Thermochemistry deals with the changes in heat during chemical reactions. The primary goal is to determine the quantity of heat exchanged between a system and its surroundings. The system is the part of the universe we are studying, while the surroundings is the rest of the universe that interacts with the system. A system and its surroundings can be as large as the rainforests in South America or as small as the contents of a beaker in your chemistry laboratory.
An NSF funded Project