BrCl2- Lewis structure

BrCl₂^– has one bromine atom and two chlorine atoms.

In BrCl₂^– Lewis structure, there are two single bonds around the bromine atom, with two chlorine atoms attached to it, and each atom has three lone pairs.

Also, there is a negative (-1) charge on the bromine atom.

Alternative method: Lewis structure of BrCl₂^–

Rough sketch

• First, determine the total number of valence electrons

In the periodic table, both bromine and chlorine lie in group 17.

Hence, both bromine and chlorine have seven valence electrons.

Since BrCl₂^– has one bromine atom and two chlorine atoms, so…

Valence electrons of one bromine atom = 7 × 1 = 7
Valence electrons of two chlorine atoms = 7 × 2 = 14

Now the BrCl₂^– has a negative (-1) charge, so we have to add one more electron.

So the total valence electrons = 7 + 14 + 1 = 22

Learn how to find: Bromine valence electrons and Chlorine valence electrons

• Second, find the total electron pairs

We have a total of 22 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 = 22 ÷ 2 = 11

• 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.

Therefore, place bromine in the center and chlorines on either side.

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 11 electron pairs. And two Br — Cl bonds are already marked. So we have to only mark the remaining nine electron pairs as lone pairs on the sketch.

Also remember that bromine is a period 4 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 atoms are chlorines.

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 bromine atom, formal charge = 7 – 6 – ½ (4) = -1

For each chlorine atom, formal charge = 7 – 6 – ½ (2) = 0

Here, the bromine atom has a charge, so mark it on the sketch as follows:

Final structure

The final structure of BrCl₂^– includes a central bromine atom linked to two chlorine atoms through single covalent bonds. In this configuration, the bromine atom utilizes an expanded valence shell to accommodate ten electrons, forming two bonding pairs and retaining three lone pairs. Within this layout, each of the two chlorine atoms successfully reaches a stable octet by maintaining three lone pairs alongside its single shared bond. This arrangement represents the most stable state for the ion because it minimizes formal charges across the structure, with the negative formal charge residing on the central bromine atom. Accordingly, this specific electronic distribution serves as the definitive and most accurate Lewis representation of BrCl₂^–.

To complete the representation, draw square brackets around the entire Lewis structure and place a “-” or “-1” sign as a superscript outside the upper right bracket. This notation signifies that the negative charge is a property of the whole ion.

Next: CF₂S Lewis structure

External video

• How to Draw the Lewis Dot Structure for BrCl2 – – YouTube • Wayne Breslyn

External links

• https://oneclass.com/homework-help/chemistry/7027016-brcl2-lewis-structure.en.html