Answer to Question #3365 in Inorganic Chemistry for mujeeb rehman
Which element has greatest hydration energy, sodium ion or potassium ion?
In row Li+, Na+, K+, Rb+, Cs+ hydration energy decrease. This is due to increasing of ionic radius in this row. For sodium ions hydration energy is 406 kJ/mol and for potassium ions it is 322 kJ/mol. So, answer is sodium ion.