The Lewis structure of SCl4 contains four single bonds, with sulfur in the center, and four chlorines on either side. There are three lone pairs on each chlorine atom, and one lone pair on the sulfur atom.
Steps
By using the following steps, you can easily draw the Lewis structure of SCl4.
#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 chlorine is a group 17 element. Hence, sulfur has six valence electrons and chlorine has seven valence electrons.
Now SCl4 has one sulfur atom and four chlorine atoms.
So the total number of valence electrons = valence electrons of sulfur atom + (valence electrons of chlorine atom × 4)
Therefore, the total number of valence electrons = 6 + 28 = 34
- 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 chlorine as follows:
Electronegativity value of sulfur = 2.58
Electronegativity value of chlorine = 3.16
Obviously, sulfur is less electronegative than chlorine. Hence, assume that sulfur is the central atom.
So now, put sulfur in the center and chlorines on either side. And draw the rough skeleton structure for the Lewis structure of SCl4 something like this:
Also read: How to draw Lewis structure of SeO3 (6 steps)
#2 Show chemical bond
Place two electrons between the atoms to show a chemical bond. Since sulfur is surrounded by four chlorines, use eight electrons to show four chemical bonds as follows:
Also read: How to draw Lewis structure of H2SO3 (5 steps)
#3 Mark lone pairs
As calculated earlier, we have a total of 34 valence electrons. And in the above structure, we have already used eight valence electrons. Hence, twenty-six valence electrons are remaining.
Two valence electrons represent one lone pair. So twenty-six valence electrons = thirteen lone pairs.
Note that both (sulfur and chlorine) are the period 3 elements, so they can keep more than 8 electrons in their 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 chlorines, so each chlorine will get three lone pairs. And the central atom (sulfur) will get one lone pair.
So the Lewis structure of SCl4 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 CCl2F2 (4 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 = 2
Bonding electrons = 8
Formal charge = 6 – 2 – ½ (8) = 0
- For each chlorine 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 SCl4 looks something like this:
In the above structure, you can see that the formal charges of both (sulfur and chlorine) are zero. Therefore, this is the stable Lewis structure of SCl4.
And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.
Related
- Lewis structure of SeO3
- Lewis structure of H2SO3
- Lewis structure of CCl2F2
- Lewis structure of HSO4–
- Lewis structure of C2H2Cl2
External links
- Sulfur tetrachloride (SCl4) Lewis Structure – Chemistry School
- Drawing the Lewis Structure for SCl4 – The Geoexchange
- SCl4 Lewis Structure in 5 Steps (With Images) – Pediabay
- SCl4 lewis structure, Molecular geometry, Polar or nonpolar, Hybridization – Topblogtenz
- How can I determined the Lewis structure for SCl4? – Quora
- How to draw SCl4 Lewis Structure? – Science Education and Tutorials
- What are the Lewis structure and molecular geometry for SCl4? – Pearson
- Draw the Lewis structure of SCl4 – Chegg
- SCl4 (Sulfur Tetrachloride) Oxidation Number – ChemicalAid
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.