### Chemistry Formulas

# Enthalpy Formula

You must be aware of the fact that the heat is released or absorbed by a body is the concept of internal energy. The total amount of heat absorbed is equal to the total change in the internal energy. It can be given by ∆U = qV in Chemistry. The equation holds amazing when the volume is constant.

The alternative solution to the problem is to carry out the reactions at the constant pressure either in test tubes or flasks. This is the reason why do we need another state function that defines the change in internal energy at the constant pressure. Here is how the concept of Enthalpy comes into the picture.

*So, what is Enthalpy and why is it needed in Chemistry?*

Enthalpy is a popular thermodynamic function that is equal to the sum of total internal energy and the product of the pressure or volume. The Enthalpy formula can be given as follow –

#### H = E + PV

Based on this formula, H is the Enthalpy, E is the internal energy, P is the pressure, and V is the Volume. This is complicated finding the total internal energy of system but the changes in internal energy can be calculated. So, delta symbol is added with H and ΔH refers to the change.

There are multiple techniques for finding the ΔH in Chemistry. Scientists are using change in temperature value over the time to find the Enthalpy. A little practice and understanding of the concept make you proficient in the Chemistry.