Lewis structure of SiCl4

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The Lewis structure of SiCl₄ contains four single bonds, with silicon in the center, and four chlorines on either side. There are three lone pairs on each chlorine atom, and the silicon atom does not have any lone pair.

Steps

By using the following steps, you can easily draw the Lewis structure of SiCl₄:

#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… silicon is a group 14 element and chlorine is a group 17 element. Hence, silicon has four valence electrons and chlorine has seven valence electrons.

Now SiCl₄ has one silicon atom and four chlorine atoms.

So the total number of valence electrons = valence electrons of silicon atom + (valence electrons of chlorine atom × 4)

Therefore, the total number of valence electrons = 4 + 28 = 32

• 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 silicon and chlorine as follows:

Electronegativity value of silicon = 1.90
Electronegativity value of chlorine = 3.16

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

So now, put silicon in the center and chlorines on either side. And draw the rough skeleton structure for the Lewis structure of SiCl₄ something like this:

Also read: How to draw Lewis structure of SiF₄ (4 steps)

#2 Show chemical bond

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

Also read: How to draw Lewis structure of OCN^– (5 steps)

#3 Mark lone pairs

As calculated earlier, we have a total of 32 valence electrons. And in the above structure, we have already used eight valence electrons. Hence, twenty-four valence electrons are remaining.

Two valence electrons represent one lone pair. So twenty-four valence electrons = twelve lone pairs.

Note that both (silicon 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 (silicon) will not get any lone pair, because all twelve lone pairs are used.

So the Lewis structure of SiCl₄ looks something like this:

In the above structure, you can see that the octet is completed on the central atom (silicon), 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 CH₃F (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 silicon atom

Valence electrons = 4
Nonbonding electrons = 0
Bonding electrons = 8

Formal charge = 4 – 0 – 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 SiCl₄ looks something like this:

In the above structure, you can see that the formal charges of both (silicon and chlorine) are zero. Therefore, this is the stable Lewis structure of SiCl₄.

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

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Related

• Lewis structure of SiF₄
• Lewis structure of OCN^–
• Lewis structure of CH₃F
• Lewis structure of BrO₃^–
• Lewis structure of NH₄⁺

External video

• SiCl4 Lewis Structure – How to Draw the Lewis Structure for SiCl4 – YouTube • Wayne Breslyn

External links

• Silicon Tetrachloride (SiCl4) Lewis Structure and Steps of Drawing – Chemistry School
• Chemical Bonding: SiCl4 Lewis Structure – The Geoexchange
• SiCl4 Lewis Structure in 6 Steps (With Images) – Pediabay
• SiCl4 Lewis structure, Molecular geometry, Bond angle, Polarity, Electrons – Topblogtenz
• SiCl4 Lewis Structure (Silicon Tetrachloride) – Pinterest
• Draw the Lewis structure for SiCl4. How many bonds are around the central atom, and what is the shape of this molecule? – Homework.Study.com
• Draw the Lewis structure of SiCl4. Include all the lone pairs – Chegg
• What is the lewis structure for silicon tetrachloride, SiCl4? – Brainly
• How to draw a SiCl4 Lewis Structure? – Science Education and Tutorials
• SiCl4 Geometry and Hybridization – Chemistry Steps
• Is SiCl4 square planar or tetrahedral? – Socratic
• SiCl4 Polar or Nonpolar| Easy Explanation – What’s Insight
• Is SiCl4 polar or non polar? – Quora