Question

Which of the alkali metal chloride (MCl) forms its dihydrate salt $\left(MCl\cdot 2H_{2}O\right)$ easily?

• A. $LiCl$
• B. $CsCl$
• C. $RbCl$
• D. $KCl$

Answer 1

Answer: (A)

The size of the ion and its charge determines extent of hydration. Greater the charge and smaller the size of ion, greater is the extent of hydration and, hence greater is the hydration enthalpy.
Thus, $L{i}^{+}$having maximum hydration tendency, forms dihydrate salt $\left(LiCl.2H_{2}O\right)$ easily.