The Lewis structure of SF2 contains two single bonds, with sulfur in the center, and two fluorines on either side. There are three lone pairs on each fluorine atom, and two lone pairs on the sulfur atom.
Steps
By using the following steps, you can easily draw the Lewis structure of SF2:
#1 Draw skeleton
#2 Show chemical bond
#3 Mark lone pairs
#4 Calculate formal charge and check stability (if octet is already completed on central atom)
Let’s one by one discuss each step in detail.
#1 Draw skeleton
In this step, first calculate the total number of valence electrons. And then, decide the central atom.
- Let’s calculate the total number of valence electrons
We know that… sulfur is a group 16 element and fluorine is a group 17 element. Hence, sulfur has six valence electrons and fluorine has seven valence electrons.
Now SF2 has one sulfur atom and two fluorine atoms.
So the total number of valence electrons = valence electrons of sulfur atom + (valence electrons of fluorine atom × 2)
Therefore, the total number of valence electrons = 6 + 14 = 20
- Now decide the central atom
The atom with the least electronegative value is placed at the center. By looking at the periodic table, we get the electronegativity values for sulfur and fluorine as follows:
Electronegativity value of sulfur = 2.58
Electronegativity value of fluorine = 3.98
Obviously, sulfur is less electronegative than fluorine. Hence, assume that sulfur is the central atom.
So now, put sulfur in the center and fluorines on either side. And draw the rough skeleton structure for the Lewis structure of SF2 something like this:
Also read: How to draw Lewis structure of N3– (5 steps)
#2 Show chemical bond
Place two electrons between the atoms to show a chemical bond. Since sulfur is surrounded by two fluorines, use four electrons to show two chemical bonds as follows:
Also read: How to draw Lewis structure of Cl2 (4 steps)
#3 Mark lone pairs
As calculated earlier, we have a total of 20 valence electrons. And in the above structure, we have already used four valence electrons. Hence, sixteen valence electrons are remaining.
Two valence electrons represent one lone pair. So sixteen valence electrons = eight lone pairs.
Note that sulfur is a period 3 element, so it can keep more than 8 electrons in its last shell. And fluorine is a period 2 element, so it can not keep more than 8 electrons in its last shell.
Also, make sure that you start marking these lone pairs on outside atoms first. And then, on the central atom.
The outside atoms are fluorines, so each fluorine will get three lone pairs. And the central atom (sulfur) will get two lone pairs.
So the Lewis structure of SF2 looks something like this:
In the above structure, you can see that the octet is completed on the central atom (sulfur), and also on the outside atoms. Therefore, the octet rule is satisfied.
After completing the octet, one last thing we need to do is, calculate the formal charge and check the stability of the above structure.
Also read: How to draw Lewis structure of COCl2 (5 steps)
#4 Calculate formal charge and check stability
The following formula is used to calculate the formal charges on atoms:
Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons
Collect the data from the above structure and then, write it down below as follows:
- For sulfur atom
Valence electrons = 6
Nonbonding electrons = 4
Bonding electrons = 4
Formal charge = 6 – 4 – ½ (4) = 0
- For each fluorine atom
Valence electrons = 7
Nonbonding electrons = 6
Bonding electrons = 2
Formal charge = 7 – 6 – ½ (2) = 0
Mention the formal charges of atoms on the structure. So the Lewis structure of SF2 looks something like this:
In the above structure, you can see that the formal charges of both (sulfur and fluorine) are zero. Therefore, this is the stable Lewis structure of SF2.
And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.
Related
- Lewis structure of N3–
- Lewis structure of Cl2
- Lewis structure of COCl2
- Lewis structure of BH3
- Lewis structure of NCl3
External links
- Sf2 Molecular Geometry, Lewis Structure, Polarity and Bond Angles – Geometry of Molecules
- SF2 Lewis structure, Molecular geometry, Hybridization, Polar or nonpolar – Topblogtenz
- SF2 Lewis Structure in 6 Steps (With Images) – Pediabay
- SF2 Lewis Structure & Molecular Geometry| Simple Steps – What’s Insight
- SF2 Lewis Structure, Molecular Geometry, Hybridization, Polarity, and MO Diagram – Techiescientist
- How to draw SF2 Lewis Structure? – Science Education and Tutorials
- Chemical Bonding: SF2 Lewis Structure – The Geoexchange
- Draw Lewis formulas for sulfur difluoride (SF2) and sulfur hexafluoride (SF6). Is either one an exception to the octet rule? – Homework.Study.com
- SF2 Lewis Structure (Sulfur Difluoride) – Pinterest
- Draw the Lewis structure for SF2 – Chegg
- Draw the Lewis structure of SF2, showing all lone pairs. Identify the molecular geometry of SF2 – Brainly
- What is the bond angle of SF2? How do you find the angle? – Quora
- Construct the Lewis structure model for the covalent compound sulfur difluoride (SF2) – Numerade
- In the molecule, SF2, what is the correct steric number for sulfur and what is the molecular geometry for the molecule? – Wyzant
Deep
Rootmemory.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.