Calorific Value of Carbon

Calorific value, also known as heat of combustion, is the amount of heat energy released when a substance undergoes complete combustion with oxygen. In the case of carbon, the calorific value refers to the heat energy released when one gram of carbon is burned completely.

The correct answer to the given question is option 'C', Calorific Value of carbon. Let's understand why this is the correct answer.

Explanation:

1. Heat of Combustion of Carbon:
- The heat of combustion of carbon refers to the amount of heat energy released when one mole of carbon atoms is burned completely.
- It is a thermodynamic property that represents the enthalpy change during the combustion process.
- However, the given question specifically asks for the heat product in calories by the combustion of 1 gram of carbon, which is not the same as the heat of combustion of carbon.

2. Heat of Formation of Carbon:
- The heat of formation of carbon refers to the heat energy change that occurs when one mole of carbon is formed from its constituent elements in their standard states.
- It is a measure of the stability of carbon compared to its constituent elements.
- The heat of formation is not directly related to the combustion of carbon or the heat energy released during combustion.

3. Calorific Value of Carbon:
- The calorific value of carbon is the heat energy released when 1 gram of carbon is burned completely in excess oxygen.
- It is a measure of the energy content of carbon and is often expressed in calories or joules per gram.
- The calorific value is a practical measure used to determine the energy potential of carbon-containing fuels like coal, wood, and fossil fuels.

Conclusion:
The correct answer to the question is option 'C', Calorific Value of carbon, because it accurately describes the heat product in calories by the combustion of 1 gram of carbon. The heat of combustion of carbon and the heat of formation of carbon are not directly related to the given question.