Question 1

In the reaction series:  { C }_{ 6 }{ H }_{ 5 }Cl\xrightarrow [Cu _{ 2 }O,\: 200^oC ]{NH_3} X; X\xrightarrow [ { 0-5 }^{ 0 }C ]{ { HNO }_{ 2 } } Z; X+Z\rightarrow A , the number of  \sigma   and  \pi   bonds in  A  are:

Accepted Answer

Nucleophilic substitution of chloro-benzene with ammonia gives aniline. { C }_{ 6 }{ H }_{ 5 }Cl\xrightarrow [ { Cu }_{ 2 }O,\: { 200 }^{ 0 }C ]{ { NH }_{ 3 } } \underset {X} {C_6H_5NH_2} +HCl  Diazotization of aniline gives benzene diazonium chloride.  \underset {X} {C_6H_5NH_2} \xrightarrow [ { 0-5 }^{ 0 }C ]{ { HNO }_{ 2 } } \underset {Z} {C_6H_5N_2Cl} Azo coupling of aniline with benzenediazonium chloride gives p-aminoazobenzene.  \underset {X} {C_6H_5NH_2}+ \underset {Z} {C_6H_5N_2Cl}\rightarrow \underset {A} {C_6H_5-N=N-C_6H_4-NH_2} The number of   \sigma   and  \pi   bonds in  C_6H_5-N=N-C_6H_4-NH_2  are  27 \sigma   and  7 \pi  .Hence, the correct option is C.

Question 2

How many structures of F are possible?

Accepted Answer

3  isomers of compound F are possible. They are shown above. Protonation in acidic conditions of the hydroxyl group of secondary alcohols converts the hydroxyl group into a leaving group, which departs as water. The carbocation intermediate can rearrange and it will then be deprotonated in a  E_1  elimination mechanism. This is the reverse of acid-catalyzed hydration of alkenes.Hence, the correct option is  D

Question 3

Select the correct option regarding compound D formed in the reaction.

Accepted Answer

Option C is correct.

Alcohols, Phenols And Ethers