Final answer:
Lisa is working within the field of thermochemistry, specifically using calorimetry to measure the heat released during chemical reactions. Calorimetry allows her to calculate heat change by measuring the temperature change of an insulated system after a reaction occurs.
Step-by-step explanation:
Lisa, a chemist, is conducting a series of reactions to measure the amount of heat being released in each one. This area of chemistry would best fit within thermochemistry, which is the study of energy changes that occur during chemical reactions and changes in state. The technique she is using, known as calorimetry, involves measuring the heat transfer associated with chemical reactions or physical processes.
During calorimetry, the chemist pre-measures the mass of chemicals within a system, allows the reaction to occur, and then measures the system's temperature change. This information, coupled with the known specific heat of the materials, is used to calculate the heat change (q), which corresponds to the enthalpy change (ΔH) of the reaction.
The calorimeter, typically an insulated container, ensures any energy change results in temperature change of the system rather than being lost to the environment. Through these measurements and calculations, Lisa can determine the thermal energy released or absorbed during the reactions, contributing significantly to our understanding of the reactions' energetic properties.