CCl4 Lewis Structure, Characteristics: 13 Facts You Should Know


In this article, we should discuss 13 important and detailed facts about the CCl4 lewis structure.

Carbon tetrachloride is often referred to as tetrachloromethane also. In the CCl4 lewis structure, we can observe that the molecule is tetrahedral shaped and central C is sp3 hybridized. As it is sp3 hybridized so its bond angle is expected to be 109.50 and there is no deviation in the bond angle.

Carbon tetrachloride behaves like an organic molecule as it is synthesized from methane. The C-Cl bond length is 177 pm. It acts as a solvent in many organic reactions. In the NMR study, it is the most important solution to be used.

Some important facts about CCl4

CCl4 is a colorless and slightly sweet smell liquid having a molar mass of 153.81 g/mol. The melting point and boiling point of the molecule are 250.23 K and 349.87 k respectively. Practically it is noon flammable in nature so it is used as a fire extinguisher in some cases.

It can be synthesized from methane by chlorination in the presence of sunlight.

CCl4 lewis structure
CCl4 Synthesis

In the laboratory, it can be prepared by the chlorination of carbon disulfide in the presence of high temperatures.

CS2 + 3Cl2 = CCl4 + S2Cl2

It is using as a dry cleaning agent.

1.    How to draw the CCl4 lewis structure?

It is important to draw the CCl4 lewis structure to predict the number of electrons involved in the bond formation or the number of lone pairs.

CCl4 Lewis Structure

To draw the CCl4 lewis structure we should look at some points. 1st of all we should count the valence electrons for C as well as 4 Cl atoms. Then we have to decide on the central atom based on electronegativity. As C is less electronegative than Cl so C is the central atom here.

In the CCl4 lewis structure, the total electrons involved 4+(7*4) =32, and the electrons needed according to the lewis dot formula, 5*8 = 40, so the bonding electrons will be 40-32 = 8 electrons and the number of bonds will be 8/2 = 4 bonds.

So, here C is attached to four Cl atoms via four sigma bonds, and no need to attach double or multiple bonds. 3 pairs of lone pairs are assigned to every cl atom.

2.    CCl4 lewis structure shape

The valence electrons for C involved in bond formation will be 4 and 4 Cl atoms each contributing 1 electron, so the total electrons participating in bond formation will be 4+ (4*1) = 8, so according to VSEPR theory if the electron count for a molecule is 8 then it adopts tetrahedral shape.

CCl4 Lewis Structure

In the CCl4 lewis structure, the whole electron density of the molecule is lie around the central C only. The molecule adopts a tetrahedral shape and C is present at the central position where four cl atoms are present at the four corner sites of a tetrahedral. The bond angle is perfectly 109.50 which is ideal for tetrahedral geometry.

3.    CCl4 valence electrons

In the CCl4 lewis structure, C and Cl contain valence electrons in their outermost orbitals.

CCl4 Valence Electrons

In the CCl4 lewis structure, we can see that C contributes four electrons in bond formation which are present at its valence shell.

Cl is a VIIA group element so it has seven electrons in its valence shell but it contributes only one electron in bond formation with C, so the rest of the six electrons lies as lone pairs over it.

 So, the total valence electrons in the CCl4 lewis structure is (7*4)+4 = 32 electrons.

4.    CCl4 lewis structure formal charge

From the CCl4 lewis structure, we see that the molecule is neutral so no formal charge over any atom is present.

The formula we can use to calculate the formal charge, F.C. = Nv – Nl.p. -1/2 Nb.p.

Where Nv is the number of electrons in the valence shell or outermost orbital, Nl.p is the number of electrons in the lone pair, and Nb.p  is the total number of electrons that are involved in the bond formation only.

For calculating the formal charge, we consider that all the atoms have the same electronegativity as a molecule.

Here all the Cl atoms are equivalent so we need to calculate the formal charge for only one cl atom and central c atom.

The formal charge accumulates by the Cl atom is 7-6-(2/2) = 0

The formal charge accumulated by the C atom is 4-0-(8/2) = 0

So, the overall formal charge of the molecule is zero, it is also reflected from the CCl4 lewis structure which is neutral.

5.    CCl4 lewis structure lone pairs

In the CCl4 lewis structure, there are lone pairs present only over Cl atoms, they are present in the valence shell of Cl but do not participate in bond formation.

CCl4 Lone Pairs

The C has four electrons in its valence shell, all the electrons are involved in bond formation so there is no chance of lone pairs for C. But Cl has seven electrons in its valence shell, out of seven only one electron is involved in sigma bond formation with C, and the rest of the six electrons are present as three pairs of lone pairs.

For Chlorine one bond pair and three lone pairs are present and there is four Cl atoms present and the entire scenario will be the same.

So, in the CCl4 lewis structure, the total number of lone pairs is 0+ (4*3)= 12 lone pairs present.

6.    CCl4 lewis structure octet rule

In the CCl4 lewis structure, C and Cl both try to complete their valence shell but accept or share electrons which lead to gain the nearest noble gas configuration according to the octet rule.

CCl4 Octet

In the CCl4 lewis structure, the electronic configuration of C is [He]2s22pso it has four electrons in its valence shell and all the electrons are getting involved in bond formation via one-electron share with four Cl each. So, C complete its octet.

Again, for Cl, the electronic configuration is [Ne]3s23p5, so it has seven electrons in its valence shell, during bond formation it shares one electron with C to complete its octet too.

7.    CCl4 lewis structure bond angle

According to VSEPR theory, a molecule that has 8 electrons counts generally adopts tetrahedral geometry and the expected bond angle will be 109.50.

C and four Cl makes that angle to maintain the perfect geometry moiety for tetrahedral and minimize all kind of repulsion factor.

CCl4 Bond Angle

In the CCl4 lewis structure, The Cl-C-Cl bond angle is here 109.50 according to the VSEPR theory in the tetrahedral molecules.

In the Tetrahedral moiety there is enough space to arrange the four Cl atoms with their lone pairs, so in the CCl4 lewis structure are no lone pairs- bond pairs repulsion occurs and the angle is perfectly 109.50. Also, we can evaluate the bond angle according to the Bents’s rule in the hybridization section.

8.    CCl4 lewis structure resonance

In the CCl4 lewis structure electrons, and clouds of four Cl atoms are delocalized in the molecule of different skeleton structures.

CCl4 Resonating Structure

Structure II of the CCl4 lewis structure is one of the resonating structures. But it is not the most contributing structure although it contains a higher number of covalent bonds simultaneously opposite charges are present with opposite substituents. Cl is one of the stronger electronegative elements and contains a positive charge which is the destabilization factor.

Thus, there are stabilization and destabilization factors present in structure II and making it neutral so, the most contributing structure is Structure I in the CCl4 lewis structure.

9.    CCl4 hybridization

In the CCl4 lewis structure, C and four Cl atoms undergo hybridization to mix their orbital and formed a new hybrid orbital of equivalent energy.

We calculate the CCl4 hybridization by using the following formula,

H = 0.5(V+M-C+A), where H= hybridization value, V is the number of valence electrons in the central atom, M = monovalent atoms surrounded, C=no. of cation, A=no. of the anion.

For the CCl4 lewis structure, C has four valence electrons and four Cl atoms surrounded and no charge appears on the molecule.

So, the hybridization of central C in the CCl4 lewis structure is ½(4+4+0+0) = 4 (sp3)

Structure        Hybridization value  State of hybridization of central atom   Bond angle
Linear       2sp /sd / pd     1800
Planner trigonal 3sp2                   1200
Tetrahedral    4sd3/ sp3       109.50
Trigonal bipyramidal 5sp3d/dsp3          900 (axial), 1200(equatorial)
Octahedral    6sp3d2/ d2sp3  900
Pentagonal bipyramidal7sp3d3/d3sp3      900,720

             

                                                                                                              

From the above table of hybridization, we can conclude that if the hybridization value is 4 then the central atoms is sp3 hybridized.

CCl4 Hybridization

In the ground state C has four electrons in its valence shell two in the 2s orbital and the remaining two in the 2p orbital. In the excited state one electron from the 2s orbital gets promoted to the 2p orbital and now C has four unpaired electrons and they are involved in bond formation with Cl by hybridization.

Here one s and three p orbitals are involved so the hybridization is sp3. From the box digram of the CCl4 lewis structure, we only consider the sigma bond not the π bond in hybridization.

According to the Bent’s rule, we can predict the bond angle via hybridization using the formula,

COSθ =s/s-1, where s is the % of s character in hybridization and θ is the bond angle.

In the CCl4 lewis structure, the molecule sp3 hybridized so here % of s is 25% or 1/4th.

Now using the formula, we get, COSθ = (¼)/(1/4)-1

Θ= 1090, so we can say that from the hybridization value we can evaluate the bond angle of a molecule or vice versa. Again, from VSEPR  theory the bond angle for a tetrahedral-shaped molecule will be 109.50.

10.    CCl4 solubility

Carbon tetrachloride itself is a non-polar solvent for organic molecules. In the CCl4 lewis structure, the molecule behaves as the solvent itself.

It is a nonpolar solvent so all the nonpolar molecule mainly organic molecule is soluble in it. It used the basic solution in the NMR study.

But it is soluble in a nonpolar solvent like benzene, or ethanol.

11.    Is CCl4 ionic?

From Fajan’s rule, we can say that every covalent molecule has some % of ionic character. The size of the C is small so it can polarize the moderately large anion chloride and chloride itself is polarizable so they have some sort of ionic character. On the other hand, we can say that the ionic potential of C is moderate so the molecule possesses an ionic character.

12.    Is CCl4 acidic or basic?

In the aqueous medium, CCl4 is neither acidic nor basic. From the CCl4 lewis structure, we can see that there is no factor present in CCl4 to make it acidic or basic.

It is used as a solvent only.

13.      Is Ccl4 polar or nonpolar?

CCl4 is a non-polar molecule due to its symmetric shape. For the polarity of a molecule, it should have some resultant dipole moment. But in the CCl4 lewis structure, we can see that it is symmetric for the four directions. So, there is no dipole moment, which makes the molecule nonpolar.

CCl4 Dipole Moment

Dipole moment acts from less electronegative to more electronegative substituents. Here in the CCl4 lewis structure, the dipole moment acts from C to Cl site, and from the above diagram, it is clearly shown that all the dipole moment directions are opposite and they canceled out each other and the resultant dipole moment would be zero and the molecule is non-polar.

SiCl4 can be hydrolyzed but CCl4 cannot. Why?

Si has vaccant d orbital in its shell. So, the lone pair of oxygen in the water molecule can be attacked on that vacant site of Si. Again, Si has a larger size than c so it can increase its coordination number to minimize the steric factor.

But C lacks a vacant orbital and due to its small size, it cannot increases its coordination number so there is no chance of hydrolysis in CCl4.

Conclusion

From the above discussion of the CCl4 lewis structure, we can conclude that due to symmetric structure it has zero dipole moment so the molecule is nonpolar. From the hybridization, we can find out the bond angle of the molecule and from VSEPR theory the shape of the molecule can be predicted.

Biswarup Chandra Dey

Chemistry is not all about reading line by line and memorize, it is a concept to understand in easy way and here I am share with you the concept about chemistry which I learn because knowledge is worth to share it.

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