Which of the following is the most covalent in nature ?

Options

A. LiF
B. LiCI
C. LiBr
D. LiI

Answer

D

Explanation

The distortion of electron cloud of the anion by the cation is called polarization. The `Li^(+)` ion is very small in size and has high tendency to distort electron cloud around the halide ion. Because of the high polarization capability of `Li^(+)` ion, lithium halides are somewhat covalent. Since anion with large size can be easily distorted, among halides, LiI is the most covalent in nature. The order of covalent character is `LiI gt LIBr gt LiCI gt LiF` because larger the anion, greater is its polarizability. For the same reason, the dipole moment of LiI (0.25 D) is much leass than the excepted value (11.5 D) if it were 100% ionic.