Question

Which of the following is the purest form of carbon?
(A) Charcoal
(B) Coal
(C) Diamond
(D) Graphite

Answer 1

Hint: We know that valency of carbon is 4. Carbon has a tendency to form networks of covalent bonds. Carbon has many allotropes. Some compounds have only carbon atoms in their structure.

Complete step by step solution:
> Carbon is the only atom in the periodic table which has a high combining capacity to form compounds and molecules with other atoms and elements.
> Elements which contain only carbon atoms in their structure. These are called the pure forms of carbon.
> Elements which are pure forms of carbon are called allotropes. They differ by the geometrical arrangement of the carbon atoms in their structures.
> Graphite and Diamond are the main allotropes of carbon.
> Diamond is the purest form of carbon or diamond is 100% carbon. It is made from graphite in the presence of catalysts such as iron, cobalt, chromium, or manganese. It is considered to be the purest form of carbon, because the composition of the diamond is homogeneous. Diamond is a form of carbon in which each carbon atom is covalently bonded to four other carbon atoms. And other forms of carbon have some impurities.
> Nitrogen sulphur impurities are found in coal. The graphite particles still contain some mineral impurities, which are intercalated between stacks of adjacent graphene layers.
So, from the above explanation we can say that the correct answer is “C”.

Note: Activated charcoal has huge surface area and gives it countless bonding sites. When certain chemicals pass next to the carbon surface, they attach to the surface and are trapped. A good charcoal is mostly pure carbon, called ‘char’.