Reaktionswärme

Reaktionswärme, also known as enthalpy of reaction, refers to the heat energy absorbed or released during a chemical reaction. This heat change is a fundamental aspect of thermochemistry and is a measure of the enthalpy difference between the products and the reactants. The unit for measuring Reaktionswärme is typically joules (J) or kilojoules (kJ), often expressed per mole of a specific reactant or product.

If a reaction releases heat into its surroundings, it is termed exothermic, and its Reaktionswärme is negative. Conversely, if a reaction absorbs heat from its surroundings, it is endothermic, and its Reaktionswärme is positive. The magnitude of the Reaktionswärme is directly related to the strength of the chemical bonds being broken and formed during the reaction. Stronger bonds require more energy to break, and stronger bonds are formed when products are more stable than reactants, contributing to a larger heat release or absorption.

The standard Reaktionswärme refers to the heat change when a reaction occurs under standard conditions, typically defined as 298.15 Kelvin (25 degrees Celsius) and 1 atmosphere of pressure. Understanding Reaktionswärme is crucial in various fields, including chemical engineering for process design and optimization, as well as in understanding biological processes.