Question

If the number of aromatic compounds in the given set of compounds is X, and the number of non-aromatic compounds in the same set is Y, then, X+Y is: .

Answer 1

The above structure is non-aromatic despite having 6 pi-electrons as it is non-planar because of the presence of one $s{p}^3$ hybridised C atom.

The above compound is aromatic as it is cyclic, planar, the electrons are delocalised and it has 6 pi-electrons.

The above structure is also aromatic as it has 2 pi-electrons.


The above compound is non-aromatic because of the presence of one C atom which is $s{p}^3$ hybridised which makes it non-planar.


The above species is stable because both the rings are aromatic in nature.

The above structure is anti-aromatic because the lone pair of electrons on nitrogen also delocalised into the ring, making the total number of pi-electrons to be 8.

Cyclooctatetraene is expected to be anti-aromatic, but it is actually non-aromatic because the ring becomes tub shaped and hence, the planarity is lost.

Total number of aromatic compounds = X = 3

Total number of non-aromatic compounds = Y = 3

X+Y=6