standardentalpia
Standard enthalpy, denoted ΔH°, is the heat content change of a chemical process carried out under defined standard conditions. In chemistry, the standard state is typically 1 bar (often approximated to 1 atm) and a reference temperature of 298.15 K. The standard enthalpy change of a reaction is independent of the pathway taken, by Hess's law, and reflects the net heat absorbed or released when reactants in their standard states form products in their standard states.
The standard enthalpy of formation, ΔH°f, is a related quantity: it is the enthalpy change when one
Enthalpies of reaction can be computed from tabulated ΔH°f values: ΔH°rxn = sum of coefficients × ΔH°f(products)
Standard enthalpy values are widely used in chemical thermodynamics to predict reaction feasibility, balance energy budgets