The solubility of alkali metals salts in water is due to the fact that the cations get hydrated by water molecules. The degree of hydration depends upon the size of the cation. If the trend of relative ionic radii is `Cs^(+) gt Rb^(+) gt K^(+) gt Na^(+) gt Li^(+) `.
What is the relative degree of hydration?

Options

A. `Cs_((aq))^(+) gt Rb_((aq))^(+) gt K_((aq))^(+) gt Na_((aq))^(+) gt Li_((aq))^(+)`
B. `Li_((aq))^(+) gt Na_((aq))^(+) gtK_((aq))^(+) gt Rb _((aq))^(+) gt Cs_((aq))^(+)`
C. `Na_((aq))^(+) gt K _((aq))^(+) gt Rb _((aq))^(+) gt Cs_((aq))^(+) gt Li_((aq))^(+)`
D. `Cs_((aq))^(+) gt Na_((aq))^(+) gt Li_((aq))^(+) gt K_((aq))^(+) gt Rb_((aq))^(+)`

Answer

B

Explanation

Smaller the size of cation, greater is its charge density and greater is its hydration.