2025 · Q105
Which one of the following statements is not correct for benzene?
General KnowledgeChemistry
- AEach carbon atom forms sigma bonds with two other carbon atoms with a bond angle of 120°.
- BDelocalized electrons create a symmetrical ‘cloud’ of electrons above and below the plane.
- CThe length of C-C bonds is intermediate between single and double bonds.
- DIt has six isomers.
Explanation
In benzene (C6H6) each carbon is sp2-hybridised, forming sigma bonds with 120° bond angles; the delocalised pi electrons form symmetrical electron clouds above and below the ring plane; and all C–C bonds are equal in length (139 pm), intermediate between single and double bonds. Benzene itself, however, has no structural isomers — it is a single unique hexagonal ring (only its derivatives show isomerism). 'It has six isomers' is therefore the statement that is not correct, confirmed against published solutions of this paper.