Bashyboy said:Ithought that this was the definiton for enthalpy of formation.
Internal energy is the total energy contained within a substance or system, including the sum of its kinetic and potential energies. It is a measure of the microscopic energy of the particles that make up the substance.
Enthalpy of formation is a thermodynamic quantity that measures the change in enthalpy when a substance is formed from its constituent elements. Internal energy, on the other hand, is a state function that represents the total energy of a system at a given temperature and pressure. While enthalpy of formation takes into account the energy required to break and form chemical bonds, internal energy includes all forms of energy within the system, such as kinetic and potential energy.
The internal energy of a substance is affected by its temperature, pressure, and composition. Changes in these factors can alter the kinetic and potential energies of the particles within the substance, thereby changing its internal energy.
Internal energy cannot be measured directly, but changes in internal energy can be measured through changes in temperature or pressure. The change in internal energy is also equal to the heat added to or removed from a system, as described by the first law of thermodynamics.
According to the law of conservation of energy, energy cannot be created or destroyed, but it can be converted from one form to another. Therefore, internal energy can be transferred into or out of a system, but it cannot be created or destroyed.