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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3g1097

Which of the following are aromatic?

Apyridine
Bcyclopenta-2,4-dien-1-ylium (cyclopentadienyl cation)
Cpyrrole
Dfuran

Answer: A, C, D

Pyrrole and furan are planar with 6

π

electrons (4 from two C=C bonds and 2 from the heteroatom lone pair). Pyridine has 6

π

electrons (three C=C bonds) in a planar ring. The cyclopentadienyl cation has 4

π

electrons and is antiaromatic.

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