Question

The correct order of conductivity of ions in water is ______.

Options

• Na⁺ > K⁺ > Rb⁺ > Cs⁺

• Rb⁺ > Na⁺ > K⁺ > Li⁺

• Cs⁺ > Rb⁺ > K⁺ > Na⁺

• K⁺ > Na⁺ > Cs⁺ > Rb⁺

Answer 1

The correct order of conductivity of ions in water is Cs⁺ > Rb⁺ > K⁺ > Na⁺.

Explanation:

As ions get larger, the hydration enthalpies of alkali metal ions fall down the group.

So, the ionic mobility in the aqueous solution increases as the mass of hydrated species decreases.

Thus, the order of conductivity of ions in H₂O is Cs⁺ > Rb⁺ > K⁺ > Na⁺