Hess law is corrolary of first law of thermodynamics-explain
Answers
Hess' law states that the change of enthalpy in a chemical reaction (i.e. the heat of reaction at constant pressure) is independent of the pathway between the initial and final states. Hess' law allows the enthalpy change (ΔH) for a reaction to be calculated even when it cannot be measured directly.
The First Law of Thermodynamics states that heat is a form of energy, and thermodynamic processes are therefore subject to the principle of conservation of energy. This means that heat energy cannot be created or destroyed. It can, however, be transferred from one location to another and converted to and from other forms of energy.
The mathematical representation of the first law of thermodynamics is:
△U = Q + W
Where,
ΔU is the total change in the internal energy of the system
Q is the heat exchanged between the system and its surroundings
W is the work done either by the system or on the system