Question

Which one of the following is correct statement of fullerenes? (a) Fullerenes are made by heating of graphite in an electric arc in the presence of Hydrogen. (b) Fullerenes are the only impure form of carbon due to presence of dangling bonds. (c) It contains twenty six-membered rings and twelve five membered rings. (d) Both (a) and (b).

Short answer

(c) It contains twenty six-membered rings and twelve five-membered rings.

Step-by-step solution

Understand What Fullerenes Are

Fullerenes are molecules composed entirely of carbon, taking the form of a hollow sphere, ellipsoid, or tube. They consist of carbon atoms connected in a mesh of pentagons and hexagons, with the most famous fullerene being the buckminsterfullerene (60), resembling a soccer ball with 20 hexagons and 12 pentagons.

Evaluate Statement (a)

Statement (a) suggests that fullerenes are made by heating graphite in an electric arc in the presence of hydrogen, which is incorrect. Fullerenes are typically synthesized by vaporizing graphite with an electric arc but in an inert gas environment like helium or argon, not hydrogen.

Evaluate Statement (b)

Statement (b) claims that fullerenes are the only impure form of carbon because of dangling bonds. This is incorrect because fullerenes have all carbon atoms perfectly bonded in a closed structure with no dangling bonds, making them pure forms of carbon like graphite and diamond.

Evaluate Statement (c)

Statement (c) correctly describes the structure of buckminsterfullerene, mentioning that it contains twenty hexagons and twelve pentagons. This precise configuration is what gives buckminsterfullerene its stability and unique properties.

Analyze Statement (d)

Statement (d) is claiming multiple statements, (a) and (b), which we have already evaluated and found incorrect. Thus, (d) is not the correct answer.

Key concepts

Carbon Structures

Carbon, as a versatile element, forms various types of structures due to its ability to create four bonds. Two key structures are graphite and diamond, based on the arrangement and bonding of carbon atoms. Fullerenes, though less commonly discussed, are fascinating additions to the family of carbon structures.
Unequivocally, all carbon structures, including fullerenes, are pure forms of carbon. This means that the carbon atoms in fullerenes do not have dangling bonds as highlighted in misconceptions like Statement (b) from the original exercise.
In essence, carbon can be organized into different geometrical patterns, making the study of carbon structures an exciting chapter in materials science. Understanding these formations can help in developing new materials with unique properties.

Buckminsterfullerene

Buckminsterfullerene, often denoted as \(C_{60}\), is one of the most renowned fullerenes and is known for its distinct "soccer ball" shape. Invented in 1985, this molecule has become iconic in the world of chemistry due to its spherical configuration. This structure features 20 hexagons and 12 pentagons, ensuring no two pentagons share a side.What makes buckminsterfullerene special is its stability, attributed to its closed structure and the even distribution of stress across its surface. It has potential applications in areas such as medicine, electronics, and nanotechnology due to its unique properties.Whether or not you're familiar with buckminsterfullerene, its mesmerizing architecture makes it a captivating topic for those exploring carbon-based materials.

Allotropes of Carbon

Allotropes are different structural forms of an element, and carbon has several notable allotropes. The most recognized ones include:

• Diamond: A crystal structure where each carbon is bonded to four others in a strong, 3D network.
• Graphite: A layered structure with carbon atoms arranged in hexagonal sheets, allowing layers to slide over one another.
• Fullerenes: Molecules arranged in closed cages with pentagons and hexagons, such as buckminsterfullerene.
• Graphene: A single layer of graphite, prized for its strength and electrical conductivity.

These allotropes exhibit diverse properties, from hardness in diamonds to conductivity in graphene. This diversity makes carbon an incredibly important element in material science, capable of applications ranging from industrial to technological innovations.