitution reactions of benzene?
What are the two methods of preparation of benzene?
Answer. 1- By the decarboxylation of sodium benzoate. 2- By heating phenol with zinc. 3- By the polymerization of ethyne.
Which of the following is laboratory preparation of benzene?
By the decarboxylation of sodium benzoate This method is used in the laboratory to obtain benzene. Sodium benzoate is heated with soda-lime and when it gets decarboxylated (removal of carbon dioxide) benzene is obtained.
Which is the correct method to synthesis phenol?
How do you convert benzene to benzoic acid?
Convert benzene to methyl benzene by reacting it with CH3Cl and anhydrous AlCl3. Oxidize methyl benzene with a powerful oxidizing agent like alkaline KMnO4 we will get benzoic acid.
What happens when benzene is heated with H2SO4 at 250?
Benzene on heating with conc. H2SO4 gives benzene sulphonic acid which when heated with superheated steam under pressure gives benzene.
Why fuming H2SO4 is used in sulphonation?
Sulfonation is a reversible reaction that produces benzenesulfonic acid by adding sulfur trioxide and fuming sulfuric acid. The reaction is reversed by adding hot aqueous acid to benzenesulfonic acid to produce benzene.
What type of reaction is nitration of benzene?
Nitration of benzene by nitric acid and sulphuric acid is an Electrophilic substitution reaction. Nitration is the class of chemical process that introduces the nitro group into an organic chemical compound.
What catalyst is needed for nitration of benzene?
concentrated sulfuric acid
The electrophilic substitution reaction between benzene and nitric acid. The concentrated sulfuric acid is acting as a catalyst.
What reactions does benzene undergo?
Benzene has delocalized electrons .Hence,it is electron rich .
Why is benzene resistant to addition reactions?
– electrophillic substitution (nitration, sulfonation, halogenation etc) relatively easily (low energy) and very common – Nucleophilic substitution of VERY electron deficient aromatic compounds less common but under the right conditions very favourable – addition reactions like hydrogenation or free radical chlorination uncommon and high energy
Why is methyl benzene more reactive than benzene?
The sulphonation of methylbenzene Methylbenzene is more reactive than benzene because of the tendency of the methyl group to “push” electrons towards the ring. Exactly how this increases the rate of reaction is beyond UK A level – it is rather more complicated than just an increase in the electron density of the ring.
Why does benzene react by substitution?
Benzene is a planar molecule having delocalized electrons above and below the plane of ring. Hence, it is electron-rich. As a result, it is highly attractive to electron deficient species i.e., electrophiles. Therefore, it undergoes electrophilic substitution reactions easily. Nucleophiles are electron-rich. Hence, they are repelled by benzene.