Question

$[SiF_{6}}]^{2-}$ is known whereas $[SiCl_{6}}]^{2-}$ is not. Give possible reasons.

Answer 1

Chlorine and fluorine atoms are generally called as halogens. Halogens are placed in group 17. Halogens reacts with other elements to form respective halides. $Si{ f }_{ 6 }^{ 2- }$ is known and $Si{ Cl }_{ 6 }^{ 2- }$not known because, Atomic size of fluorine atom is small compared to chlorine atom. Hence, fluorine atoms are easily arranged around silicon when compared to chlorine.

And also chlorine atom creates steric hindrance between silicon and chlorine atoms.

Hence $Si{ Cl }_{ 6 }^{ 2- }$ cannot exist.

Answer 2

$\huge\boxed{\underline{\mathcal{\red{A}\green{N}\pink{S}\orange{W}\blue{E}\purple{R}}}}$

❤⭐MAIN REASONS:- ⭐❤

1. six large chloride ions cannot be accomodated around ${Si}^4+$ due to $\purple{\tt{Limitation}}$of its size.
2. Interaction between lone pair of chloride ion and${Si^4+}$ is not very strong.