CHCl3 Lewis structure

CHCl₃ (chloroform) has one carbon atom, one hydrogen atom, and three chlorine atoms.

In the CHCl₃ Lewis structure, there are four single bonds around the carbon atom, with one hydrogen atom and three chlorine atoms attached to it, and on each chlorine atom, there are three lone pairs.

Alternative method: Lewis structure of CHCl₃

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, carbon lies in group 14, hydrogen lies in group 1, and chlorine lies in group 17.

Hence, carbon has four valence electrons, hydrogen has one valence electron, and chlorine has seven valence electrons.

Since CHCl₃ has one carbon atom, one hydrogen atom, and three chlorine atoms, so…

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

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

Learn how to find: Carbon valence electrons, Hydrogen valence electrons, and Chlorine valence electrons

• Second, find the total electron pairs

We have a total of 12 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

Here hydrogen can not be the central atom. Because the central atom is bonded with at least two other atoms, and hydrogen has only one electron in its last shell, so it can not make more than one bond.

Now we have to choose the central atom from carbon and chlorine. 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 hydrogen and chlorine on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 13 electron pairs. And four bonds are already marked. So we have to only mark the remaining nine 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. Hydrogen is a period 1 element, so it can not keep more than 2 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 hydrogen and chlorines. But no need to mark on hydrogen, because hydrogen already has two electrons.

So for each chlorine, there are three lone pairs, and for carbon, there is zero lone pair because all nine electron pairs are over.

Mark the lone pairs on the sketch as follows:

Formal charge

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 – 0 – ½ (8) = 0

For hydrogen atom, formal charge = 1 – 0 – ½ (2) = 0

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

Here, the atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of CHCl₃ features a central carbon atom connected to one hydrogen atom and three chlorine atoms through single covalent bonds. Within this configuration, the carbon atom satisfies the octet rule by forming four bonding pairs, while each chlorine atom fulfills its octet by maintaining three lone pairs of its own. The hydrogen atom reaches its stable duet state through the single shared electron pair with the central carbon. This setup is the most stable because it results in formal charges of zero for all atoms, representing the most energetically favorable state for the molecule. Consequently, this specific electronic distribution serves as the definitive and most accurate Lewis representation of chloroform.

Next: BrF₃ Lewis structure

External video

• CHCl3 Lewis Structure: How to Draw the Lewis Structure for CHCl3 – YouTube • Wayne Breslyn

External links

• https://geometryofmolecules.com/chcl3-lewis-structure-molecular-geometry-hybridization-bond-angle-and-shape/
• https://www.chemistryscl.com/general/CHCl3-lewis-structure/
• https://topblogtenz.com/chcl3-lewis-structure-molecular-geometry-polarity/
• https://techiescientist.com/chcl3-lewis-structure/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/CHCl3-lewis-structure.html
• https://lambdageeks.com/chcl3-lewis-structure/