Lewis structure of ClO2-

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The Lewis structure of ClO₂^– contains one double bond and one single bond, with chlorine in the center, and two oxygens on either side. The left oxygen atom has two lone pairs, the right oxygen atom has three lone pairs, and the chlorine atom also has two lone pairs.

Plus, there is a negative (-1) charge on the right oxygen atom.

Steps

By using the following steps, you can easily draw the Lewis structure of ClO₂^–:

#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)
#5 Convert lone pair and calculate formal charge again (if formal charges are not closer to zero)

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 ClO₂^– has one chlorine atom and two oxygen atoms.

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

And ClO₂^– has a negative (-1) charge, so we have to add one more electron.

Therefore, the total number of valence electrons = 7 + 12 + 1 = 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. Hence, assume that chlorine is the central atom.

So now, put chlorine in the center and oxygens on either side. And draw the rough skeleton structure for the Lewis structure of ClO₂^– something like this:

Also read: How to draw Lewis structure of H₂O₂ (4 steps)

#2 Show chemical bond

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

#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 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 oxygens, so each oxygen will get three lone pairs. And the central atom (chlorine) will get two lone pairs.

So the Lewis structure of ClO₂^– looks something like this:

In the above structure, you can see that the octet is completed on the central atom (chlorine), and also on the outside atoms. Therefore, the octet rule is satisfied.

Now calculate the formal charge and check the stability of the above structure.

Also read: How to draw Lewis structure of ClO₃^– (5 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 chlorine atom

Valence electrons = 7
Nonbonding electrons = 4
Bonding electrons = 4

Formal charge = 7 – 4 – ½ (4) = +1

• For each oxygen atom

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

Formal charge = 6 – 6 – ½ (2) = -1

Mention the formal charges of atoms on the structure. So the Lewis structure of ClO₂^– looks something like this:

In the above structure, you can see that the formal charges of atoms are not closer to zero. Therefore, convert lone pair and calculate formal charge again.

Also read: How to draw Lewis structure of CH₂Cl₂ (4 steps)

#5 Convert lone pair and calculate formal charge again

As mentioned earlier, chlorine is a period 3 element, so it can keep more than 8 electrons in its last shell.

So convert one lone pair from one oxygen atom to make a new bond with the chlorine atom. And then, the Lewis structure of ClO₂^– looks something like this:

Now one last thing we need to do is, calculate the formal charge again and check the stability of the above structure.

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 chlorine atom

Valence electrons = 7
Nonbonding electrons = 4
Bonding electrons = 6

Formal charge = 7 – 4 – ½ (6) = 0

• For left oxygen atom

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

Formal charge = 6 – 4 – ½ (4) = 0

• For right oxygen atom

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

Formal charge = 6 – 6 – ½ (2) = -1

Mention the formal charges of atoms on the structure. So the Lewis structure of ClO₂^– looks something like this:

In the above structure, you can see that the formal charges of atoms are closer to zero. Therefore, this is the most stable Lewis structure of ClO₂^–.

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

Now ClO₂^– is an ion having a negative (-1) charge, so draw brackets around the above Lewis structure and mention that charge on the top right corner. And then, the Lewis structure of ClO₂^– looks something like this:

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Related

• Lewis structure of H₂O₂
• Lewis structure of ClO₃^–
• Lewis structure of CH₂Cl₂
• Lewis structure of PCl₅
• Lewis structure of C₂H₆

External video

• ClO2- Lewis Structure – How to Draw the Lewis Structure for ClO2- (Chlorite Ion) – Wayne Breslyn

External links

• Drawing the Lewis Structure for ClO2 – The University of Maryland
• ClO2- lewis structure, molecular geometry, polarity, hybridization, angle – Topblogtenz
• ClO2- Lewis Structure, Geometry, Hybridization, and Polarity – Techiescientist
• How can I draw the Lewis structure for ClO2-? – Socratic
• ClO2- Lewis structure, characteristics: 11 Facts you should know – Lambda Geeks
• ClO2- lewis structure – Laurence Lavelle
• Lewis Dot of the Chlorite Ion ClO2- – Kent’s Chemistry
• Chemical Bonding: ClO2- Lewis Structure – The Geoexchange
• ClO2- lewis structure, molecular geometry, hybridization – Pinterest
• ClO2- Lewis Structure in 6 Steps (With Images) – Pediabay
• Lewis structure of clo2- – Reddit
• How to Draw the Lewis Structure for ClO2- (Chlorite Ion) – BitChute
• In the Lewis structure of ClO2- in which all atoms obey the octet rule, what is the formal charge on Cl? – Quora
• ClO2 (Chlorite Ion) Oxidation Number – ChemicalAid
• draw a lewis structure for clo2- – Brainly
• Draw the Lewis structure of the chlorite ion, ClO2- which is used as a bleaching agent – Numerade
• Draw the Lewis structure for ClO2- – Chegg
• What is the Lewis formula for the octet rule for the ions ClO2? – Answers
• How many valence electrons does ClO2- get in its Lewis Dot diagram? – Bartleby