SO2Cl2 Lewis Structure in 5 Steps (With Images)

So you have seen the above image by now, right?

Let me explain the above image in short.

SO2Cl2 lewis structure has a Sulfur atom (S) at the center which is surrounded by two Oxygen atoms (O) and two Chlorine atoms (Cl). There are single bonds between the Sulfur & Chlorine atoms and double bonds between the Sulfur & Oxygen atoms. There are 2 lone pairs on Oxygen atoms (O) and 3 lone pairs on Chlorine atoms (Cl).

If you haven’t understood anything from the above image of SO2Cl2 lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of SO2Cl2 molecule.

So let’s move to the steps of drawing the lewis structure of SO2Cl2.

Steps of drawing SO2Cl2 lewis structure

Step 1: Find the total valence electrons in SO2Cl2 molecule

In order to find the total valence electrons in SO2Cl2 molecule, first of all you should know the valence electrons present in sulfur atom, oxygen atom as well as chlorine atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)

Here, I’ll tell you how you can easily find the valence electrons of sulfur, oxygen as well as chlorine using a periodic table.

Total valence electrons in SO2Cl2 molecule

→ Valence electrons given by sulfur atom:

Sulfur is a group 16 element on the periodic table. ^[1] Hence the valence electrons present in sulfur is 6.

You can see the 6 valence electrons present in the sulfur atom as shown in the above image.

→ Valence electrons given by oxygen atom:

Oxygen is group 16 element on the periodic table. ^[2] Hence the valence electrons present in oxygen is 6.

You can see the 6 valence electrons present in the oxygen atom as shown in the above image.

→ Valence electrons given by chlorine atom:

Chlorine is group 17 element on the periodic table. ^[3] Hence the valence electrons present in chlorine is 7.

You can see the 7 valence electrons present in the chlorine atom as shown in the above image.

Hence, 

Total valence electrons in SO2Cl2 molecule = valence electrons given by 1 sulfur atom + valence electrons given by 2 oxygen atoms + valence electrons given by 2 chlorine atoms = 6 + 6(2) + 7(2) = 32.

Step 2: Select the central atom

For selecting the center atom, you have to remember that the atom which is less electronegative remains at the center.

Now here the given molecule is SO2Cl2 and it contains sulfur atom (S), oxygen atoms (O) and chlorine atoms (Cl).

You can see the electronegativity values of sulfur atom (S), oxygen atom (O) and chlorine atom (Cl) in the above periodic table.

If we compare the electronegativity values of sulfur (S), oxygen (O) and chlorine (Cl) then the sulfur atom is less electronegative.

So here the sulfur atom (S) is the center atom and the oxygen atoms (O) & chlorine atoms (Cl) are the outside atoms.

Step 3: Connect each atoms by putting an electron pair between them

Now in the SO2Cl2 molecule, you have to put the electron pairs between the sulfur-oxygen atoms and sulfur-chlorine atoms.

This indicates that these atoms are chemically bonded with each other in a SO2Cl2 molecule.

Step 4: Make the outer atoms stable

Now in this step, you have to check the stability of the outer atoms.

Here in the sketch of SO2Cl2 molecule, you can see that the outer atoms are oxygen atoms (O) and chlorine atoms (Cl).

These outer oxygen atoms and chlorine atoms are forming an octet and hence they are stable.

Also, in step 1 we have calculated the total number of valence electrons present in the SO2Cl2 molecule.

The SO2Cl2 molecule has a total 32 valence electrons and all these valence electrons are used in the above sketch.

Hence there are no remaining electron pairs to be kept on the central atom. 

So now let’s proceed to the next step.

Step 5: Check the stability of lewis structure

Now you have come to the final step in which you have to check the stability of lewis structure of SO2Cl2 molecule.

The stability of lewis structure can be checked by using a concept of formal charge.

In short, now you have to find the formal charge on sulfur (S) atom, oxygen (O) atoms as well as chlorine (Cl) atoms present in the SO2Cl2 molecule.

For calculating the formal charge, you have to use the following formula;

Formal charge = Valence electrons – (Bonding electrons)/2 – Nonbonding electrons

You can see the number of bonding electrons and nonbonding electrons for each atom of SO2Cl2 molecule in the image given below.

For Sulfur (S) atom:
Valence electrons = 6 (because sulfur is in group 16)
Bonding electrons = 8
Nonbonding electrons = 0

For Oxygen (O) atom:
Valence electrons = 6 (because oxygen is in group 16)
Bonding electrons = 2
Nonbonding electrons = 6

For Chlorine (Cl) atom:
Valence electrons = 7 (because chlorine is in group 17)
Bonding electrons = 2
Nonbonding electrons = 6

Formal charge	=	Valence electrons	–	(Bonding electrons)/2	–	Nonbonding electrons
S	=	6	–	8/2	–	0	=	+2
O	=	6	–	2/2	–	6	=	-1
Cl	=	7	–	2/2	–	6	=	0

From the above calculations of formal charge, you can see that the sulfur (S) atom has +2 charge while the two oxygen atoms have -1 charge.

So let’s keep these charges on the respective atoms of the SO2Cl2 molecule.

The above image shows that the lewis structure of SO2Cl2 is not stable.

So we have to minimize these charges by shifting the electron pair from the oxygen atom to the sulfur atom.

After shifting the electron pair from the oxygen atoms to the sulfur atom, the charges on sulfur and two oxygen atoms become zero. And this is a more stable lewis structure. (see below image).

In the above lewis dot structure of SO2Cl2, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of SO2Cl2.

I hope you have completely understood all the above steps.

For more practice and better understanding, you can try other lewis structures listed below.

Try (or at least See) these lewis structures for better understanding:

C2H3Cl Lewis Structure	CH2Br2 Lewis Structure
SiBr4 Lewis Structure	SeO3 Lewis Structure
CHF3 Lewis Structure	BrO4- Lewis Structure