Organic Chemistry Multiple Choice Questions on “Amides”.
1. When acetamide is treated with HNO2, the gas is evolved which of the following?
a) H2
b) O2
c) N2
d) CH4
Answer: c
Clarification: When acetamide is treated with HNO2, the gas is evolved in nitrogen gas.
CH3 – CO – NH2 + HNO2 → CH3COOH + N2↑ + H2O
Acetamide Acetic acid
2. On heating acetamide in presence of P2O5, which of the following is formed?
a) Ammonium acetate
b) Acetonitrile
c) NH3
d) Methylamines
Answer: b
Clarification: On heating acetamide in presence of P2O5, acetonitrile is formed.
3. Decreasing order of basicity of the given compound is which of the following?
(1) CH3CONH2 (2) CH3CH2NH2 (3) PhCH2CONH2
a) 1 > 2 > 3
b) 2 > 1 > 3
c) 3 > 2 > 1
d) 1 > 3 > 2
Answer: b
Clarification: Comparing the basicity of alkyl amines to amides. With an alkyl amine the lone pair electron is localized on the nitrogen. However, the lone pair electron on an amide are delocalized between the nitrogen and the oxygen through resonance. This makes amides much less basic compared to alkyl amines. And more the stabilization in amide less will be basic, here PhCH2CONH2 will be stabilizes by resonance.
4. By refluxing unsubstituted amide with acid, it will yield which of the following product(s)?
a) ammonia
b) carboxylic acid
c) nitrogen gas
d) ammonia and carboxylic acid
Answer: d
Clarification: By refluxing unsubstituted amide with acid, it will yield and ammonia and carboxylic acid.
5. Which one of the following reducing agents is likely to be the most effective in bringing about the following change?
R−CONH2 → RCH2NH2
a) H2−Ni
b) NaBH4
c) LiAlH4
d) Na-alcohol
