1

### AIPMT 2009

Nitrobenzene can be prepared from benzene by using a mixture of conc. HNO3 and conc. H2SO4. In the mixture, nitric acid acts as a/an
A
acid
B
base
C
catalyst
D
reducing agent

## Explanation

Nitric acid acts as a base by accepting a proton.
2

### AIPMT 2008

In a reaction of aniline a coloured product C was obtained.

The structure of C would be
A
B
C
D

## Explanation

3

### AIPMT 2007

Which one of the following on reduction with lithium aluminium hydride yields a secondary amine?
A
Methyl isocyanide
B
Acetamide
C
Methyl cyanide
D
Nitroethane

## Explanation

Reduction of alkyl isocyanides in presence of LiAlH4 yields secondary amines containing methyl as one of the alkyl group.

4

### AIPMT 2006

Which of the following is more basic than aniline?
A
Benzylamine
B
Diphenylamine
C
Triphenylamine
D
$p$-Nitroaniline

## Explanation

Benzylamine is more basic than aniline. The reason is that in aniline, the lone pair of nitrogen is conjugated with benzene ring so it is not available readily for others. On the other hand in Benzylamine, nitrogen is not directly attached with ring so lone pairs are not conjugated with ring.