Organic Chemistry Question Bank on “Benzene diazonium chloride – 2”.
1. Replacement of diazo group by other groups is helpful in preparing those substituted aromatic compounds which cannot be prepared which type of reaction?
a) Direct elimination
b) Addition reaction
c) Direct substitution
d) Replacement reaction
Answer: c
Clarification: Replacement of diazo group by other groups is helpful in preparing those substituted aromatic compounds which cannot be prepared by direct substitution.
2. What happens when benzene diazonium chloride is treated with potassium cyanide in presence of Cu powder?
a) Benzophenone
b) Methyl isocyanide
c) Acetonitrile
d) Benzonitrile
Answer: d
Clarification: By treating diazonium salts with cuprous cyanide or KCN and copper powder it forms aryl nitrile. Illustrative is the preparation of benzonitrile using the reagent cuprous cyanide: C6H5N+2 + CuCN → C6H5CN + Cu+ + N2.
3. By treating diazonium salts with cuprous cyanide or KCN and copper powder it forms which of the following compound?
a) Citric acid
b) Benzoic acid
c) Aryl nitrile
d) Oxalic acid
Answer: c
Clarification: By treating diazonium salts with cuprous cyanide or KCN and copper powder it forms aryl nitrile. The cyano group usually cannot be introduced by nucleophilic substitution of haloarenes, but such compounds can be easily prepared from diazonium salts.
4. Benzene diazonium chloride forms orange red dye with which of the following compound?
a) Nitrophenol
b) Benzophenol
c) Resorcinol
d) Methanol
Answer: c
Clarification: Benzene diazonium chloride forms orange red dye with resorcinol, Reaction of benzene diazonium chloride with resocinol in basic medium is a coupling reaction,in which p-hydroxyazobenzene is obtained .Which is nothing but orange dye.
5. Which of the following is compound A for following sequence of reaction gave benzoic acid benzoic acid?
a) Nitrobenzene
b) Aniline
c) Benzaldehyde
d) Amides
Answer: b
Clarification: In the following sequence reaction between aniline and NaNO2/HCl will form diazonium salt and with KCN it will form cyanide and at last carboxylic acid will be formed.
6. In the series of reaction, what are X and Y are respectively?
a) C6H5−N=N−C6H5, C6H5N+2Cl–
b) C6H5N+2Cl–, C6H5−N=N−C6H5
c) C6H5N+2Cl–, C6H5NO2
d) C6H5NO2, C6H6
Answer: c
Clarification: In the following sequence reaction between aniline and NaNO2/HCl will form diazonium salt and with HNO2 nitrobenzene will be formed.
7. Aniline in a set of reactions yielded a product D. The structure of product D would be
a) C6H5CH2NH2
b) C6H5NHCH2CH3
c) C6H5NHOH
d) C6H5CH2OH
Answer: d
Clarification: First of all, diazonium will be formed and then it will show Sandmeyer reaction with CuCN and then reduction of cyanide and oxidation to benzyl alcohol.
