CCl2F2 or CF2Cl2 Lewis structure is made up of one carbon (C) atom, two fluorine (F), and two chlorine (Cl) atoms. The carbon (C) atom is kept at the central position and other atoms are at the surrounding position. The lewis structure of CF2Cl2 contains 4 single bonds in the form of two C-F bonds and two C-Cl bonds.
The drawing process of the CF2Cl2 lewis structure is easy and simple. Let’s see how to do it.
Follow some steps for drawing the Lewis dot structure for CF2Cl2 or CCl2F2
1. Count total valence electron in CF2Cl2
In the very first step, we will count the total valence electron in the CF2Cl2 molecule. To calculate the valence electron, look at the periodic group of the individual atoms – carbon, fluorine, and chlorine.
The chlorine and fluorine atom belongs to the periodic group 7A or 17th in the periodic table, hence, the valence electron for both these atoms is 7.
The carbon atom is situated in the 14 or 4A periodic group, hence, its valence electron is 4.
∴ Total number of valence electrons available for the CF2Cl2 Lewis structure = 4 + 7(2) + 7(2) = 32 valence electrons [∴ CF2Cl2 molecule has one carbon, two fluorine, and two chlorine atoms]
2. Find the least electronegative atom and place it at center
Now we will find the least electronegative atom in the CF2Cl2 compound, after that, we will place it at the center in the lewis diagram and the rest atoms will be spread around it.
The electronegativity value of the carbon atom is 2.55, for a chlorine atom, it is 3.16. And for fluorine atoms, the electronegativity is 3.98.
Hence, the carbon atom is the least electronegative atom in the CF2Cl2 compound, therefore, we will put the carbon atom at a central position and (chlorine and fluorine atom) at the surrounding position in the lewis diagram.
3. Connect outer atoms to central atom with a single bond
In this step, we simply connect each outer atom(chlorine and fluorine) to the central atom(carbon) with the help of a single bond.
Now count the valence electron used in the above structure. A single bond means two electrons, in the above structure, four single bonds are used for connecting the two chlorine and two fluorine atom to the carbon central atom.
Therefore, (4 single bonds × 2) = 8 valence electrons are used in the above structure from the total of 32 valence electrons available for drawing the lewis structure of CF2Cl2.
∴ (32 – 8) = 24 valence electrons
So, we are left with 24 valence electrons more.
4. Place remaining electrons on outer atoms and complete their octet
In this step, we will put the remaining valence electron on the outer atom first for completing their octet. In a CF2Cl2 molecule, the outer atom is fluorine and chlorine. And both these require 8 electrons in their outer shell to complete the octet.
As you see in the above figure, we have placed the 6 electrons represented as dots around each outer atom(chlorine and fluorine). This is because chlorine and fluorine atoms already have 2 electrons(one single bond) in their outer shell.
Hence, both these only require 6 more electrons for completing the octet.
Now once again count the total valence electron in the above structure.
(4 single bond × 2 electrons + 24 electrons represented as dots) = 32 valence electrons are used in the above structure.
Remember, we had a total of 32 valence electrons available for drawing the lewis structure of CF2Cl2, and in the above structure, we used all valence electrons.
Also, the Carbon central atom has completed its octet as well since it has connected with 4 single bonds(8 electrons).
Now just check the formal charge for the above structure to know whether it is stable or not.
5. Check the stability with the help of a formal charge concept
The lesser the formal charge on atoms, the better is the stability of the lewis diagram.
To calculate the formal charge on an atom. Use the formula given below-
⇒ Bonding electrons around carbon (4 single bonds) = 8
∴ (4 – 0 – 8/2) = 0 formal charge on the carbon central atom.
CCl2F2 or CF2Cl2 Lewis structure
So, all atoms in the above structure get a formal charge equal to zero, hence, this is our most stable and appropriate lewis structure of CF2Cl2 or CCl2F2.
The molecular geometry of CF2Cl2 is tetrahedral. The central atom Carbon (C) is bonded with four atoms (two fluorine and two chlorine atoms) and it has no lone pair which means, it is an AX4 type molecule, as per VSEPR theory, its geometry is tetrahedral.
A represent central atom
X represent the number of bonded atom to central atom
According to VSEPR theory or chart, the AX4 type molecule forms tetrahedral molecular geometry or shape.
Hybridization of CF2Cl2
We can calculate the hybridization of CF2Cl2 using the steric number formula given below:
∴ Steric number of CF2Cl2 = (Number of bonded atoms attached to carbon + Lone pair on carbon atom)
As per the CF2Cl2 lewis structure, the carbon atom is bonded with four atoms(two chlorine and two fluorine) and contains zero lone pairs.
∴ Steric number of CF2Cl2 = (4 + 0) = 4
So, for the steric number of 4, we get the hybridization of CF2Cl2 is Sp3.
Is CF2Cl2 polar or nonpolar?
Is CF2Cl2 polar or non-polar? CF2Cl2 is a polar molecule. This is because of the asymmetrical structure that causes uneven charge distribution and that contributes to the nonzero dipole moment and makes this molecule (CF2Cl2) polar in nature.
Also, the carbon atom gets a positive charge because of its less electronegativity, and both (chlorine and fluorine) atom gets a negative charge because of their high electronegativity.
The electronegativity for carbon atom is 2.55, for chlorine, it is 3.16, and for fluorine, it is 3.98.
The separation of positive and negative charges leads to the dipole moment in CF2Cl2 and these dipole moments will not be canceled out because their magnitude is different. (Since F is more electronegative than Cl, C-F bonds are more polar than C-Cl bonds). Hence, due to the non-zero dipole moment, the CF2Cl2 molecule will be polar.
How many bonding pairs and lone pairs are present in the lewis structure of CF2Cl2?
Bonding pairs are the pair of electrons that are in a bond. A single bond has one bond pair means 2 bonding electrons.
Lone pairs are those represented as dots in the lewis diagram that do not take part in the formation of bonds and are also called nonbonding electrons.
By looking at the CF2Cl2 lewis structure, we see there are 4 single bonds means 4 bonding pairs, and there are 24 dots electrons means 12 lone pairs. [∴ 2 dot electrons means one lone pair).
So, in the CF2Cl2 lewis structure, there are 12 lone pairs and 4 bonding pairs present.
Is CCl2F2 or CF2Cl2 lewis’s structure is same?
Yes, the lewis structure for CF2Cl2 and CCl2F2 is the same, since, they are the same molecule with the same number of valence electrons.
The only difference is Chlorine and fluorine is swapped from their position.
Why CF2Cl2 is polar?
CF2Cl2 has a tetrahedral geometry that is not symmetrical because side atoms are different, hence, the magnitude of the dipole moment for C-F and C-Cl bonds will be different, which causes a non-zero net dipole moment and makes CF2Cl2 polar in nature.
In the presence of a catalytic amount of antimony pentachloride, when one mole of carbon tetrachloride reacts with 2 moles of hydrogen fluoride, it forms one mole of CF2Cl2 and 2 moles of hydrogen chloride.
⇒ CCl4 + 2HF → CF2Cl2 + 2HCl
Properties and uses of CF2Cl2
The boiling point of CF2Cl2 is −29.8 °C and its melting point is −157.7 °C.
It is soluble in alcohol, ether, benzene, acetic acid.
Its dipole moment is 0.51 D.
It is a non-flammable and colorless gas.
CF2Cl2 is banned in many countries because of its harmful effect on the Ozone layer.
CF2Cl2 is used as an aerosol-like body spray.
It is used in household cleaning products.
It is used as a fire retardant in submarines and aircraft.
Summary
The total valence electron is available for drawing the CF2Cl2 lewis structure is 32.
The steric number of the carbon central atom in the CF2Cl2 molecule is 4, thus, it forms Sp3 hybridization.
CF2Cl2 is a polar molecule, its geometry is tetrahedral which is asymmetrical because of different side atoms, it will cause a non-zero dipole moment, which makes the CF2Cl2 polar molecule in nature.
Its dipole moment is 0.51 D.
In the CF2Cl2 or CCl2F2 lewis structure, a total of 12 lone pairs and 4 bond pairs are present.
The molecular geometry or shape of CF2Cl2 is tetrahedral.
Vishal Goyal is the founder of Topblogtenz, a comprehensive resource for students seeking guidance and support in their chemistry studies. He holds a degree in B.Tech (Chemical Engineering) and has four years of experience as a chemistry tutor. The team at Topblogtenz includes experts like experienced researchers, professors, and educators, with the goal of making complex subjects like chemistry accessible and understandable for all. A passion for sharing knowledge and a love for chemistry and science drives the team behind the website. Let's connect through LinkedIn: https://www.linkedin.com/in/vishal-goyal-2926a122b/
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CCl2F2 or CF2Cl2 Lewis structure
