BrCl (bromine monochloride) has one bromine atom and one chlorine atom. In the lewis structure of BrCl, there is a single bond between the bromine and chlorine atom, and on both bromine and chlorine atoms, there are three lone pairs.
Here’s how you can draw the BrCl lewis structure step by step.
Step #1: draw sketch
Step #2: mark lone pairs
Step #3: mark charges (if there are)
Let’s break down each step in detail.
#1 Draw Sketch
- First, determine the total number of valence electrons
Hence, both bromine and chlorine have seven valence electrons.
Since BrCl has one bromine atom and one chlorine atom, so…
Valence electrons of one bromine atom = 7 × 1 = 7
Valence electrons of one chlorine atom = 7 × 1 = 7
And the total valence electrons = 7 + 7 = 14
- 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 bromine is less electronegative than chlorine, assume that the central atom is bromine.
- And finally, draw the rough sketch
#2 Mark Lone Pairs
Here, we have a total of 7 electron pairs. And one Br — Cl bond is already marked. So we have to only mark the remaining six electron pairs as lone pairs on the sketch.
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:
#3 Mark Charges
Use the following formula to calculate the formal charges on atoms:
Formal charge = valence electrons – nonbonding electrons – ½ bonding electrons
For bromine atom, formal charge = 7 – 6 – ½ (2) = 0
For chlorine atom, formal charge = 7 – 6 – ½ (2) = 0
Here, both bromine and chlorine atoms do not have charges, so no need to mark the charges.
And in the above structure, you can see that the central atom (bromine) forms an octet. Hence, the octet rule is satisfied.
Therefore, this structure is the stable lewis structure of BrCl.
Next: BeI2 Lewis Structure