Question

Considering greater polarisation in $LiCl$ compared to that in $NaCl$, which of the following statement is wrong?

• A. Fused $LiCl$ would be less conducting than fused $NaCl$
• B. The melting point of $LiCl$ is lower than that of $NaCl$
• C. $LiCl$ dissolves more in organic solvent than $NaCl$
• D. $LiCl$ would ionise in water more than $NaCl$

Answer 1

The correct option is D $LiCl$ would ionise in water more than $NaCl$

The ionic size of $L{i}^{+}$ cation is smaller than the ionic size of $N{a}^{+}$ cation. Hence, the polarization in $LiCl$ is more than that in $NaCl$. Due to this, the covalent character in $LiCl$ is greater than the covalent character in $NaCl$. So, the extent of ionization in $LiCl$ is smaller than the extent of ionization in $NaCl$.
Lower ionization results in lower conductivity of $LiCl$ in fused state.
Due to greater covalent character, the solubility of $LiCl$ is higher than that of $NaCl$.
This also results in lower melting point of $LiCl$ $\left({605}^{o}C\right)$ than that of $NaCl$ $\left({801}^{o}C\right)$.