question_answer

Alkaline earth metals always form divalent cations even though their second ionization enthalpies are almost double than their first ionization enthalpies. Explain.

Answer:

                In the solid state, higher enthalpy of lattice formation by \[{{M}^{2+}}\] ions (as compared to \[{{M}^{+}}\] ions) more than compensates the higher second ionization enthalpies of metals and in aqueous solution, higher enthalpy of hydration of\[{{M}^{2+}}\] ions (as compared to \[{{M}^{+}}\]ions) more than compensates the higher second ionization enthalpy of metals.