SCl4 Lewis structure

SCl₄ (sulfur tetrachloride) has one sulfur atom and four chlorine atoms.

In the SCl₄ Lewis structure, there are three single bonds around the sulfur atom, with three chlorine atoms attached to it. Each chlorine atom has three lone pairs, and the sulfur atom has one lone pair.

Alternative method: Lewis structure of SCl₄

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, sulfur lies in group 16, and chlorine lies in group 17.

Hence, sulfur has six valence electrons and chlorine has seven valence electrons.

Since SCl₄ has one sulfur atom and four chlorine atoms, so…

Valence electrons of one sulfur atom = 6 × 1 = 6
Valence electrons of four chlorine atoms = 7 × 4 = 28

And the total valence electrons = 6 + 28 = 34

Learn how to find: Sulfur valence electrons and Chlorine valence electrons

• Second, find the total electron pairs

We have a total of 34 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 34 ÷ 2 = 17

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since sulfur is less electronegative than chlorine, assume that the central atom is sulfur.

Therefore, place sulfur in the center and chlorines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 17 electron pairs. And four S — Cl bonds are already marked. So we have to only mark the remaining thirteen electron pairs as lone pairs on the sketch.

Also remember that both (sulfur and chlorine) are the period 3 elements, so they can keep more than 8 electrons in their last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are chlorines.

So for each chlorine, there are three lone pairs, and for sulfur, there is one lone pair.

Mark the lone pairs on the sketch as follows:

Formal charge

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For sulfur atom, formal charge = 6 – 2 – ½ (8) = 0

For each chlorine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, both sulfur and chlorine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of SCl₄ includes a central sulfur atom linked to four chlorine atoms through single covalent bonds. In this arrangement, the sulfur atom utilizes an expanded valence shell to accommodate ten electrons, which consist of four bonding pairs and one lone pair. Within this layout, each chlorine atom successfully satisfies the octet rule by retaining three lone pairs alongside its single shared bond. This configuration represents the most stable state for the molecule because it results in a formal charge of zero for every atom involved. Thus, this specific electronic distribution serves as the definitive and most accurate Lewis representation of sulfur tetrachloride.

Next: SO₂Cl₂ Lewis structure

External video

• SCl4 Lewis Structure: How to Draw the Lewis Structure for Sulfur Tetrachloride – YouTube • Wayne Breslyn

External links

• https://www.chemistryscl.com/general/SCl4-lewis-structure/
• https://topblogtenz.com/scl4-lewis-structure-molecular-geometry-polar-or-nonpolar/
• https://lambdageeks.com/scl4-lewis-structure/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/SCl4-lewis-structure.html
• https://sciedutut.com/scl4-lewis-structure/