The correct order of hydration enthalpies is
(A) K$^+$
(B) Rb$^+$
(C) Mg$^{2+}$
(D) Cs$^+$
(E) Ca$^{2+}$
Choose the correct answer from the options given below :
Solution
Hydration enthalpy $\propto$ charge density
<br/><br/>Charge density means ${{Magnitude\,of\,Charge} \over {Ionic\,Radius}}$.
<br/><br/>
$\therefore$ The correct order of charge density is
<br/><br/>
$\mathrm{Mg}^{2+}>\mathrm{Ca}^{2+}>\mathrm{K}^{+}>\mathrm{Rb}^{+}>\mathrm{Cs}^{+}$
<br/><br/>
$\therefore$ The order of hydration enthalpy
<br/><br/>
$C>E>A>B>D$
About this question
Subject: Chemistry · Chapter: s-Block Elements · Topic: Alkali Metals
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