which of the following molecule is having least ionic character? (a) FeCl2 (b) ZnCl2 (C)MgCl2 (d)NaCl.
Dear student,
According to FAJAN's rule, the 18 electron system has more covalent character than 8 electron system. In ZnCl2, Zn+2 has 18 electrons in outer most shell which increases its stability and reduces its size drastically. The small size facilitates more charge density which in turn forces the electron cloud of anion to get shared with this cation thereby increasing the covalent character. Hence ZnCl2 is most covalent or in other words least ionic. In all other cases, the stability is of 8 electron system except FeCl2 where the cation is not that stable.
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According to FAJAN's rule, the 18 electron system has more covalent character than 8 electron system. In ZnCl2, Zn+2 has 18 electrons in outer most shell which increases its stability and reduces its size drastically. The small size facilitates more charge density which in turn forces the electron cloud of anion to get shared with this cation thereby increasing the covalent character. Hence ZnCl2 is most covalent or in other words least ionic. In all other cases, the stability is of 8 electron system except FeCl2 where the cation is not that stable.
Hope it helps
Regards