Question

Define enthalpy of combustion.

Answer 1

Hint : Combustion is a reaction in which a substance or compound is burned in the presence of air. This reaction happens when a compound burns in the presence of oxygen. Enthalpy of combustion is referred to as the heat produced in the combustion reaction. In the solution we will see the detailed explanation about enthalpy of combustion.

Complete Step By Step Answer:
We know that combustion is a reaction in which a substance or compound is burned in the presence of air. This reaction happens when a compound burns in the presence of oxygen. Enthalpy is also known as heat. It is studied under the branch of chemistry known as Thermochemistry. There are many different kinds of enthalpies for different types of reactions.
Enthalpy of combustion is referred to as the heat produced in the combustion reaction which means that it is the heat involved in the combustion reaction and all the reactants are present in their standard states. Generally the combustion reaction is an exothermic reaction which means heat is released during this process.
We should also remember that standard enthalpy of combustion is known as the amount of heat evolved when one mole of a compound is burned in presence of excess oxygen and all the reactants are present in their standard states.

Note :
We must note that while calculating the enthalpy of the reaction, the reactants must be in their standard states and if the compound is present in solid state, then its enthalpy is always considered as zero. There are many more enthalpies such as the enthalpy of sublimation, formation, hydration and so on.