Question

The order of ionic conductance of alkali metal ions in their aquous solution in a given concentration is

• A. $Li^{+} < Na^{+} < K^{+} < Rb^{+}$
• B. $Li^{+}>Na^{+}>K^{+}>Rb^{+}$
• C. $Li^{+} < Na^{+}>K^{+}>Rb^{+}$
• D. $Li^{+}=Na^{+} < K^{+} < Rb^{+}$

Answer 1

Answer: (A)

The smaller cation have higher charge and greater extent of hydration, thus lesser will be ionic conductance and mobility. With the increase in size of cation the size of the hydrated ion decreases, hence ionic conductance increases.