The correct order of increasing covalent character of the following is

Options

A. `SiCl_(4)ltAlCl_(3)ltCaCl_(3)ltKCl`
B. `KClltCaCl_(2)ltAlCl_(3)ltSiCl_(4)`
C. `AlCl_(3)ltCaCl_(2)ltKClltSiCl_(4)`
D. None of the above

Explanation

(b) EN difference in `SiCl_(4)`= 3.0-1.8=1.2
in `AlCl_(3)` = 3.0-1.5=1.5
in `CaCl_(2)`= 3.0-1.0=2.0
in KCl = 3.0-0.8=2.2
`:. KCl lt CaCl_(2) lt AlCl_(3) lt SiCl_(4)`
This order is also obtained by applying Fajan's rule. i.e. convalent character prop charge on io.