Question

Which of the following statements about $LiCl$ and $NaCl$ is wrong?

• A. $LiCl$ has lower melting point than $NaCl$
• B. $LiCl$ dissolves in organic solvent whereas $NaCl$ does not
• C. $LiCl$ would ionize in water more than $NaCl$
• D. Fused $LiCl$ would be less conducting than fused $NaCl$

Answer 1

Answer: (C)

$LiCl$ would ionize in water more than $NaCl$

$LiCl$ has a lower melting point than $NaCl$ (as $LiCl$ has a covalent character according to Fagan's rule, whereas a strong ionic bond holds $NaCl$). Thus, the first option is correct.

Covalent molecules dissolve in polar organic solvents, whereas ionic molecules do not. Hence, $LiCl$ dissolves in organic solvents, but $NaCl$ does not. Because $LiCl$ has covalent character, (and greater polarization) and $NaCl$ does not. So, this option is also correct.

Ionic compounds ionize to a greater extent. $NaCl$ is more ionic than $LiCl$, which is having a covalent character. Thus, $NaCl$ ionizes more than $LiCl$, so this option is incorrect.

Fused $NaCl$ conducts more electricity than fused $LiCl$ because there is more flow of ions in $NaCl$ (when it is molten and the lattice energy is decreased). Hence, this option is also correct.