Lewis structure of Cl2O

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The Lewis structure of Cl₂O contains two single bonds, with oxygen in the center, and two chlorines on either side. There are three lone pairs on each chlorine atom, and two lone pairs on the oxygen atom.

Steps

By using the following steps, you can easily draw the Lewis structure of Cl₂O:

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

Now Cl₂O has two chlorine atoms and one oxygen atom.

So the total number of valence electrons = (valence electrons of chlorine atom × 2) + valence electrons of oxygen atom

Therefore, the total number of valence electrons = 14 + 6 = 20

• 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 chlorine and oxygen as follows:

Electronegativity value of chlorine = 3.16
Electronegativity value of oxygen = 3.44

Obviously, chlorine is less electronegative than oxygen. But if we assume chlorine as the central atom, then we do not get the formal charges on atoms closer to zero.

Hence, assume that oxygen is the central atom.

So now, put oxygen in the center and chlorines on either side. And draw the rough skeleton structure for the Lewis structure of Cl₂O something like this:

Also read: How to draw Lewis structure of ClO₄^– (5 steps)

#2 Show chemical bond

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

Also read: How to draw Lewis structure of CBr₄ (4 steps)

#3 Mark lone pairs

As calculated earlier, we have a total of 20 valence electrons. And in the above structure, we have already used four valence electrons. Hence, sixteen valence electrons are remaining.

Two valence electrons represent one lone pair. So sixteen valence electrons = eight lone pairs.

Note that chlorine is a period 3 element, so it can keep more than 8 electrons in its last shell. And oxygen is a period 2 element, so it can not 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 (oxygen) will get two lone pairs.

So the Lewis structure of Cl₂O looks something like this:

In the above structure, you can see that the octet is completed on the central atom (oxygen), 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 SeO₂ (6 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 each chlorine atom

Valence electrons = 7
Nonbonding electrons = 6
Bonding electrons = 2

Formal charge = 7 – 6 – ½ (2) = 0

• For oxygen atom

Valence electrons = 6
Nonbonding electrons = 4
Bonding electrons = 4

Formal charge = 6 – 4 – ½ (4) = 0

Mention the formal charges of atoms on the structure. So the Lewis structure of Cl₂O looks something like this:

In the above structure, you can see that the formal charges of both (chlorine and oxygen) are zero. Therefore, this is the stable Lewis structure of Cl₂O.

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

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Related

• Lewis structure of ClO₄^–
• Lewis structure of CBr₄
• Lewis structure of SeO₂
• Lewis structure of ICl₄^–
• Lewis structure of SiCl₄

External video

• Cl2O Lewis Structure: How to Draw the Lewis Structure for Cl2O (Dichlorine Monoxide) – YouTube • Wayne Breslyn

External links

• How to Draw the Dot Structure for Cl2O – The Geoexchange
• Cl2O (Dichlorine monoxide) Lewis Structure and Steps of Drawing – Chemistry School
• Calculate the formal charges on all the atoms in the following two Lewis structures for the same molecule, Cl2O – Homework.Study.com
• what is the lewis dot structure of Cl2O – Chegg
• What is the Lewis structure of Cl2O and its molecular geometry? – Answers
• Why is O the central atom of Cl2O but nitrogen the center of N2O? – Quora
• Cl2O (Dichlorine Monoxide) Oxidation Number – ChemicalAid
• Draw the Lewis structure of Cl2O, add non-zero formal charges to atoms – Numerade