Chlorine (Cl2) lewis dot structure, molecular geometry, polar or non-polar, hybridization

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Chlorine gas exists as a diatomic molecule that belongs to the halogen group with the chemical formula Cl2. It is green in color gas and corrosive in nature. It is mainly used for the manufacture of paper and clothes.

In this article, we will study Chlorine gas (Cl2) lewis dot structure, its molecular geometry, is it polar or non-polar, hybridization, etc.

Chlorine gas is very reactive thus they bonded to each other to stabilize the molecule. It appears as yellow-green gas at room temperature and pressure. It can adversely affect the throat, eye, and respiration system if exposed for a long time to the human body.

Properties of Chlorine

  • It is heavier than air and strong irritating odor.
  • It is slightly soluble in water.
  • Chlorine belongs to the 17th group and halogen family in the periodic table.
  • It has high electronegativity and non-metallic behavior.
  • Chlorine has a boiling point of -34.04 °C and a melting point of −101.5 °C.
  • It has a molar mass of 70.9 g/mol.
Name of MoleculeChlorine gas or dichlorine
Chemical formulaCl2
Molecular geometry of Cl2Linear
Electron geometry of Cl2Linear
HybridizationSp³
Bond typeCovalent
Total Valence electron for Cl214
The formal charge of Cl20

How to draw Cl2 lewis structure or electron dot structure

Cl2 lewis’s structure has two chlorine atoms connected with a single bond with 3 lone pairs on each chlorine. It is very simple and straightforward to draw than most of the molecules.

As Cl2 is the diatomic molecule that has only two atoms so it doesn’t require all steps for making the lewis diagram as we need for other molecules like SCl2, CHCl3, NCl3, etc.

To draw the Cl2 lewis dot structure we will follow some common steps of the lewis diagram in a simple way.

Follow steps for drawing the lewis dot structure of Cl2

  1. Count the total number of the valence electron
  2. Find the least electronegative atom and placed it at center
  3. Connect outer atom to central atom with a single bond
  4. Place remaining valence electron starting from outer atom first
  5. Complete central atom octet and make covalent bond if necessary

1. Count total valence electron in Cl2

For making any lewis diagram our first step is to determine how many valence electron a molecule contain. So, we have to find how many valence electrons available for drawing the Cl2 lewis structure. For this just look at the periodic group of Chlorine in the periodic table.

As chlorine belongs to the halogen group which is the 17th group in the periodic table. So, the valence electron for chlorine in its outermost shell is 7.

⇒ Total valence electron in Chlorine = 7

∴ Total valence electron available for Cl2 lewis dot structure = 7*2 = 14 electrons     [∴Two chlorine atom each has 7 valence electron in its outermost shell]

Total valence electron available for Cl2 lewis structure

2. Find the least electronegative atom and placed it at center

For Cl2 lewis’s structure, only two atoms present which are similar. So, it doesn’t matter which atom is less or more electronegative. Just put one chlorine atom at whatever place you like and another one next to it.

3. Connect outer atom to central atom with a single bond

Generally in this step, we connect all outer atoms to the central atom with the help of a single bond for drawing the lewis diagram of any molecule.

In the case of Cl2, this process is straightforward. Simply put one single bond in between two chlorine atoms.

connect two chlorine atom with single bond

Now count how many valence electrons we used till now. As one single bond has two electrons and in the above structure, we used only one single bond in between two chlorine atoms.

Therefore, we used 2 electrons from the total of 14 valence electrons available for drawing the lewis structure of Cl2.

(14 – 2) = 12 valence electron

Now we are left with 12 valence electrons more.

4. Place remaining valence electrons starting from outer atom first

As Cl2 lewis’s structure only contain two atoms that are similar so you can assume any of one is central and the other one is the outer atom. But it doesn’t matter, start placing the remaining electron around any chlorine atom as you prefer.

We have 12 remaining valence electrons and each chlorine needs 8 electrons for completing its octet. But each chlorine already sharing two electrons with the help of a single bond. So, both of them only need 6 electrons to complete their octet.

Cl2 lewis dot structure(Chlorine gas)

Lewis dot structure for Cl2 (Chlorine gas)

By looking at the above Cl2 lewis structure, we see both chlorine atoms completed their octet comfortably as both of them have 8 electrons around them.

And no need to make any covalent bond in this lewis diagram because we got our stable lewis dot structure for Cl2.

What are the electron and molecular geometry of Cl2

The molecular geometry of Cl2 is linear as all diatomic molecules in chemistry have linear geometry because diatomic molecules contain two atoms that are connected with a single bond that produces only a straight line geometry. So, any other geometry is not possible for this type of molecule.

Linear geometry is the simplest arrangement of atoms in a straight line. The electron geometry for Cl2 is also linear. Just remember all diatomic molecule or any molecule that have only two atoms, there geometry or shape will be linear. That’s it.

Some easy steps to determine the geometry of any molecule.

  1. Draw the Lewis structure of the given molecule.
  2. Count how many lone pair and bonded pair electrons it contains.
  3. Use VSEPR theory or chart to determine the geometry of the given molecule.

Here, we need to find the molecular geometry of Cl2. So, follow these given steps to determine its shape or geometry.

As we have already drawn the lewis structure of Cl2, so directly start with step 2.

1. Find the Number of lone pairs and bonded pair electrons in the Cl2 lewis structure

The lone pair is unshared electrons that not involve in any chemical bonding whereas bonded pair electrons just opposite to it, they have shared electrons that involve in chemical bonding.

Lone pair and bonded pair electron present in Cl2 lewis structure

As shown in the figure, the Cl2 lewis structure has 1 bonded pair electron in between two chlorine atoms because they are shareable for making the chemical bond.

And 3 lone pairs on each chlorine atom because they are unshared electrons that are not shareable for any type of chemical bonding.

Note: Only a lone pair on the central atom of the molecule considers for finding the geometry of any molecule.

In Cl2, there is no central atom, so the lone pair considered zero for determining its geometry.

2. Use VSEPR chart to determine the molecular geometry of Cl2

VSEPR chart

According to Valence shell electron pair repulsion theory if the given molecule has no lone pair on the central atom and has only one bonded pair of electrons, then the molecular geometry of that molecule will be linear and electron geometry will also linear.

In the case of Cl2, there is no central atom, so no lone pair on it, and Cl2 has only one bonded pair of electrons that is between two chlorine atoms.

So, the molecular geometry of Cl2 is linear.

Molecular geometry of Cl2 (Chlorine)

 Molecular geometry of Cl2

Hybridization of Cl2

The hybridization of each chlorine atom in the Cl2 lewis structure is Sp³. It means it has one s orbital and three p orbital. And this makes four hybrid orbitals.

In order to find the hybridization of the chlorine atom in the Cl2 molecule, we have to find its steric number.

Steric number = Number of atoms attached + Number of lone pairs on atom

For chlorine, it has three lone pairs on it and one atom attached to it.

= (1 + 3)

= 4 is the steric number of chlorine in Cl2.

So, 4 steric number means, it has Sp³ hybridization.

Steric numberHybridization
1S
2Sp
3Sp²
4Sp³

Dichlorine polarity: is Cl2 polar or nonpolar

The polarity of any molecule depends on its geometry, lone pairs, dipole moment, etc. A molecule is said to be polar when it can dissolve in water. But in theoretical ways, a molecule can be polar when it has some dipole moment that cannot cancel out.

A polar molecule has an unequal charge distributed over an atom. The separation of positive and negative charge lead to dipole moment.

Whereas a non-polar molecule has equal distribution of charge and has some dipole moment that can easily be canceled out. All non-polar molecules have zero dipole moment.

So, Is Cl2 polar or non-polar? I think you already know the answer, Cl2 is non-polar. Generally, all diatomic molecule that has same atoms is non-polar in nature because they don’t have any dipole moment along with the bond.

The dipole moment only generated in a molecule when there are a separation of charge present or unequal charges distributed over atoms.

Let’s dive deep into this to check the polarity of Cl2 with the help of three important factors.

Three factors that indicate the polarity of Cl2 

1. Electronegativity: 

Electronegativity is one of the top factors to check the polarity of any molecule. Higher the electronegativity difference between the bond in molecule more is the polar nature of that molecule.

According to the Pauling scale, if the difference of electronegativity of atoms in bond is less than 0.4, then they considered to the non-polar molecule, and when the electronegativity difference of an atom in the bond between 0.4-0.7 then they considered being a polar molecule. Higher than this, the molecule can be considered to be ionic.

For Cl2, we have two chlorine atoms and they have the same electronegativity. So, the difference in electronegativity between them is zero. Hence it is a non-polar molecule.

2. Dipole moment

The net dipole moment in Cl2 is zero. As there is no separation of charge that can lead to dipole moment in it. Dipole moment ensures the strength of polarity between two atoms. The greater the dipole moment of the molecule, the more is the polar nature of that molecule. 

In the mathematical expression, dipole moment can be defined as “A dipole moment is the product of the magnitude of the charge and the distance between the centers of the positive and negative charges”.

It is denoted by µ and measured in the Debye unit.

⇒ Dipole moment formula =  charge on the atoms * the distance between them 

∴ D = Q × R

3. Geometrical structure

The molecular geometry of Cl2 is linear which is highly symmetrical and in straight lines. So, dipole generated in symmetrical shape can easily be canceled out. Also the equal number of lone pairs present on each chlorine atom in the Cl2 lewis structure.

So, both chlorine equally repels bonded pair of electrons and that creates overall balance in structure which ultimately makes it a highly symmetrical molecule.

All these factors show why Cl2 is a nonpolar molecule.

FAQ

How many sharing and non-sharing electrons present in the Cl2 lewis structure?

Sharing electrons we know that are available for bonding and non-sharing generally referred to as lone pairs of electrons because they don’t share electrons for making the chemical bond.

In the Cl2 lewis structure, one bond present between two chlorine atoms. As one bond contains two electrons, so 2 electrons are available for sharing.

And each chlorine contains three lone pairs. So, the total lone pair is 6 that makes 6*2 = 12 unshared electrons.   

Hence, sharing electrons in the Cl2 lewis dot structure is two and non-sharing electrons are 12.

What is the bond angle of Cl2?

The bond angle of Cl2 is 180º as its molecular geometry is linear which shows atoms lie in a straight line and make a 180º angle.

Summary

Chlorine gas is highly reactive and exists as a diatomic molecule that belongs to the halogen group. Here is a summary of what we have learned in this article.

  • The total valence electron available for drawing the Cl2 lewis structure is 14.
  • The hybridization of each chlorine atom in Cl2 is Sp³.
  • The formal charge of Chlorine in the Cl2 lewis dot structure is zero.
  • The molecular shape of Cl2 is linear.
  • Cl2 is non-polar in nature because of no dipole moment present in it.
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