1. Plural of enthalpy; a measure of the total heat content of a substance or system, equal to the internal energy plus the product of pressure and volume.
Usage: technical; chemistry; thermodynamics

Examples

• The enthalpies of different chemical reactions can be compared to determine which releases more heat.
• In thermodynamics, scientists calculate the enthalpies of reactants and products to predict reaction spontaneity.
• The table lists the standard enthalpies of formation for common compounds.
• Measuring enthalpies helps engineers design more efficient heating and cooling systems.
• The enthalpies of phase transitions, such as melting and boiling, are important in materials science.