BrF5 Lewis structure

BrF₅ (bromine pentafluoride) has one bromine atom and five fluorine atoms.

In the BrF₅ Lewis structure, there are five single bonds around the bromine atom, with five fluorine atoms attached to it. Each fluorine atom has three lone pairs, and the bromine atom has one lone pair.

Alternative method: Lewis structure of BrF₅

Rough sketch

• First, determine the total number of valence electrons

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

Hence, both bromine and fluorine have seven valence electrons.

Since BrF₅ has one bromine atom and five fluorine atoms, so…

Valence electrons of one bromine atom = 7 × 1 = 7
Valence electrons of five fluorine atoms = 7 × 5 = 35

And the total valence electrons = 7 + 35 = 42

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

• Second, find the total electron pairs

We have a total of 42 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 = 42 ÷ 2 = 21

• Third, determine the central atom

We have to place the least electronegative atom at the center.

Since bromine is less electronegative than fluorine, assume that the central atom is bromine.

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

• And finally, draw the rough sketch

Lone pair

Here, we have a total of 21 electron pairs. And five Br — F bonds are already marked. So we have to only mark the remaining sixteen 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 fluorine is a period 2 element, so it can not keep more than 8 electrons in its last shell.

Always start to mark the lone pairs from outside atoms. Here, the outside atoms are fluorines.

So for each fluorine, there are three lone pairs, and for bromine, there is one lone pair.

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 – 2 – ½ (10) = 0

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

Here, both bromine and fluorine atoms do not have charges, so no need to mark the charges.

Final structure

The final structure of BrF₅ comprises a central bromine atom connected to five fluorine atoms through single covalent bonds. In this configuration, the bromine atom utilizes an expanded valence shell to accommodate twelve electrons, consisting of five bonding pairs and one lone pair. Within this layout, each of the five fluorine atoms fulfills the octet rule by maintaining three lone pairs alongside its single shared bond. This arrangement represents the most stable state for the molecule because it results in a formal charge of zero for every atom involved, including the central bromine and all five fluorine atoms. Consequently, this specific electronic distribution serves as the definitive and most accurate Lewis representation of bromine pentafluoride.

Next: NCl₃ Lewis structure

External video

• How to Draw the Lewis Dot Structure for BrF5: Bromine pentafluoride – YouTube • Wayne Breslyn

External links

• https://topblogtenz.com/bromine-pentafluoride-brf5-lewis-dot-structure-and-molecular-geometry/
• https://techiescientist.com/brf5-lewis-structure/
• https://www.thegeoexchange.org/chemistry/bonding/Lewis-Structures/BrF5-lewis-structure.html
• https://lambdageeks.com/brf5-lewis-structure/
• https://geometryofmolecules.com/brf5-lewis-structure-molecular-structure-hybridization-bond-angle-and-shape/
• https://sciedutut.com/brf5-lewis-structure/