Question

Size of hydrated ion of $L{i}^{+}andB{e}^{2+}$ is :

• A. $L{i}^{+}<B{e}^{2+}$
• B. $L{i}^{+}>B{e}^{2+}$
• C. $L{i}^{+}=B{e}^{2+}$
• D. None of these

Answer 1

The correct option is A $L{i}^{+}<B{e}^{2+}$

The hydration energies of alkali metal ions decrease with increase in ionic size. The size of alkali metal ions in aqueous solution(hydrated ion) is in the following order $C{s}^{+}<R{b}^{+}<K^{+}<N{a}^{+}<L{i}^{+}$

so as the size of the ion increases the hydrated ion size decreases.

So the correct order $L{i}^{+}<B{e}^{2+}$ Hence, option A is correct,