CH2Cl2 Lewis structure

CH₂Cl₂ (dichloromethane) has one carbon atom, two hydrogen atoms, and two chlorine atoms.

In the CH₂Cl₂ Lewis structure, there are four single bonds around the carbon atom, with two hydrogen atoms and two chlorine atoms attached to it, and on each chlorine atom, there are three lone pairs.

Alternative method: Lewis structure of CH₂Cl₂

Contents

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 CH₂Cl₂ has one carbon atom, two hydrogen atoms, and two chlorine atoms, so…

Valence electrons of one carbon atom = 4 × 1 = 4
Valence electrons of two hydrogen atoms = 1 × 2 = 2
Valence electrons of two chlorine atoms = 7 × 2 = 14

And the total valence electrons = 4 + 2 + 14 = 20

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 20 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 = 20 ÷ 2 = 10

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

CH2Cl2 Lewis Structure (Step 1) — Rough sketch of CH₂Cl₂ Lewis structure | Image: Learnool

Lone pair

Here, we have a total of 10 electron pairs. And four bonds are already marked. So we have to only mark the remaining six 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 hydrogens and chlorines. But no need to mark on hydrogen, because each hydrogen has already two electrons.

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

Mark the lone pairs on the sketch as follows:

CH2Cl2 Lewis Structure (Step 2) — Lone pairs marked, and got the stable Lewis structure of CH₂Cl₂ | Image: Learnool

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 each 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 CH₂Cl₂ has carbon as the central atom, connected to two hydrogen atoms and two chlorine atoms through four single covalent bonds. This tetrahedral arrangement allows the carbon atom to satisfy the octet rule and each chlorine atom to complete its octet with three lone pairs, while the hydrogen atoms achieve their stable duets. With formal charges of zero on every atom, this configuration represents the most stable and chemically accurate Lewis representation of dichloromethane.

Next: ClO₂^– Lewis structure

External video

CH2Cl2 Lewis Structure: How to Draw the Lewis Structure for CH2Cl2 (Dichloromethane) – YouTube • Wayne Breslyn

External links

Deep