The correct order of mobility of alkali metal ions in aqueous solution is

Options

A. `Li^(+)gtNa^(4)gtK^(+)gtRb^(+)`
B. `Na^(+)gtK^(+)gtRb^(+)gtLI^(+)`
C. `K^(+)gtRb^(+)gtNa^(+)gtLi^(+)`
D. `Rb^(+)gtK^(+)gtNa^(+)gtLi^(+)`

Answer

D

Explanation

As we go down the grop dissociation hydration energy of elements decreases. Thus the most mobile followed by `K^(+)gtNa^(+)gtLi^(+)`.
In group 1, `Li^(+)` will have highest hydration hydrated in aqeous solution & will thus be least.