Question

SiF²₆−

Number of Valence e- (Whole Structure)
Areas of e- Density Around Central Atom:
Electronic Geometry:

# Bonding Areas (Central Atom):
# Non-Bonding Areas (Central Atom):
Molecular Geometry

Bond Angles (Central Atom)

Polar Bonds?

Polar Molecule?

Any Pi (Double/Triple) Bonds?

Answer 1

The given molecule is .

Electronic configuration of Si =

Number of valence electron of Si = 4 e.

Electronic configuration of F=

Number of valence electrons = 7.

Since there are 6 F atoms, total valence electrons of F = 6*7 = 42 e.

There is a net charge of 2-, hence, that contributes extra 2 e.

Hence, Number of valence electrons of whole structure = 4+42+2 = 48 e.

Based on the Lewis structure,

# Areas of electron density around the central atom = 6

Electronic Geometry = Octahedral.

Si is forming sigma bond with each of the flourine atom.

Hence, # of bonding areas of central atom = 6.

# of non-bonding areas of central atom = 0.

Molecular geometry = Octahderal.

All the Si-F bond make 90 with each other about the central atom in octahedral geometry.

Bond angle (F-Si-F) = 90

Electronegativity of Si in Pauling's scale is about 1.9 whereas the same for F is about 4.

Hence, all the Si-F bonds are polar.

Polar Bonds? Yes, 6

Polar molecule? No

As the two Si-F bond dipoles on each spatial axis cancel the effect of the other as they are oriented opposite to each other. hence, the net dipole moment of the molecule is zero. making it non-polar.

Any Pi bond? No

Each F carry 6 electrons as lone pair, that is 36 e from 6 F. Remaining 12 electron are in the bond pairs, making the total 48. Hence, there is no more electron left to make any pi bonds.