Question

How does the law of conservation of energy relate to Hess’s law?

Answer 1

To solve this we must know the law of conservation of energy and the Hess’s law. The Hess’s law states that the standard enthalpy of an overall reaction is the summation of the enthalpy changes in the individual reactions. The law of conservation of energy states that the total energy of an isolated system remains constant.

Complete solution:
remains constant and energy is said to be conserved over time. This means that energy can neither be created nor be destroyed and it can only be converted from one form to another.
We know that the Hess’s law states that the standard enthalpy of an overall reaction is the summation of the enthalpy changes in the individual reactions at the same temperature.
In simple words, Hess’s law states that the enthalpy change during a reaction is the same, whether a reaction takes place in one or several steps.
Thus, both the laws i.e. the law of conservation of energy and Hess’s law state that the energy is conserved.
Thus, the law of conservation of energy relates to Hess’s law.

Note: Hess’s law was given by chemist G. H. Hess. Hess’s law allows combining chemical equations to generate new chemical reactions whose enthalpy changes can be calculated rather than directly being measured. Hess’s law helps to calculate the heats of reactions which do not occur directly. Generally, Hess’s law helps in calculating heats of slow reactions.