Question

Which of the following allotropic form of carbon used in making crucibles-

• A. Diamond
• B. Graphite
• C. Fullerene
• D. Coke

Answer 1

The correct option is B

Graphite

Allotropy: Allotropy is the presence of a chemical element in two or more forms, each of which differs in the arrangement of atoms.

Examples:

1. The main allotropes of carbon are Diamond, Graphite, and Fullerenes

2. Phosphorous has three main allotropes, they are white phosphorous, red phosphorous and black phosphorous

Explanation for correct option:

B. Graphite is chemically most stable and inert to the majority of elements.

Graphite is used to build crucibles because it is chemically resistant, has a high melting point, and is an excellent heat conductor.

Explanation for incorrect options:

A. Diamond is one of the hardest substance and also its very costly. Hence making crucibles using diamonds, is undesired.

C. Fullerenes generally have much lower melting points than working conditions of crucibles

D. Coke is liquid carbon and is used in steel production. Crucibles cannot be made from it.

Hence, option (B) is the correct option.