Question

What is the order of mobilities of the alkali metal ions in aqueous solution?

• A. $L{i}^{+}>N{a}^{+}>K^{+}>C{s}^{+}>R{b}^{+}$
• B. $N{a}^{+}<L{i}^{+}<K^{+}<R{b}^{+}<C{s}^{+}$
• C. $L{i}^{+}>K^{+}>N{a}^{+}>R{b}^{+}>C{s}^{+}$
• D. $L{i}^{+}<N{a}^{+}<K^{+}<R{b}^{+}<C{s}^{+}$

Answer 1

The correct option is D $L{i}^{+}<N{a}^{+}<K^{+}<R{b}^{+}<C{s}^{+}$

As smaller the size of the ion, larger the charge of the ion hence greater the hydration and smaller ionic conductance and mobility of the ion. So the increasing order of mobility the alkali metal ions in aqueous solution is
$L{i}^{+}<N{a}^{+}<K^{+}<R{b}^{+}<C{s}^{+}$. Hence option D is correct.