Final answer:
The formula to calculate the standard enthalpy change (ΔH°) is derived from the relationship ΔH° = ΔG° + TΔS°, using the standard free energy change (ΔG°), the temperature in Kelvin (T), and the standard entropy change (ΔS°).
Step-by-step explanation:
The formula for calculating the standard enthalpy change (ΔH°) is key to understanding thermodynamic processes in chemistry. The general formula for calculating the standard change in enthalpy is typically derived from the standard heats of formation or from bond energies. However, when directly involved with changes in free energy, the relevant formula to calculate ΔH° appears in the equation ΔG° = ΔH° - TΔS°, where ΔG° is the change in standard free energy, T is the temperature in Kelvin, and ΔS° is the standard entropy change. When calculating ΔH°, it is possible to rearrange this formula to ΔH° = ΔG° + TΔS° if ΔG° and TΔS° are known or can be determined through experimental measurements or tabulated data.