Question

The chloride of Hg+ is covalent while it's fluoride is ionic. Explain.long

Answer 1

Explanation:

HgCl is covalent while HgF is ionic can be explained on the basis of FAJAN'S RULE ...

for this we look polarising power of CATION and polarisibilty power of ANION

as cation is same in both the cases so palarising power is same in both the compounds but what is varying is the ANION . and the polarisibilty of ANION increases with incr. in size so incr down the group. and as the polarisibilty incr covalent character incr in a bond