Lewis Structure of OCl2 (With 6 Simple Steps to Draw!)

I’m super excited to teach you the lewis structure of OCl2 in just 6 simple steps.

Infact, I’ve also given the step-by-step images for drawing the lewis dot structure of OCl2 molecule.

So, if you are ready to go with these 6 simple steps, then let’s dive right into it!

Lewis structure of OCl2 contains two single bonds between the Oxygen (O) atom and each Chlorine (Cl) atom. The Oxygen atom (O) is at the center and it is surrounded by 2 Chlorine atoms (Cl). The Oxygen atom has 2 lone pairs and both the Chlorine atoms have 3 lone pairs.

Let’s draw and understand this lewis dot structure step by step.

(Note: Take a pen and paper with you and try to draw this lewis structure along with me. I am sure you will definitely learn how to draw lewis structure of OCl2).

6 Steps to Draw the Lewis Structure of OCl2

Step #1: Calculate the total number of valence electrons

Here, the given molecule is OCl2 (oxygen dichloride). In order to draw the lewis structure of OCl2, first of all you have to find the total number of valence electrons present in the OCl2 molecule.
(Valence electrons are the number of electrons present in the outermost shell of an atom).

So, let’s calculate this first.

Calculation of valence electrons in OCl2

• For Oxygen:

Oxygen is a group 16 element on the periodic table. ^[1]

Hence, the valence electron present in oxygen is 6 (see below image).

• For Chlorine:

Chlorine is a group 17 element on the periodic table. ^[2]

Hence, the valence electron present in chlorine is 7 (see below image).

Hence in a OCl2 molecule, 

Valence electrons given by Oxygen (O) atom = 6
Valence electrons given by each Chlorine (Cl) atom = 7
So, total number of Valence electrons in OCl2 molecule = 6 + 7(2) = 20

Step #2: Select the center atom

While selecting the atom, always put the least electronegative atom at the center. 

(Remember: Fluorine is the most electronegative element on the periodic table and the electronegativity decreases as we move right to left in the periodic table as well as top to bottom in the periodic table). ^[3]

Here in the OCl2 molecule, if we compare the oxygen atom (O) and chlorine atom (Cl), then the oxygen is less electronegative than chlorine.

So, oxygen should be placed in the center and the remaining 2 chlorine atoms will surround it.

Step #3: Put two electrons between the atoms to represent a chemical bond

Now in the above sketch of OCl2 molecule, put the two electrons (i.e electron pair) between each oxygen atom and chlorine atom to represent a chemical bond between them.

These pairs of electrons present between the Oxygen (O) and Chlorine (Cl) atoms form a chemical bond, which bonds the oxygen and chlorine atoms with each other in a OCl2 molecule.

Step #4: Complete the octet (or duplet) on outside atoms. If the valence electrons are left, then put the valence electrons pair on the central atom

Don’t worry, I’ll explain!

In the Lewis structure of OCl2, the outer atoms are chlorine atoms.

So now, you have to complete the octet on these chlorine atoms (because chlorine requires 8 electrons to have a complete outer shell).

Now, you can see in the above image that all the chlorine atoms form an octet.

Also, only 16 valence electrons of OCl2 molecule are used in the above structure.

But there are total 20 valence electrons in OCl2 molecule (as calculated in step #1).

So the number of electrons left to be kept on the central atom = 20 – 16 = 4.

So let’s keep these four electrons (i.e 2 electron pairs) on the central atom.

Now, let’s move to the next step.

Step #5: Check whether the central atom has octet or not. If it does not have an octet, then move the electron pair from the outer atom to form a double bond or triple bond

In this step, we have to check whether the central atom (i.e oxygen) has an octet or not. 

In simple words, we have to check whether the central Oxygen (O) atom is having 8 electrons or not.

As you can see from the above image, the central atom (i.e oxygen), has 8 electrons. So it fulfills the octet rule and the oxygen atom is stable.

Step #6: Final step – Check the stability of lewis structure by calculating the formal charge on each atom

Now, you have come to the final step and here you have to check the formal charge on oxygen atom (O) as well as each chlorine atom (Cl).

For that, you need to remember the formula of formal charge;

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

• For Oxygen:
  Valence electron = 6 (as it is in group 16)
  Nonbonding electrons = 4
  Bonding electrons = 4
• For Chlorine:
  Valence electron = 7 (as it is in group 17)
  Nonbonding electrons = 6
  Bonding electrons = 2

Formal charge	=	Valence electrons	–	Nonbonding electrons	–	(Bonding electrons)/2
O	=	6	–	4	–	4/2	=	0
Cl	=	7	–	6	–	2/2	=	0

So you can see above that the formal charges on oxygen as well as chlorine are “zero”.

Hence, there will not be any change in the above structure and the above lewis structure of OCl2 is the final stable structure only.

Each electron pair (:) in the lewis dot structure of OCl2 represents the single bond ( | ). So the above lewis dot structure of OCl2 can also be represented as shown below.

Related lewis structures for your practice:
Lewis structure of CH3COOH
Lewis structure of SiCl4
Lewis structure of BrO3-
Lewis structure of CBr4
Lewis structure of OCN-

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