Find the 12th Class Fsc Chemistry Online Preparation chapter 9 ( Aromatic Hydrocarbons)

Question # 1

Write down nitration and sulphonation of benzene?

Ans 1: The introduction of NO₂group in benzene ring is called Nitration,.The nitration of benzene takes place when it is heated with a 1:1 mixture of conc.HNO₃and conc.Sulphuric at 50-55 degree acid reacts with nitrir acid to generate nitronium ion.

Question # 2

Define resonance energy?What is the resonance energy of benzene?

Ans 1: Benzene is more stable than the hypothetical 1,3,5-cyclohexatriene by 150.5 kj/mole.This difference between amount of heat is actually released and that calculated on the basis of the Kekule structure is called Resonance Energy Benzene shows the phenomenon of resonance which makes it more stable than others.In benzene electrons are delocalized making it a very stable molecule.The resonance energy of benzene is 150.5 kj/mole

Question # 3

Predict major product of bromination of nitrobenzene.

Ans 1: m-bromonitrobenzene is the major product of bromination of nitrobenzene because nitro group on benzene is meta directing .

Question # 4

What are the major product when chlorine reacts with Toluene in the presence of sunlight?

Ans 1: When alkyl benzene are treated with chlorine or bromine in the presence of sunlight ,only the alkyl groups are submitted.

Question # 5

How benzene is converted into malic acid by catalytic oxidation?

Ans 1: Benzene ring is determine when it is strongly heated with air in the presence of V₂O₅as a catalyst and maleic acid is obtained.

Question # 6

What is meant by the terms:i) Aromatic ii) Oxidation

Ans 1: Aromatic:The term aromatic was derived from the Greek word aroma meaning fragrant and was used in organic chemistry for s special class of compounds.These compounds have low hydrogen to carbon ratio in their molecular formula and have a characteristic odour. These often produced by benzene or derivatives of benzene.
Ans 2: Oxidation:The addition of oxygen,removal of hydrogen or electrons is called oxidation.Oxidation process is carried out by some oxidizing agent like KMnO₄,K₂Cr₂O₇or V₂O₅etc.which can provide oxygen to a compound.

Question # 7

Why benzene is less reactive than alkenes although it has three pi bonds in it?

Ans 1: Benzene is extraordinary stable molecule,This stability is due to the extensive delocalization of pi electron.The unhybridized orbital partially overlap to form a continue sheath of electron cloud,enveloping above and below the six carbon carbon sigma bonds of the ring,

Question # 8

What is meant by directing group?

Ans 1: The groups which withdraw the electrons of the benzene ring towards themselves and reduce the availability to the electrophiles are called meta directing groups.The result is the decrease chemical reactivity of benzene,In their presence incoming electrophiles will prefer to attack on meta position nrather than orho and para position.

Question # 9

What is Wurtz -Fritting reaction?

Ans 1: The Wurtz reaction for the synthesis of alkanes was extended by Fitting in 1864 to the synthesis of alyl aromatic hydrocarbons.

Question # 10

What is meant by directive influence of substituent?

Ans 1: When an electrophile substitution reaction take place on the benzene ring,we get only one monosubstituted benzene all the six position in the ring are equivalent .However introduction of second group into the ring may give three isomeric distributed products ,ortho,meta and para.

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12th Class Fsc Chemistry Online Preparation chapter 9 ( Aromatic Hydrocarbons)

Online Short Questions For Chapter 9 "12th Class Chemistry Chapter 9 Short Questions Preparation "

Chemistry - 12th Class Chemistry Chapter 9 Short Questions Preparation

Write down nitration and sulphonation of benzene?

Define resonance energy?What is the resonance energy of benzene?

Predict major product of bromination of nitrobenzene.

What are the major product when chlorine reacts with Toluene in the presence of sunlight?

How benzene is converted into malic acid by catalytic oxidation?

What is meant by the terms:i) Aromatic ii) Oxidation

Why benzene is less reactive than alkenes although it has three pi bonds in it?

What is meant by directing group?

What is Wurtz -Fritting reaction?

What is meant by directive influence of substituent?

Prepare Complete Set Wise Questions For Chapter 9 "12th Class Chemistry Chapter 9 Short Questions Preparation "

Set 1

Set 2

12th Class Chemistry Chapter 9 Short Questions Preparation - Set 1

Write down nitration and sulphonation of benzene?

Define resonance energy?What is the resonance energy of benzene?

Predict major product of bromination of nitrobenzene.

What are the major product when chlorine reacts with Toluene in the presence of sunlight?

How benzene is converted into malic acid by catalytic oxidation?

What is meant by the terms:i) Aromatic ii) Oxidation

Why benzene is less reactive than alkenes although it has three pi bonds in it?

What is meant by directing group?

What is Wurtz -Fritting reaction?

What is meant by directive influence of substituent?

12th Class Chemistry Chapter 9 Short Questions Preparation - Set 2

What is the general pattern of reactivity of benzene towards electrophone?

What is Wurtz -Fritting reaction?

Justify that Ethene is more reactive than C6H6.

What is meant by directing group?

What happens when Acidified KMnO4is added to Methyl Benzene and Ethylbenzene?

Define two reaction which confirm presence of three double bonds in benzene ring.

What are aromatic hydrocarbons?Give two example.

Define two reaction which show that Benzene is an unsaturated hydrocarbons?

Predict major product of bromination of nitrobenzene.

What is resonance?

12th Class Chemistry Chapter 9 Preparation

Share your comments & questions here

Justify that Ethene is more reactive than C₆H_6.

What happens when Acidified KMnO₄is added to Methyl Benzene and Ethylbenzene?