Question

Which of the allotropic forms of carbon is aromatic in nature?

• A. Diamond
• B. Graphite
• C. Buckminster fullerene
• D. Coke

Hint:

Graphite has delocalized π-electrons in layers, making it aromatic in nature.

Answer 1

The Correct Option is B

Step 1: Understanding Aromaticity 
A compound is aromatic if it has: 
- A planar conjugated π-system 
- Delocalized \( 4n+2 \) π-electrons (Hückel’s rule)

Step 2: Analyzing Allotropes of Carbon 
- Diamond: 3D network, no delocalized electrons 
- Graphite: Layered structure, delocalized π-electrons
- Buckminster fullerene: Curved structure, not fully delocalized 
- Coke: Amorphous carbon, no defined conjugation 
Thus, Graphite is aromatic.

Answer 2

Carbon exists in several allotropic forms, each with distinct physical and chemical properties. The common allotropes include diamond, graphite, graphene, fullerenes, and carbon nanotubes.

Among these, graphite is aromatic in nature.

Explanation:
- In graphite, each carbon atom is bonded to three other carbon atoms in a planar hexagonal lattice.
- This arrangement forms layers of conjugated hexagonal rings, similar to benzene rings, with delocalized π-electrons above and below the plane.
- The delocalized π-electrons allow for resonance stabilization, a key characteristic of aromatic compounds.
- This aromaticity contributes to graphite's electrical conductivity and chemical stability.

Other allotropes like diamond have a tetrahedral structure with localized sigma bonds and are non-aromatic.

Therefore, the allotropic form of carbon that is aromatic is:
Graphite