[SiF_(6)]^(2-)is knownwheares [SiCl_(6)]^(2-)not. Givepossiblereasons.

1.	[SiF_(6)]^(2-)is knownwheares [SiCl_(6)]^(2-)not. Givepossiblereasons.
Answer» Solution :The mainreasons are : (i) Due to smallersize ofF as comparedto Cl, six SMALL Fatoms can be easily accomodatedaround Si atom but six largeCl atoms cannot. (II) The lone PAIR of electrons on F are present in a smaller 2p-orbitalbut in Cl they are present on a LARGER 3p-orbital.Therefore, interaction of F lone pair electrons with d-orbitalsof siliconare stronger than that of Cl lone pairs.

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