Question

Which of the following species is not stable?
(1) [SiF
6
]
2–
(2) [GeCl
6
]
2–
(3) [Sn(OH)
6
]
2–
(4) [SiCl
6
]
2–

Answer 1

Question: Which of the following species is not stable?

(1) $[Sif_6]^{2-}$

(2) $[GeCl_6]^{2-}$

(3) $[Sn(OH)_6]^{2-}$

(4) $[SiCl_6]^{2-}$

Solution: (4) $[SiCl_6]^{2-}$

Explanation: Due to the presence of d-orbital in Si, Ge, and Sn they form species like $SiF_6\:^{2-}$, $GeCl_6\:^{2-}$, $Sn(OH)_6\: ^{2-}$.

$SiCl_6\:^{2-}$ does not exist because six large chloride ions cannot be accommodated around $Si^4^+$ due to limitation of its size.