ABSTRACT
Chemical reactions involve the breaking and making of bonds, and physical processes involve the disruption or forming of intermolecular forces (IMFs). In both scenarios, the changes in bonds and IMFs lead to heat thermal energy transfer, heat. The thermal energy change associated per mole of reaction, the enthalpy of reaction (∆r H°), can be measured with calorimetry. The thermal energy change of a process can also be estimated by using standard thermochemical data: dissociation energy (E d), standard enthalpy of formation (∆f H°) values, and known enthalpy of reaction (∆r H°) values. In this chapter, readers will be introduced to the methods for calculating and estimating the enthalpy of a reaction, and they are provided with context for enthalpy's role in chemical research and its import in energy generation for humanity.
