Question

Distinguish between diamond and graphite.

Answer 1

Hint: Mention their physical as well as chemical properties. Describe their structures.

Complete answer:
It is very common knowledge that both diamond and graphite are allotropes of carbon. Allotropes are compounds which are chemically the same but significantly vary in their physical properties. Before differentiating them, let us look at carbon first. It belongs to the second period and fourteenth group of the atomic table. It is therefore a metalloid which means its electronegativity and electropositivity are well balanced. As it is the first member of its group, carbon is the smallest among them and does not have d-orbitals. All of these properties make it an element which has the highest self-linking property among all the other elements in the periodic table. It is also able to form strong bonds with metals, nonmetals and metalloids. Diamond and graphite are large molecules of carbon which do not have a specific formula. Their size completely depends on the extent of their physical structures.
The table below summarizes the differences between diamond and graphite.

DIAMOND

GRAPHITE

1. The hybridisation of carbon here is $s{{p}^{3}}$. Therefore it has a tetrahedral structure. 2. All four valencies of carbon atoms are satisfied. 3. Behaves as an insulator because there are no free electrons for the conduction of electricity.4. It has a crystal structure and therefore is very hard.5. The molecular arrangement of the carbon molecules are three dimensional in nature because of the tetrahedral geometry.

1. The hybridisation of carbon is$s{{p}^{2}}$. The structure is trigonal planar. 2. Only three valencies of carbon are satisfied.3. Can conduct electricity because it has one free electron per$s{{p}^{2}}$hybridised carbon.4. It is soft in nature and can easily fall apart.5. The molecular arrangement is actually two dimensional forming a plane of carbon atoms with trigonal planar geometry. These planes are then stacked above one another without any strong bonding between them.

Note: Although both diamond and graphite have many significant physical differences, they are same in many chemical properties which more involve the fact that they are composed of the same element than their macrostructure and other conditions that gave birth to their physical differences.
Both of them are insoluble in organic solvents and also in polar solvents such as water. This is due to the fact that the covalent bonds are stronger and the energy released when they bond with water is far inferior to that.