What is hydration enthalpy?

The Standard Enthalpy of Hydration, DH°hyd, 298, is the heat evolved when 1 mole of gaseous ions become hydrated (surrounded by water molecules), measured under standard conditions. The higher the charge on the ions and the smaller their size, the more exothermic the hydration enthalpy. read more

The heat energy released when new bonds are made between the ions and water molecules is known as the hydration enthalpy of the ion. The hydration enthalpy is the enthalpy change when 1 mole of gaseous ions dissolve in sufficient water to give an infinitely dilute solution. read more