Question:

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

Updated On: Jul 26, 2024
  • $ Li^+ > Na^+ > K^+ > Rb^+ $
  • $ Na^+ > K^+ > Rb^+ > Li^+ $
  • $ K^+ > Rb^+ > Na^+ > Li^+ $
  • $ Rb^+ > K^+ > Na^+ > Li^+ $
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is D

Solution and Explanation

Charge density $\propto$ hydration. Therefore hydrated
size of $Li ^{+}$ is large and having less mobility. Down the group degree of hydration decreases.
Was this answer helpful?
0
0

Concepts Used:

Group 1 Elements

Group one of alkali metals is s-block elements with just one electron in their s-orbital. They are are alkali metals. They are named so because of the alkaline nature of the hydroxides and oxides.

Alkali metals are characterized by one s-electron in the valence shell of their atoms.

Alkali metals have a corresponding [Noble gas] ns1 electronic configuration. They occupy the first column of the periodic table. Alkali elements are:

  • Lithium(Li)
  • Sodium(Na)
  • Potassium (K)
  • Rubidium (Ru)
  • Cesium (Cs)
  • Francium (Fr)

They have occupied successive periods from first to seven. Francium is a radioactive element with very low half-life.

Electronic Configuration:

  • Alkali metals have one electron in their valence shell.
  • The electronic configuration is given by ns1. For example, the electronic configuration of lithium is given by 1ns1 2ns1.
  • They tend to lose the outer shell electron to form cations with charge +1 (monovalent ions).

This makes them the most electropositive elements and due to the same reason, they are not found in the pure state.