The solubility of alkali metal 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 $C s^{+} > R b^{+} > K^{+} > N a^{+} > L i^{+}$ .
What is the relative degree of hydration?

C s_{(a q)}^{+} > R b_{(a q)}^{+} > K_{(a q)}^{+} > N a_{(a q)}^{+} > L i_{(a q)}^{+}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

L i_{(a q)}^{+} > N a_{(a q)}^{+} > K_{(a q)}^{+} > R b_{(a q)}^{+} > C s_{(a q)}^{+}

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

N a_{(a q)}^{+} > K_{(a q)}^{+} > R b_{(a q)}^{+} > C s_{(a q)}^{+} > L i_{(a q)}^{+}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

C s_{(a q)}^{+} > N a_{(a q)}^{+} > L i_{(a q)}^{+} > K_{(a q)}^{+} > R b_{(a q)}^{+}

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is B $L i_{(a q)}^{+} > N a_{(a q)}^{+} > K_{(a q)}^{+} > R b_{(a q)}^{+} > C s_{(a q)}^{+}$
Relative ionic radii $C s^{+} > R b^{+} > K^{+} > N a^{+} > L i^{+}$
As size increases hydration energy decreases. So relative degree of hydration is
$L i^{+} > N a^{+} > K^{+} > R b^{+} > C s^{+}$
Thus, $L i^{+}$ have maximum degree of hydration and thus lithium salts are mostly hydrated.

Suggest Corrections

Similar questions

{C s}_{a q}^{+} < {R b}_{a q}^{+} < K_{a q}^{+} < {N a}_{a q}^{+}

ionic species having largest size:

A. Li+(g)

B.Na+ (aq)

C. Rb+(aq)

D. Li+(aq)

N a_{(a q)}^{+}

K_{(a q)}^{+}

r_{N a^{+} (a q)} > r_{k^{+} (a q)}

L i^{+} (a q .)

L i^{+} (a q .)

N a C l (s) + a q ⟶ N a^{\oplus} (a q) + C l^{⊖}

Δ H = 3.9 k J

N a^{\oplus} (g) + C l^{⊖} (g) ⟶ N a C l (s) Δ H = - 788 k J

C l^{⊖} (g) + a q ⟶ C l^{⊖} (a q) Δ H = - 394.1 k J

N a^{\oplus}

Join BYJU'S Learning Program