Chloromethane (CH3Cl) Lewis Structure
Chloromethane (CH3Cl) contains one carbon atom, three hydrogen atoms and one chlorine atom. In the lewis structure of CH3Cl, carbon atom is located as the center atom and other atoms have made bonds with carbon atom.
CH3Cl lewis structure
There are three hydrogen atoms around center carbon atom. Each hydrogen atom and chlorine atom have made single bonds with carbon atom. As well, chlorine atom has three lone pairs on its valence shell. Also there are no charges on atoms in CH3Cl lewis structure.
Steps of drawing lewis structure of CH3Cl
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.
- Find total number of electrons of the valance shells of carbon, hydrogen and chlorine atoms
- Determine total electrons pairs existing as lone pairs and bonds
- Deciding center atom selection
- Mark lone pairs on atoms
- Mark charges on atoms if there are charges.
- 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 CH3Cl
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 * 3 = 3
- valence electrons given by carbon atom = 4 * 1 = 4
- valence electrons given by chlorine atoms = 7 * 1 = 7
- Total valence electrons = 3 + 4 + 7 = 14
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, CH3Cl, total pairs of electrons are seven in their valence shells.
Center atom of CH3Cl
Hydrogen atom cannot be a center atom because hydrogen atom can only keep two electrons in last shell.
Because, chlorine can show higher valence (7) than carbon (4), we can think chlorine should be the center atom. But, due to carbon is more electropositive than chlorine and considering stability of molecule, carbon is the center atom. Basic skeletal of CH2Cl2 is shown below.
Lone pairs on atoms
After determining the center atom and sketch of CH3Cl molecule, we can start to mark lone pairs on atoms. Remember that, there are total of seven electron pairs.
- There are already four bonds in the drawn skeletal. So, now only three 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 because each hydrogen atom aleady has two electrons in their valence shell. Therefore, chlorine atom will take three lone pair. Then, all remaining three electron pairs are marked.
- 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 in above CH3Cl structure, we do not need to do the step of reducing charges on atoms by converting lone pairs to bonds.
Questions