Lewis structure of SeCl4

The information on this page is ✔ fact-checked.

The Lewis structure of SeCl₄ contains four single bonds, with selenium in the center, and four chlorines on either side. There are three lone pairs on each chlorine atom, and one lone pair on the selenium atom.

Steps

By using the following steps, you can easily draw the Lewis structure of SeCl₄.

#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… selenium is a group 16 element and chlorine is a group 17 element. Hence, selenium has six valence electrons and chlorine has seven valence electrons.

Now SeCl₄ has one selenium atom and four chlorine atoms.

So the total number of valence electrons = valence electrons of selenium 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 selenium and chlorine as follows:

Electronegativity value of selenium = 2.55
Electronegativity value of chlorine = 3.16

Obviously, selenium is less electronegative than chlorine. Hence, assume that selenium is the central atom.

So now, put selenium in the center and chlorines on either side. And draw the rough skeleton structure for the Lewis structure of SeCl₄ something like this:

Also read: How to draw Lewis structure of SeS₂ (6 steps)

#2 Show chemical bond

Place two electrons between the atoms to show a chemical bond. Since selenium is surrounded by four chlorines, use eight electrons to show four chemical bonds as follows:

Also read: How to draw Lewis structure of TeCl₄ (4 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 selenium is a period 4 element, so it can keep more than 8 electrons in its last shell. And chlorine is a period 3 element, so it can 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 chlorines, so each chlorine will get three lone pairs. And the central atom (selenium) will get one lone pair.

So the Lewis structure of SeCl₄ looks something like this:

In the above structure, you can see that the octet is completed on the central atom (selenium), 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 C₂Br₂ (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 selenium 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 SeCl₄ looks something like this:

In the above structure, you can see that the formal charges of both (selenium and chlorine) are zero. Therefore, this is the stable Lewis structure of SeCl₄.

And each horizontal line drawn in the above structure represents a pair of bonding valence electrons.

📝 Your feedback matters. Visit our contact page.

Related

• Lewis structure of SeS₂
• Lewis structure of TeCl₄
• Lewis structure of C₂Br₂
• Lewis structure of BrO₄^–
• Lewis structure of HOCN

External video

• SeCl4 Lewis Structure: How to Draw the Lewis Structure for SeCl4 – Wayne Breslyn

External links

• SeCl4 Lewis Structure, Geometry, Hybridization, and Polarity – Techiescientist
• SeCl4 Lewis Structure in 5 Steps (With Images) – Pediabay
• Draw the Lewis structure for SeCl4 – Homework.Study.com
• Draw the Lewis structure and predict the molecular geometry of SeCl4 – Chegg
• Draw the Lewis Structure of SeCl4 – Bartleby
• Draw the most stable Lewis Dot Structure of SeCl4 with any resonance structures if applicable – Course Hero
• Selenium tetrachloride – Wikipedia
• Selenium tetrachloride | SeCl4 | CID 66205 – National Institutes of Health (.gov)