Question

The allotrope of carbon which is a good conductor of heat and electricity is:
A. diamond
B. sugar charcoal
C. graphite
D. wood charcoal

Answer 1

Hint:We know that a good conductor of electricity indicates that the compound has free electrons. When voltage is applied, these electrons can move from one atom to another atom. Some elements have different structural forms having different physical and chemical properties which are called allotropes.

Complete step by step answer:
Carbon belongs to the group two and period fourteen in the periodic table. It has a catenation property. It has the ability to bond with metals, nonmetals and metalloids.
From the given options, diamond and graphite are examples of allotropes of carbon. Both of them are very large molecules. Graphite has a planar structure. In graphite, one electron is free to move while three electrons share a covalent bond with the carbon atoms.
Even though diamond and graphite has different physical properties, they have almost the same chemical properties. Fullerene is also an example of allotrope of carbon. Sugar charcoal is the compound formed when the sugar molecules are burnt. It is the black residue of carbon. When sugar cane is distilled, we get sugar charcoal. We have seen this sugar charcoal in qualitative analysis of carbohydrates. When we add sulfuric acid to carbohydrates, it forms a black residue.
While wood charcoal is the soot produced when wood is burnt in the absence of air.
Since only graphite has free electrons, it is the good conductor of heat and electricity.

Hence, the correct option is C.

Note:
The following table given below shows the difference between diamond and graphite:

Diamond	Graphite
Carbon has ${{s}}{{{p}}^3}$ hybridization	Carbon has ${{s}}{{{p}}^2}$ hybridization
No free electrons are there	One free electron
Behaves as insulator	Good conductor of heat and electricity