Question

By Pajan's rule covalent character increases with increase in size of the anion. Identify the correct order of melting point of calcium.

• A. $ Ca{{F}_{2}} < CaC{{l}_{2}} < CaB{{r}_{2}} < Ca{{I}_{2}} $
• B. $ CaC{{l}_{2}} < Ca{{F}_{2}} < CaB{{r}_{2}} < Ca{{I}_{2}} $
• C. $ Ca{{F}_{2}}>CaC{{l}_{2}}>CaB{{r}_{2}}>Ca{{I}_{2}} $
• D. $ CaC{{l}_{2}}>Ca{{F}_{2}}>CaB{{r}_{2}}>Ca{{I}_{2}} $

Answer 1

Answer: (C)

According to Fajan's rule, Covalent character
$\propto$ size of anion $\propto \frac{1}{\text { melting point }} $
$(\because$ Attraction decreases $)$
Thus, the order of melting point is
$CaF _{2}> CaCl _{2}> CaBr _{2}> CaI _{2}$