Cl2O7 Lewis Structure & Characteristics (17 Important Facts)

Cl2O7 Lewis structure informs about several chemical facts regarding the formation of Dichlorine heptoxide. Let us define the Cl2O7 Lewis structure below.

Cl2O7 Lewis structure can be defined as the electronic representation of bond between two Chlorine (Cl) and seven Oxygen (O) atoms. The process of making bonds between Cl and O atoms are described by drawing Lewis structure. The structure is surrounded by electrons dots as valence electrons in Cl2O7.

Cl2O7 Lewis structure shares the chemical and several physical characteristics such as shape, angle and hybridisation of the compound.  The facts  behind holding those characteristics by Cl2O7 are going to be discussed throughout the article.

How to draw Cl2O7 Lewis structure?

Five core steps significantly follow drawing Lewis structure. Those steps are being arranged systematically in this section below.

Step 1: Number of valence electron calculation

Calculating the number of valence electron is the fundamental criterion for drawing the Lewis structure. Lewis structure is completely formed depending on the representation of valence electrons. Therefore, this is considered as the first step of drawing the Lewis structure of Cl2O7.

Step 2: Finding the lack of electrons in valence shell of atoms

After identifying the number of valence electron in each atom of Chlorine and Oxygen, the deficiency of electrons in the atoms would be clarified. This step signifies the sharing of electron between Cl and O in accordance with the requirement of electron in them.

Step 3: Choosing a central atom

Least electronegative atom gets the central position always. As Oxygen is more electronegative than Chlorine, one Oxygen out of seven similar atoms would get the centre position. The central Oxygen is paired with both Chlorine atoms in the Lewis structure, which denotes it shares electron with both CL here.

Step 4: Bond representation 

Representation of the bonds in Cl2O7 is done by putting two electron dots between Cl and O.  Three O atoms create double bonds with first Cl and other three create double bonds with second Cl. The remaining one creates single bonds with each Cl atoms. Double bonds are represented by four dots between atoms.

Step 5: Identification of lone pairs 

Lone pairs take place in O atoms as Cl use to make bonds with O atoms by using all of its valence electrons.  According to VSEPR (Valence Shell Electron Pair Repulsion) Theory, lone pair–lone pair repulsion affects the shape of compounds so it is important to count them after bonding in Lewis structure.

Cl2O7 Lewis structure shape

Shape defines the physical appearance of compounds with specific configuration of Lewis structure. Let us identify the shape of Cl2O7 below.

Cl2O7 Lewis structure has Bent shape. This shape is not the ideal one for the compound. The lone pairs on oxygen atoms make the shape bent and a curvy appearance in Cl atoms with central O that take place as a bridge in the compound. This is key reason for possessing bent shape by Cl2O7.

Cl2O7 Lewis structure formal charge

Formal charge calculation refers to the identification of neutral state of the compounds. Let us signify this factor for Cl2O7.

The formal charge of Cl2O7 is 0. Formal charge calculation for Cl2O7 would be followed by the general formula. Formal charge = number of valence electrons – number of nonbonding electrons – number of electron shared (number of bonding electrons/2)

The table created below is highlighting the whole calculation:

Elements and
the number
of their
valence electrons
Number of
Number of
electron shared
Formal charge
Cl1 = 70(7/2) = 3.5(7-0-3.5) = 3.5
Cl2 = 70(7/2) = 3.5(7-0-3.5) = 3.5
O1 = 64(2/2) = 0(6-4-0) = 2
O2 = 64(2/2) = 0(6-4-0) = 2
O3 = 64(2/2) = 0(6-4-0) = 2
O4 = 64(2/2) = 0(6-4-0) = 2
O5 = 64(2/2) = 0(6-4-0) = 2
O6 = 64(2/2) = 0(6-4-0) = 2
O7 = 64(2/2) = 0(6-4-0) = 2
Cl2O7 = 560
Formal Charge calculation of Cl2O7 Lewis structure

Cl2O7 Lewis structure angle

Angle of Lewis structure demotes the angle between bonds of ligands and central atoms. Let us find the bond angle of Dichlorine heptoxide below.

Cl2O7 Lewis structure has bond angle of 118.6o. This is not an ideal bond angle for any compound.  The presence of lone pairs distinguishes the idealist bond angle of the compound. According to VSEPR theory, the lone pair- lone pair repulsion creates a hustle around terminals in Cl2O7 that lowers the angle.

Cl2O7 Lewis structure octet rule

Octet rule states that having eight-electron n the valence shell givens stability top periodic elements. Let us find how Cl2O7 follow this rule.

Cl2O7 Lewis structure follows octet rule by  filling the valence shells of Cl and O atoms with eight electrons. This criterion of having eight electrons brings forth similar electronic configuration as their nearest noble gas. This rule drives the elements to share valence electrons and make bonds together.

Cl2O7 Lewis structure lone pairs

Lone pairs contain valence electrons that remain free after the elements make bonds by sharing some electrons with each other.  Let us find the number of lone pairs in Cl2O7.

Cl2O7 Lewis structure has total 14 lone pairs in its electronic geometry. Each of the Oxygen has two lone pairs so seven Oxygen atoms hold total (7*2 = 14) lone pairs.  Chlorine atoms use all its valence electrons to make bonds with Oxygen atoms. These lone pairs effect on bond angle and shape of Cl2O7.

Cl2O7 valence electrons

Valence electrons help to make bonds between the elements. The number of valence electrons in both Cl and O atoms in Cl2O7 identifies the lack of electrons in them below.

The total number of valence electron in Cl2O7 is 56. The calculation is shared below:

  • The number of valence electron each Chlorine atoms = 7
  • Total number of valence election in two Chlorine atoms = (7*2) = 14
  • The number of valence electron in each Oxygen atom = 6
  • Total number of valence electron in 7 Oxygen atoms = (7*6) = 42
  • The total number if valence electron in Cl2O7 = (14+42 = 56)

Cl2O7 hybridization

Hybridisation is a vital factor that implicates the state of overlapped orbitals of atoms after making bonds. Let us identify the hybridisation state of Cl2O7.

Cl2O7 is a Sp3 hybridised compound. Both of Oxygen and Chlorine holds sp3 hybridisation individually. Therefore, after making bonds the arrangement of electrons is done among the s and p orbitals of atoms. The steric number of the compound can justify sp3 hybridisation.

Steric number if compounds are calculated by adding the number of lone pair and bonded electrons on the central atom. The steric number of Cl2O7 is (2+2) = 4. According to VSEPR theory, 4 steric number signifies that the central atom is sp3 hybridised in the compound.

Is Cl2O7 solid or liquid?

Solid or liquid state of compounds are defined by the internal bond strength between element of the same let us identify the general state of Cl2O7 below.

Cl2O7 Is found as a Colourless liquid. It refers that the internal bonding of the compound is not much intact to bind the molecules tightly. Lightly closed elements make the compound appear in liquid state. In addition, the lone-pair-lone pair repulsion inside it reduces its bond strength.

Is Cl2O7 soluble in water?

Solubility of water defines the nature of compound through the rate of being dissolved in water or hydrolysed in molten state. Let us find this fact if justified for CL2O7.

Cl2O7 is quite soluble in water. This compound is noticed to slowly hydrolyse in water, which is opportune the property of every molecule in the series of chlorine oxides. The anhydride compound hydrolyses in water molecule to give out Perchloric acid (HClO4).

Is Cl2O7 polar or nonpolar?

Polarity or non-polarity refers to a tension inside the compounds at their terminal position, which affects its shape and bond angle. Let us signify the characteristic for CL2O7.

Cl2O7 can be refers as a polar compound.  Polarity of the compound can be measures as per its bent shape. The amount of dipole moment of the compound cannot be measured exactly as the tension in both sides of Dichlorine heptoxide differs.

Is Cl2O7 molecular compound?

Molecular compounds are defined by their neutral appearance in chemical study. let us examine the appearance of Cl2O7 below if it is molecular or not.

Cl2O7 is a Molecular by nature. The compound does not contain any negative or positive charge in it. Moreover, two Chlorine and seven Oxygen molecules form which as specific molecular formula it holds 182.902 gram of molecular weight and it, which also signifies the composition as molecular.

cl2o7 lewis structure
Molecular state of Cl2O7 Lewis structure from Wikipedia

Is Cl2O7 acid or base?

Acidity or basicity is the general chemical properties of a compound. Let us identify the chemical nature of Dichlorine heptoxide below.

Cl2O7 is highly capable of reflecting its acidic nature in presence of water. The compound deliberately forms acid when it is kept in contact with water molecule. The reaction of Cl2O7 with water gives out Perchloric acid, which refers to its acidic property. The solution also turns blue litmus red.

Is Cl2O7 electrolyte?

Electrolytic property is shown by the compounds, which have charged molecules in molecular geometry.  Let us identify if Cl2O7 is molecular or not below.

Cl2O7 is non-electrolyte compound. Dichlorine heptochloride does not have any charge in it, which makes it completely neutral, and disable to conduct electricity. This anhydride in soluble in water and does not discharge ions in molten state so it cannot be called an electrolyte substance in chemistry.

Is Cl2O7 salt?

Salts are generally found solid in state and highly soluble in water. Let us find if Cl2O7 shows any property of salts in its natural state through this section.

Cl2O7 cannot be considered as a salt. Salts must have solid format and Dichlotione heptoxide is liquid. Besides, the compound has very low meting point, less than -90oC and low boiling point, 82oC. Moreover, Cl2O7 is not ionic and these factors significantly denote that the compound cannot be called salt.  

Is Cl2O7 ionic or covalent?

Ionic and covalent natures of compounds are highly dependent on the process of bonding. This section will help us out to find the bonding structure of Cl2O7.

Cl2O7 is completely a covalent compound. It means that this compound is created by the formation of covalent bond between Chlorine and Oxygen atoms. The compound is covalent because the bonds are formed by valence electron sharing process among Choline and Oxygen atoms.


This article has delivered the significance of having bent shape by Cl2O7. It is deviated from several factors by its chemical characteristics in chemistry. It is an anhydride of Perchloric acid which Cl2O7 quite an epic compound in the series of chlorine oxides.

Sarnali Mukherjee

Hi.....I am Sarnali Mukherjee, a graduate from the University of Calcutta. I love to teach and share knowledge on chemistry. I have gradually gained interest in article writing since one year ago. I would love to acquire more knowledge on my subject in the future. Let's connect through LinkedIn:

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