Chemistry - PERIODIC TABLE Question with Solution | TestHub

Ionic mobility is inversely proportional to the hydrated ionic radius. Smaller bare ions have a larger charge density, leading to stronger hydration and thus a larger hydrated radius. The order of bare ionic radii is Mg²⁺ < Ca²⁺ < Sr²⁺. Therefore, the order of hydrated radii is Mg²⁺ > Ca²⁺ > Sr²⁺, and the ionic mobility order is Sr²⁺ > Ca²⁺ > Mg²⁺.

The final answer is ${\mathrm{Sr}}^{+2}(\mathrm{aq})>{\mathrm{Ca}}^{2+}(\mathrm{aq})>{\mathrm{Mg}}^{2+}(\mathrm{aq})$.