calorimeter
The subfield of thermochemistry studies the energy changes that occur over the course of various chemical reactions. We will first look at how these changes are measured and then go into quantitative descriptions of heat transfer. Calorimetry is a term used to describe the measurement of heat transfers, usually by monitoring changes in the temperature of an isolated system. A calorimeter is a device used to measure temperature changes during chemical processes. The simplest type of calorimeter is the constant-pressure device illustrated in Figure below .