Hydration enthalpy of cu2+ is high. Why ?

cu2+ has a smaller size than Cu+ as it contains 2 electrons less than Cu+.

so, due to its small size the charge of the ion remains concentrated and is not spread widely. due to this accumulation of charge , the polar water moleculescan easily make bonds with the Cu2+ ions and release a higher amount of energy , thus making the hydration enthalpy very high.