How is thermochemistry used in my freezer?
The appropriate term here is thermodynamics, which basically how quickly a system can absorb or release heat.
The first law of thermodynamics states that heat will always flows from a hot to cold source.
In a refrigerator, a system known as a heat engine is used where heat from the surrondings enters the freezer. However, the main purpose of a freezer is to preserve food items under low temperatures.
Therefore, the system works by transforming the heat energy from the surrondings and transforming it into cold air in the freezer. However, this process is not 100% effective as there are bound to be some remaining heat outside.