# CCl3- Lewis structure

CCl3 has one carbon atom and three chlorine atoms.

In CCl3 Lewis structure, there are three single bonds around the carbon atom, with three chlorine atoms attached to it. Each chlorine atom has three lone pairs, and the carbon atom has one lone pair.

Also, there is a negative (-1) charge on the carbon atom.

Contents

## Steps

To properly draw the CCl3 Lewis structure, follow these steps:

#1 Draw a rough sketch of the structure
#2 Next, indicate lone pairs on the atoms
#3 Indicate formal charges on the atoms, if necessary

Let’s break down each step in more detail.

### #1 Draw a rough sketch of the structure

• First, determine the total number of valence electrons

In the periodic table, carbon lies in group 14, and chlorine lies in group 17.

Hence, carbon has four valence electrons and chlorine has seven valence electrons.

Since CCl3 has one carbon atom and three chlorine atoms, so…

Valence electrons of one carbon atom = 4 × 1 = 4
Valence electrons of three chlorine atoms = 7 × 3 = 21

Now the CCl3 has a negative (-1) charge, so we have to add one more electron.

So the total valence electrons = 4 + 21 + 1 = 26

• Second, find the total electron pairs

We have a total of 26 valence electrons. And when we divide this value by two, we get the value of total electron pairs.

Total electron pairs = total valence electrons ÷ 2

So the total electron pairs = 26 ÷ 2 = 13

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since carbon is less electronegative than chlorine, assume that the central atom is carbon.

Therefore, place carbon in the center and chlorines on either side.

• And finally, draw the rough sketch

### #2 Next, indicate lone pairs on the atoms

Here, we have a total of 13 electron pairs. And three C — Cl bonds are already marked. So we have to only mark the remaining ten electron pairs as lone pairs on the sketch.

Also remember that carbon is a period 2 element, so it can not keep more than 8 electrons in its last shell. And chlorine is a period 3 element, so it can keep more than 8 electrons in its last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are chlorines.

So for each chlorine, there are three lone pairs, and for carbon, there is one lone pair.

Mark the lone pairs on the sketch as follows:

### #3 Indicate formal charges on the atoms, if necessary

Use the following formula to calculate the formal charges on atoms:

Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons

For carbon atom, formal charge = 4 – 2 – ½ (6) = -1

For each chlorine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, the carbon atom has a charge, so mark it on the sketch as follows:

In the above structure, you can see that the central atom (carbon) forms an octet. And the outside atoms (chlorines) also form an octet. Hence, the octet rule is satisfied.

Now there is still a negative (-1) charge on the carbon atom.

This is not okay, right? Because the structure with a negative charge on the most electronegative atom is the best Lewis structure. And in this case, the most electronegative element is chlorine.

But if we convert a lone pair of the carbon atom to make a new C — Cl bond with the chlorine atom, and calculate the formal charge, then we do not get the formal charges on atoms closer to zero.

And the structure with the formal charges on atoms closer to zero is the best Lewis structure.

Therefore, this structure is the most stable Lewis structure of CCl3.

And since the CCl3 has a negative (-1) charge, mention that charge on the Lewis structure by drawing brackets as follows:

Next: NH2F Lewis structure

Deep

Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.