ClBr3 Lewis Structure in 5 Steps (With Images)

So you have seen the above image by now, right?

Let me explain the above image in short.

ClBr3 lewis structure has an Chlorine atom (Cl) at the center which is surrounded by three Bromine atoms (Br). There are 3 single bonds between the Chlorine atom (Cl) and each Bromine atom (Br). There are 2 lone pairs on the Chlorine atom (Cl) and 3 lone pairs on all three Bromine atoms (Br).

If you haven’t understood anything from the above image of ClBr3 lewis structure, then just stick with me and you will get the detailed step by step explanation on drawing a lewis structure of ClBr3.

So let’s move to the steps of drawing the lewis structure of ClBr3.

Steps of drawing ClBr3 lewis structure

Step 1: Find the total valence electrons in ClBr3 molecule

In order to find the total valence electrons in a ClBr3 molecule, first of all you should know the valence electrons present in the chlorine atom as well as bromine atom.
(Valence electrons are the electrons that are present in the outermost orbit of any atom.)

Here, I’ll tell you how you can easily find the valence electrons of chlorine as well as bromine using a periodic table.

Total valence electrons in ClBr3 molecule

→ Valence electrons given by chlorine atom:

Chlorine is group 17 element on the periodic table. ^[1] Hence the valence electrons present in chlorine is 7.

You can see the 7 valence electrons present in the chlorine atom as shown in the above image.

→ Valence electrons given by bromine atom:

Bromine is a group 17 element on the periodic table. ^[2] Hence the valence electrons present in bromine is 7.

You can see the 7 valence electrons present in the bromine atom as shown in the above image.

Hence, 

Total valence electrons in ClBr3 molecule = valence electrons given by 1 chlorine atom + valence electrons given by 3 bromine atoms = 7 + 7(3) = 28.

Step 2: Prepare the rough sketch

To draw the rough sketch of a ClBr3 molecule, just look at its chemical formula only. You can see that there is a chlorine atom (Cl) at the center and it is surrounded by three bromine atoms (Br).

So let’s draw a rough sketch for the same.

Step 3: Connect each atoms by putting an electron pair between them

Now in the ClBr3 molecule, you have to put the electron pairs between the chlorine atom (Cl) and bromine atoms (Br).

This indicates that the chlorine (Cl) and bromine (Br) are chemically bonded with each other in a ClBr3 molecule.

Step 4: Make the outer atoms stable. Place the remaining valence electrons pair on the central atom.

Now in this step, you have to check the stability of the outer atoms.

Here in the sketch of ClBr3 molecule, you can see that the outer atoms are bromine atoms.

These outer bromine atoms are forming an octet and hence they are stable.

Also, in step 1 we have calculated the total number of valence electrons present in the ClBr3 molecule.

The ClBr3 molecule has a total 28 valence electrons and out of these, only 24 valence electrons are used in the above sketch.

So the number of electrons which are left = 28 – 24 = 4.

You have to put these 4 electrons on the central chlorine atom in the above sketch of ClBr3 molecule.

Now let’s proceed to the next step.

Step 5: Check the stability of lewis structure

Now you have come to the final step in which you have to check the stability of lewis structure of ClBr3.

The stability of lewis structure can be checked by using a concept of formal charge.

In short, now you have to find the formal charge on chlorine (Cl) atom as well as bromine (Br) atoms present in the ClBr3 molecule.

For calculating the formal charge, you have to use the following formula;

Formal charge = Valence electrons – (Bonding electrons)/2 – Nonbonding electrons

You can see the number of bonding electrons and nonbonding electrons for each atom of ClBr3 molecule in the image given below.

For Chlorine (Cl) atom:
Valence electrons = 7 (because chlorine is in group 17)
Bonding electrons = 6
Nonbonding electrons = 4

For Bromine (Br) atom:
Valence electrons = 7 (because bromine is in group 17)
Bonding electrons = 2
Nonbonding electrons = 6

Formal charge	=	Valence electrons	–	(Bonding electrons)/2	–	Nonbonding electrons
Cl	=	7	–	6/2	–	4	=	0
Br	=	7	–	2/2	–	6	=	0

From the above calculations of formal charge, you can see that the chlorine (Cl) atom as well as bromine (Br) atom has a “zero” formal charge.

This indicates that the above lewis structure of ClBr3 is stable and there is no further change in the above structure of ClBr3.

In the above lewis dot structure of ClBr3, you can also represent each bonding electron pair (:) as a single bond (|). By doing so, you will get the following lewis structure of ClBr3.

I hope you have completely understood all the above steps.

For more practice and better understanding, you can try other lewis structures listed below.

Try (or at least See) these lewis structures for better understanding:

FCN Lewis Structure	HClO2 Lewis Structure
C2Cl4 Lewis Structure	CF3Cl Lewis Structure
PF3Cl2 Lewis Structure	C2H4Cl2 Lewis Structure