Question

Assertion: Carbon and its compounds used as fuels for most applications.
Reason: When carbon is heated in presence of excess of air or oxygen, it forms carbon dioxide. During its formation, a large amount of heat and light are released. Further once ignited, carbon and its compound keeps on burning without needing additional energy.
A. Both assertion and reason are correct and reason is the correct explanation of assertion.
B. Both assertion and reason are correct but reason is not the correct explanation of assertion.
C. Assertion is correct but reason is incorrect.
D. Assertion is incorrect but reason is correct.

Answer 1

Carbon is a chemical element represented by the symbol C having atomic number 6. It belongs to the 14th group of periodic tables and is found as the 15th most abundant element in the earth’s crust and it has three naturally occurring isotopes.

Complete answer:
Carbon and its compounds are generally known to us because of its application in fuels like coal, petroleum, CNG etc. These are used as fuels due to following reasons:
1. Carbon compounds give large amounts of heat while combustion as there is a high percentage of carbon and hydrogen in these.
2. These compounds also have optimum ignition temperature with high calorific values and these are known as good fuel due to these properties and are also easy to handle.
3. Their combustion can also be controlled. Therefore carbon and its compounds are used as fuels.
This is also true that when carbon is heated in presence of excess air or oxygen it forms carbon dioxide and burns with clean flame having no smoke. During its formation a large amount of heat and light are released. Further once ignited carbon and its compound keeps on burning without needing additional energy.

Hence from the above discussion we can conclude that option A is the correct answer.

Note: Ignition temperature is that minimum temperature at which a substance starts burning and any substance which is below from its ignition temperature will not allow itself to burn. LPG, CNG, petrol etc are substances having low ignition temperature while wood and charcoal have high ignition temperature.