
ICl (iodine monochloride) has one iodine atom and one chlorine atom.
In the ICl Lewis structure, there is a single bond between the iodine and chlorine atoms, and on both iodine and chlorine atoms, there are three lone pairs.
Alternative method: Lewis structure of ICl
Rough sketch
- First, determine the total number of valence electrons

In the periodic table, both iodine and chlorine lie in group 17.
Hence, both iodine and chlorine have seven valence electrons.
Since ICl has one iodine atom and one chlorine atom, so…
Valence electrons of one iodine atom = 7 × 1 = 7
Valence electrons of one chlorine atom = 7 × 1 = 7
And the total valence electrons = 7 + 7 = 14
Learn how to find: Chlorine valence electrons
- Second, find the total electron pairs
We have a total of 14 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 = 14 ÷ 2 = 7
- Third, determine the central atom
We have to place the least electronegative atom at the center.
Since iodine is less electronegative than chlorine, assume that the central atom is iodine.
- And finally, draw the rough sketch

Lone pair
Here, we have a total of 7 electron pairs. And one I — Cl bonds are already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.
Also remember that iodine is a period 5 element, so it can keep more than 8 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 atom is chlorine.
So for each atom, there are three lone pairs.
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 iodine atom, formal charge = 7 – 6 – ½ (2) = 0
For chlorine atom, formal charge = 7 – 6 – ½ (2) = 0
Here, both iodine and chlorine atoms do not have charges, so no need to mark the charges.
Final structure
The final structure of ICl comprises an iodine atom linked to a chlorine atom through a single covalent bond. In this arrangement, both the iodine and chlorine atoms satisfy the octet rule by sharing one pair of electrons and retaining three lone pairs each. Within this layout, both halogen atoms achieve a stable valence shell configuration. This configuration represents the most stable state for the molecule because it results in a formal charge of zero for every atom involved. Accordingly, this specific electronic distribution serves as the definitive and most accurate Lewis representation of iodine monochloride.
Next: C22- Lewis structure
External video
- ICl Lewis Structure: How to Draw the Lewis Structure for the Iodine Chloride – YouTube • Wayne Breslyn
External links
- https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/ICl-lewis-structure.html
- https://lambdageeks.com/icl-lewis-structure/
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.