Organic Chemistry Multiple Choice Questions on “Preparation of Amines – 1”.
1. The amine formed from an amide by means of bromine and alkali has how many number of carbon atoms?
a) Same number of C atoms as that of amide
b) One less C atom than that of amide
c) One more C atom than that of amide
d) Two more C atoms than that of amide
Answer: b
Clarification: The amine formed from an amide by means of bromine and alkali has one less C atom than that of amide.
2. The compound X is which of the following?
a) CH3CONH2
b) CH3CH2NH2
c) C2H6
d) CH3NHCH3
Answer: b
Clarification: Reduction of nitriles leads to formation of primary amine.
3. Ethylamine can be prepared by the action of bromine and caustic potash on which compound?
a) Acetamide
b) Propionamide
c) Formamide
d) Methyl cyanide
Answer: b
Clarification: Ethylamine can be prepared by the action of bromine and caustic potash on propioamide.
CH3 – CH2 – CO – NH2 + Br2 + 4KOH → CH3CH2NH2 + K2CO3 + 2KBr + 2H2O
propioamide
4. Reduction of nitroalkanes yields which compound?
a) Acid
b) Alcohol
c) Amine
d) Diazo compounds
Answer: b
Clarification: Reduction of nitroalkanes yields amines, as shown in below reaction.
5. What is the name of the reaction when acetamide changes into methylamine?
a) Hofmann bromamide reaction
b) Hofmann reaction
c) Friedel-Craft’s reaction
d) Hinsberg reaction
Answer: a
Clarification: When an amide is treated with bromine in an aqueous or ethanolic solution of sodium hydroxide, degradation of amide takes place leading to the formation of primary amine. This reaction involving degradation of amide and is popularly known as Hoffmann bromamide degradation reaction.
6. When methyl iodide is heated with ammonia, what is the product obtained?
a) Methylamine
b) Dimethylamine
c) Trimethylamine
d) A mixture of Methylamine, Dimethylamine & Trimethylamine
Answer: d
Clarification: When methyl iodide is heated with ammonia, the product obtained is mixture of methylamine, dimethylamine, trimethylamine.
7. The Hinsberg’s method is used for which of the following?
a) Preparation of primary amines
b) Preparation of secondary amines
c) Preparation of tertiary amines
d) Separation of amine mixtures
Answer: d
Clarification: The Hinsberg reaction is a test for the detection of primary, secondary and tertiary amines. In this test, the amine is shaken well with Hinsberg reagent in the presence of aqueous alkali (either KOH or NaOH). A reagent containing an aqueous sodium hydroxide solution and benzenesulfonyl chloride is added to a substrate.
8. Which one of the following compound gives a secondary amine on reduction?
a) Nitromethane
b) Nitrobenzene
c) Methyl isocyanide
d) Methyl cyanide
Answer: c
Clarification: Methyl isocyanide gives a secondary amine on reduction.
