
CHClO (formyl chloride) has one carbon atom, one hydrogen atom, one chlorine atom, and one oxygen atom.
In CHClO Lewis structure, there is one double bond and two single bonds around the carbon atom, with one oxygen atom, one hydrogen atom, and one chlorine atom attached to it. The chlorine atom has three lone pairs, and the oxygen atom has two lone pairs.
Alternative method: Lewis structure of CHClO
Rough sketch
- First, determine the total number of valence electrons

In the periodic table, carbon lies in group 14, hydrogen lies in group 1, chlorine lies in group 17, and oxygen lies in group 16.
Hence, carbon has four valence electrons, hydrogen has one valence electron, chlorine has seven valence electrons, and oxygen has six valence electrons.
Since CHClO has one carbon atom, one hydrogen atom, one chlorine atom, and one oxygen atom, so…
Valence electrons of one carbon atom = 4 × 1 = 4
Valence electrons of one hydrogen atom = 1 × 1 = 1
Valence electrons of one chlorine atom = 7 × 1 = 7
Valence electrons of one oxygen atom = 6 × 1 = 6
And the total valence electrons = 4 + 1 + 7 + 6 = 18
Learn how to find: Carbon valence electrons, Hydrogen valence electrons, Chlorine valence electrons, and Oxygen valence electrons
- Second, find the total electron pairs
We have a total of 18 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 = 18 ÷ 2 = 9
- 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, chlorine, and oxygen. Place the least electronegative atom at the center.
Since carbon is less electronegative than chlorine and oxygen, assume that the central atom is carbon.
Therefore, place carbon in the center and hydrogen, chlorine, and oxygen on either side.
- And finally, draw the rough sketch

Lone pair
Here, we have a total of 9 electron pairs. And three bonds are already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.
Also remember that hydrogen is a period 1 element, so it can not keep more than 2 electrons in its last shell. Both (carbon and oxygen) are the period 2 elements, so they can not keep more than 8 electrons in their 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, oxygen, and chlorine. But no need to mark on hydrogen, because hydrogen already has two electrons.
So for oxygen and 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:

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 (6) = +1
For hydrogen atom, formal charge = 1 – 0 – ½ (2) = 0
For chlorine atom, formal charge = 7 – 6 – ½ (2) = 0
For oxygen atom, formal charge = 6 – 6 – ½ (2) = -1
Here, both carbon and oxygen atoms have charges, so mark them on the sketch as follows:

The above structure is not a stable Lewis structure because both carbon and oxygen atoms have charges. Therefore, reduce the charges (as below) by converting lone pairs to bonds.
Convert a lone pair of the oxygen atom to make a new C — O bond with the carbon atom as follows:

Final structure
The final structure of CHClO features a central carbon atom linked to a hydrogen atom through a single covalent bond, a chlorine atom through a single covalent bond, and an oxygen atom through a double covalent bond. In this arrangement, the carbon atom satisfies the octet rule by forming a total of four bonds, while the oxygen atom completes its octet by retaining two lone pairs. The chlorine atom also fulfills the octet rule by maintaining three lone pairs, and the hydrogen atom achieves its stable duet. This specific configuration is the most stable because it results in formal charges of zero for all participating atoms, representing the most energetically favorable state for the molecule. Consequently, this electronic distribution serves as the definitive and most accurate Lewis representation of formyl chloride.
Next: PCl4– Lewis structure
External video
- CHClO Lewis Structure: How to Draw the Lewis Structure for CHClO – YouTube • Wayne Breslyn
External links
- https://lambdageeks.com/chclo-lewis-structure/
- https://www.chegg.com/homework-help/questions-and-answers/draw-electron-dot-structure-chclo-note-carbon-central-atom-three-atoms-h-cl-o-attached-car-q7370269
- https://homework.study.com/explanation/part-a-draw-the-electron-dot-structure-for-chclo-draw-the-molecule-by-placing-the-atoms-on-the-grid-and-connecting-them-with-bonds-include-all-lone-pairs-of-electrons-part-b-what-is-the-elect.html
- https://oneclass.com/homework-help/chemistry/7034077-chclo-lewis-dot-structure.en.html
- https://brainly.com/question/6137470
- https://www.answers.com/Q/Electron-dot_structure_for_CHClO
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.