Chapter 8.3, Problem 49PP

Interpretation Introduction

Interpretation:

The Lewis resonance structure for ${\text{SF}}_{\text{6}}$ needs to be explained.

Concept introduction:

Lewis structure is also known as electron − dot structure which shows the bonding between atoms of a molecule and used for atoms to show their valence electron.

Explanation of Solution

Lewis structure is a representation of the valence electrons of an atom that uses dot around the symbol of the element, where number of dots around of the element are number of dots equal to the number of valence electrons in the atom.

Molecular formula formed when six fluorine atoms and one sulfur bond together ${\text{SF}}_{\text{6}}$

Valence electrons of S $=6$

$\text{F}=\text{7×6}=\text{42}$

Total $=42+6=48$

Out of 48, 12 eletrons will be involved in bonding as there are 6 S-F bonds. The reamaining 36 electrons will be presnet as lone pair of electrons on F atom. Therefore, each F atom will have 3 lone pair of electrons.

The Lewis dot structure is represneted as follows:

Sulfur Hexafluoride

For octet,

$\begin{array}{l}\text{S}=12\\ \text{F}=8\times 6=48\end{array}$

Total $=12+48=60$

Sulfur gets $12$ electrons and make $6$ bonds with $6$ fluorine atoms.

For bonding electron, $60-48=12e^{-}$

each bond is made up of $2e^{-}$ so the number of bonds.

$\frac{12e}{2}=6\text{ bond pair}$

then to find non - bonding (lone pair) electrons,

$48-12=36\text{ electrons = 18 lone pair of electrons}$

Conclusion

${\text{SF}}_{\text{6}}$ is having octehedral molecular geometry.

All the $\text{F}-\text{S}-\text{F}$ bonds are $90°$ degree it is not having lone pair electrons.