Thermochemistry is a branch of chemistry that studies the heat changes that occur during chemical reactions and physical processes. It focuses on understanding how energy, particularly in the form of heat, is absorbed or released when substances react, dissolve, or change states (like melting, boiling, or condensing).
Key points about thermochemistry:
- Exothermic processes: Reactions or processes that release heat to the surroundings (e.g., combustion of fuel).
- Endothermic processes: Reactions or processes that absorb heat from the surroundings (e.g., photosynthesis).
- Energy changes: Thermochemistry measures changes in enthalpy (ΔH), which indicates the total heat content change during a reaction at constant pressure.
- Applications: It helps in predicting reaction feasibility, calculating energy requirements for chemical processes, and understanding fuels, batteries, and biochemical reactions.
In simple terms, thermochemistry is all about how energy flows in the form of heat during chemical reactions and physical changes.