Chloroform (CHCl₃) Lewis Structure

Chloroform (CHCl₃) contains one carbon atom, three chlorine atoms and one hydrogen atom. In the lewis structure of CHCl₃, carbon atom is located as the center atom and other atoms have made bonds with carbon atom.

CHCl₃ lewis structure

There are three chlorine atoms around center carbon atom. Hydrogen atom has made a single bond with carbon atom and each chlorine atom has three lone pairs on their valence shell. As well, there are no charges on atoms in CHCl₃ lewis structure.

Steps of drawing lewis structure of CHCl₃

When we draw a lewis structure, there are several guidelines to follow. Number of steps can be changed according the complexity of the molecule or ion. However those all steps are mentioned and explained in detail in this tutorial for your knowledge.

1. Find total number of electrons of the valance shells of carbon, hydrogen and chlorine atoms
2. Determine total electrons pairs existing as lone pairs and bonds
3. Deciding center atom selection
4. Mark lone pairs on atoms
5. Mark charges on atoms if there are charges.
6. Check the stability and minimize charges on atoms by converting lone pairs to bonds to obtain best lewis structure.

Total number of electrons of the valance shells of CHCl₃

There are three elements in chloroform; carbon, hydrogen and chlorine. Hydrogen is a group IA element in the periodic table and only has one electron in its last shell (valence shell).Carbon is a group IVA element in the periodic table and has four electrons in its last shell (valence shell). Also, Chlorine is a group VIIA element in the periodic table and contains seven electrons in its last shell. Now, we know how many electrons are there in valence shells of hydrogen, carbon and chlorine atoms.

• valence electrons given by hydrogen atom = 1 * 1 = 1
• valence electrons given by carbon atom = 4 * 1 = 4
• valence electrons given by chlorine atoms = 7 * 3 = 21

• Total valence electrons = 1 + 4 + 21 = 26

Total valence electrons pairs

Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells

Total electron pairs are determined by dividing the number total valence electrons by two. For, CHCl₃, Total pairs of electrons are thirteen in their valence shells.

Center atom of CHCl₃

Hydrogen atom cannot be a center atom because hydrogen can only keep two electrons in last shell.

Because, carbon can show higher valance than oxygen, carbon has the higher chance to be the center atom in CHCl₃. Also, carbon is more electropositive than oxygen, it again proves, carbon should be the center atom in CHCl₃.

Lone pairs on atoms

After determining the center atom and sketch of CHCl₃ molecule, we can start to mark lone pairs on atoms. Remember that, there are total of thirteen electron pairs.

• There are already four bonds in the drawn skeletal. So, now only nine electron pairs are remaining to mark as lone pairs.
• Usually, those remaining electron pairs should be started to mark on outside atoms. Therefore, we can start to mark those remaining electrons pairs on chlorine atoms. Each chlorine atom will take three lone pair. Then, all remaining nine electron pairs are marked on three chlorine atoms.
• Now, there are no more lone pairs to mark on carbon atom.

Mark charges on atoms

There are no charges on atoms in above structure.

Check the stability and minimize charges on atoms by converting lone pairs to bonds

Because three are no charges on atoms, we do not need to do the step of reducing charges on atoms by converting lone pairs to bonds.

Questions