Question

Find the number of lone pairs and bond pairs in$S{{F}_{6}}$.

Answer 1

The number of lone pair and bond pair can be calculated by identifying the Lewis dot structure of the given molecule. The number of lone pairs added with the number of bond pairs is equivalent to the valence electron around the atom.

Complete step by step solution:
Before calculating the number of lone pair and bond pair let’s understand what lone pair and bond pair means. A lone pair means a pair of valence electrons which is not shared with another atom. It is also known as an unshared pair or nonbonding pair of electrons.
When two atoms combine to form a covalent bond electrons are shared between both the atoms, these electrons which are present in the covalent bond are known as bond pairs.
Let’s start calculating the number of lone pair and bond pair by drawing the Lewis dot structure of $S{{F}_{6}}$.
First, we need to count the valence electrons, we can calculate it using the periodic table. Sulfur has 6 electrons in the valence shell and fluorine has 7 electrons in the valence shell.

Total valence electrons in $S{{F}_{6}}$= $6+6\left( 7 \right)=48$ valence electrons.

From the Lewis dot structure, we can conclude that there is 18 lone pair (3 on each fluorine and 0 on sulfur) and 6 bond pairs in the $S{{F}_{6}}$molecule.

Note: Note that sulfur can have expanded octet which means that it can have more than 8 valence electrons in the outermost shell. So for the structure of $S{{F}_{6}}$ there are 12 valence electrons on sulfur and 8 valence electrons on fluorine.