Question

Which of the following has highest boiling point?

• A. $NaCl$
• B. $CaC{{l}_{2}}$
• C. $MgC{{l}_{2}}$
• D. $AlC{{l}_{3}}$

Answer 1

Answer: (A)

$NaCl$

Answer 2

$NaCl$ has highest boiling point as it is the most ionic among these. According to Fajans rule, greater the charge on cation, greater will be its polarizing power. Hence, $A{{l}^{3+}}$ polarise $C{{l}^{-}}$ ions to much extent and consequently, it is partly covalent while $NaCl$ is much ionic