Question

The correct order of conductivity of ions in water is

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

Answer 1

The correct option is C

$C{s}^{+}>R{b}^{+}>K^{+}>N{a}^{+}$

The alkali metal ions in aqueous solution get hydrated. The extent of hydration of an ion is directly proportional to its charge density. The size of hydrated metal is decreases down the group and hence their mobility increases or their conductivity increases. Thus The correct order of conductivity of ions in water is $C{s}^{+}>R{b}^{+}>K^{+}>N{a}^{+}$