Discussion Forum

1)

Among P, Q, R, S, the aromatic compound (s) is/are 

Answer:

Option A,B,C,D

Explanation:

 Plan A specially said to have aromatic character if 

(a) ring is planar

(b)  there is complete delocalisation of $\pi$  electrons

 (c)    Huckel rule i.e, (4n+2)  rule is followed

 where n is the number of rings (4n+2)=$\pi$ electron delocalised.

                  n      (4n+2)         $\pi$ electrons

P     -       0         2                   2

Q     -       1         6                   6( Including  lone pair)

R     -         1        6                  6( including lone pair on N)

S     -        1         6                   6

In all cases there is complete delocalisation of $\pi$ -electrons