Allotropes of Carbon: Overview, Questions, Preparation

The occurrence of more than one physical form is acceptable and common. Diamond and graphite are the two elements that have the same carbon atoms present. However, the difference can be seen in lieu of the bonding structure of both the elements. Diamond bonding structure is a three-dimensional structure, and the bonding structure of graphite is hexagonal. The structural representation of graphite is:

Diamond and Graphite

Some of the most important properties of Diamond and Graphite can be shown in the tabular form:

Some of the more properties of diamond are as follows –

1. Diamond is a bad conductor of electricity
2. It is insoluble
3. It has a high density
4. It has a high refractive index
5. It is transparent to cathode rays

More properties of graphite are listed below –

1. The atrophy in the carbon in graphite acts as a lubricant
2. It is a good conductor of electricity because of its metallic lustre
3. It is a good conductor of heat
4. Thermodynamically, graphite is more stable compared to diamond

Other allotropes of carbon

1. Fullerenes: Fullerenes are round in shape. The composition of C2n is present in this, where n ≥ 30. The components present in this can be evaporated with a laser. Some carbon atoms are sp2, and C20 which are often called 'BuckminsterFullerene'.
2. Silicates: sp3 hybridised is present in silicon. The allotropes of carbons in silicates are designed and classified according to the structure. Some famous silicates are:

• Orthosilicates
• Pyro silicates
• Cyclic silicates
• Chain silicates
• Two-dimensional silicates
• Three-dimensional silicates

3. Buckminster Fullerenes: Buckminsterfullerene is the C60 fullerene. The shape of Buckminsterfullerene is in a ball shape the same as football

Allotropes of carbon for class 10

For the year 2021, chapter carbons and their compounds hold a weightage of 5 marks in total. It includes one short type of question carrying 1 mark and one very-short question carrying one mark each as well.  The topic of 'allotropes of carbon' is not vast, but it is crucial for the understanding of advanced topics related to Carbon.

Illustrated Examples

Example 1) Name two allotropes of carbon other than diamond and graphite.

Answer – Graphene and BuckminsterFullerene are the other two allotropes of carbon.

Example 2) state the name of the element which has the highest number of allotropes.

Answer – Phosphorous has the highest number of allotropes, and it exists in 6 forms.

Example 3) Find the element which is not an allotrope of a carbon:

1. Diamond
2. Graphite
3. Carbon dioxide
4. Charcoal

Answer – The correct answer is c. carbon dioxide. Carbon dioxide is a gas, and it doesn't fall under the category of allotropy.

Q. What is the density of diamond?

Q. Which crystal class does the graphite specimen belong to?

Q. Which element is the hardest form of allotrope?

Q. Is coke considered an allotrope?

Q. What is the purest form of carbon?