Which one of the following is a covalent molecule?

To a mixture of $LiCl$,$AlCl_3$ and $NaCl$,ether is added. Which of these will be extracted into ether?

Amongst $LiCl$,$RbCl$,$BeCl_2$,and $MgCl_2$,the maximum and minimum ionic character will be shown by the compounds:

Which of the following is the correct decreasing order of the melting points of calcium halides?

Which is the correct decreasing order of polarizability of the following ions?

How many of the following orders of covalent character are $TRUE$?
$(i)$ $LiF < LiCl < LiBr < LiI$ (Fajans' rule: covalent character increases with increasing size of anion)
$(ii)$ $CaCl_2 < FeCl_2 < FeCl_3$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iii)$ $Hg_2Cl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing charge on cation)
$(iv)$ $ZnCl_2 < CdCl_2 < HgCl_2$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(v)$ $CuCl < AgCl < AuCl$ (Fajans' rule: covalent character increases with increasing polarizability of cation)
$(vi)$ $AlN > Al_2O_3 > AlF_3$ (Fajans' rule: covalent character increases with increasing charge on anion)
$(vii)$ $CaF_2 < CaCl_2 < CaBr_2 < CaI_2$ (Fajans' rule: covalent character increases with increasing size of anion)