Question

What is the Calorific value?
(A). Amount of heat energy produced on complete combustion of $1$ Kg of fuel.
(B). Amount of heat energy produced on complete combustion of $100$ Kg of fuel.
(C). Amount of heat energy produced on complete combustion of $1$ g of fuel.
(D). Amount of heat energy lost on complete combustion of $1$ Kg of fuel.

Answer 1

Every compound on burning or combustion releases energy. The release of energy in any reaction is named an exothermic reaction. Some reactions require extra energy so that the reaction is carried out; they are named endothermic reactions. The net gain and loss of reaction are always zero in nature.

Complete answer:
A reaction is a phenomenon in which the initial materials (reactants) are converted to the final materials (products). Examples of reactions include digestion of food by an organism, freezing of water, and many more. In any reaction, there is use or the release of energy. On the basis of the use or release of energy, we can classify a reaction into exothermic and endothermic reactions.
The energy released during combustion is calculated in terms of Calorific value, which is defined as the amount of heat energy produced on complete combustion of $1$ Kg of fuel. Thus, the correct answer is (A). Amount of heat energy produced on complete combustion of $1$ Kg of fuel.

Note:
On the basis of energy use and loss, we can classify the reactions into two types, one is exothermic and the other is exothermic. Exothermic reactions are those particular types of reactions in which the heat or the energy is released out from the system like burning, combustion, and many more. Whereas endothermic reactions are those particular types of reactions in which the heat or the energy is to be supplied from the external source like the excitation of an electron in a molecule, melting of ice, and many more.