BrF3 Molecular Geometry - Science Education and Tutorials

Q: What is the molecular notation for BrF3 molecule?

BrF3 molecular notation is AX3N2.

Trifluoro bromine or bromine trifluoride(BrF3) has the composition of one bromine and three fluorine atoms. What is the molecular geometry of bromine trifluoride?. Drawing and predicting the BrF3 molecular geometry is very easy by following the given method. Here in this post, we described step by step to construct BrF3 molecular geometry. Bromine and fluorine come from the 17th family group in the periodic table. Bromine or fluorine has seven valence electrons.

Table of Contents

Key Points To Consider When drawing The BrF3 Molecular Geometry

A three-step approach for drawing the BrF3 molecular can be used. The first step is to sketch the molecular geometry of the BrF3 molecule, to calculate the lone pairs of the electron in the central bromine atom; the second step is to calculate the BrF3 hybridization, and the third step is to give perfect notation for the BrF3 molecular geometry.

The BrF3 molecular geometry is a diagram that illustrates the number of valence electrons and bond electron pairs in the BrF3 molecule in a specific geometric manner. The geometry of the BrF3 molecule can then be predicted using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory) and molecular hybridization theory, which states that molecules will choose the BrF3 geometrical shape in which the electrons have from one another in the specific molecular structure.

Finally, you must add their bond polarities characteristics to compute the strength of the three Br-F bonds (dipole moment properties of the BrF3 molecular geometry). The bromine-fluorine and three bromine-fluorine bonds in the bromine trifluoride(BrF3), for example, are polarised toward the more electronegative value fluorine atoms, and because all three (Br-F) bonds have the same size and polarity, their sum is nonzero due to the BrF3 molecule’s bond dipole moment due to pulling the electron cloud to the downside in the trigonal bipyramidal geometry, and the BrF3 molecule is classified as a polar molecule.

The molecule of bromine trifluoride(with trigonal bipyramidal shape BrF3 molecular geometry) is tilted at 86.2 degrees bond angle of F-Br-F. It has a difference in electronegativity values between bromine and fluorine atoms, with fluorine’s pull the electron cloud being greater than bromine’s. But bond polarity of Br-F is not canceled to each other in the trigonal bipyramidal geometry. As a result, it has a permanent dipole moment in its molecular structure. The BrF3 molecule has a dipole moment due to an unequal charge distribution of negative and positive charges.

Overview: BrF3 electron and molecular geometry

According to the VSEPR theory, the BrF3 molecule possesses trigonal bipyramidal molecular geometry. Because the center atom, bromine, has three Br-F bonds with the three fluorine atoms surrounding it. The F-Br-F bond angle is 86.2 degrees in the trigonal bipyramidal BrF3 molecular geometry. The BrF3 molecule has a trigonal geometry shape because it contains three fluorine atoms.

There are three Br-F bonds at the BrF3 molecular geometry. After linking the three fluorine atoms and two lone pairs of electrons in the trigonal bipyramidal form, it maintains the distorted T-shaped structure. In the BrF3 molecular geometry, the Br-F bonds have stayed in the three terminals and two lone pairs of electrons on the bromine atom of the trigonal bipyramidal molecule.

The center bromine atom of BrF3 has two lone pairs of electrons, resulting in trigonal bipyramidal BrF3 electron geometry. However, the molecular geometry of BrF3 looks distorted T-shaped and two lone pairs of electrons on the bromine of the BrF3 geometry. It’s the BrF3 molecule’s symmetrical geometry. As a result, the BrF3 molecule is polar.

How to find BrF3 hybridization and molecular geometry

Calculating lone pairs of electrons on bromine in the BrF3 geometry:

1.Determine the number of lone pairs of electrons in the core bromine atom of the BrF3 Lewis structure. Because the lone pairs of electrons on the bromine atom are mostly responsible for the BrF3 molecule geometry distortion, we need to calculate out how many there are on the central bromine atom of the BrF3 Lewis structure.

Use the formula below to find the lone pair on the bromine atom of the BrF3 molecule.
L.P(Br) = V.E(Br) – N.A(Br-F)/2

Lone pair on the central bromine atom = L.P(Br)
The core central bromine atom’s valence electron = V.E(Br)
Number of Br-F bonds = N.A (Br-F)
calculation for bromine atom lone pair in BrF3 molecule.

For instance of BrF3, the central atom, bromine, has seven electrons in its outermost valence shell, three Br-F bond connections. This gives a total of three connections.

As a result of this, L.P(Br) = (7 –3)/2=2

The lone pairs of electrons in the bromine atom of the BrF3 molecule are two.

Calculating lone pairs of electrons on fluorine in the BrF3 geometry:

Use the formula below to find the lone pair on the fluorine atom of the BrF3 molecule.
L.P(F) = V.E(F) – N.A(Br-F)

Lone pair on the terminal fluorine atom = L.P(F)
Terminal fluorine atom’s valence electron = V.E(F)
Number of Br-F bonds = N.A ( Br-F)
calculation for fluorine atom lone pair in BrF3 molecule.

For instance of BrF3, three terminal atoms, fluorine, have seven electrons in its outermost valence shell, one Br-F bond connection. This gives a total of three Br-F bond connections. But we are considering only one connection for the calculation.

As a result of this, L.P(Br) = (7 –1)=6

The lone pairs of electrons in the fluorine atom of the BrF3 molecule are six. Three fluorine atoms are connected with the central bromine atom.

In the BrF3 electron geometry structure, the lone pair on the central bromine atom is two. lone pairs of electrons in the fluorine atom have six. Three fluorine atoms have 18 lone pairs of electrons.

It means there are two lone pairs of electrons in the core bromine atom. Two lone pair of electrons on the central bromine atom is responsible for the trigonal bipyramidal nature of BrF3 molecular geometry. But in the structure fluorine atoms are polarised sidewise in their geometry.

The two lone pairs of electrons are placed at another side of the BrF3 geometry. Because the bromine atom is a lower electronegative value as compared with other atoms in the BrF3 molecule. Three fluorine atoms are polarized towards the sidewise in the BrF3 structure.

But in reality, the BrF3 has two lone pairs of electrons in its structure. This makes the BrF3 more irregular structure of the molecule. Because there is electric repulsion between bond pairs and lone pairs. But some sort of interaction is there between fluorine lone pairs and bond pairs. But it is negligible.

Calculate the number of molecular hybridizations of the BrF3 molecule

What is BrF3 hybridization? This is a very fundamental question in the field of molecular chemistry. All the molecules are made of atoms. In chemistry, atoms are the fundamental particles. There are four different types of orbitals in chemistry. They are named s, p, d, and f orbitals.

The entire periodic table arrangement is based on these orbital theories. Atoms in the periodic table are classified as follows:

s- block elements
p- block elements
d-block elements
f-block elements
Atoms are classified in the periodic table

BrF3 molecule is made of one bromine, three fluorine atoms. The fluorine and bromine atoms have s and p orbitals. Fluorine comes as the first element from the halogen family in the periodic table. The bromine atom also belongs to the same family group. But it falls as the third element in the periodic table.

When these atoms combine to form the BrF3 molecule, its atomic orbitals mixed and form unique molecular orbitals due to hybridization.

How do you find the BrF3 molecule’s hybridization? We must now determine the molecular hybridization number of BrF3.

The formula of BrF3 molecular hybridization is as follows:
No. Hyb of BrF3= N.A(Br-F bonds) + L.P(Br)
No. Hy of BrF3= the number of hybridizations of BrF3
Number of Br-F bonds = N.A (Br-F bonds)
Lone pair on the central bromine atom = L.P(Br)
Calculation for hybridization number for BrF3 molecule

In the BrF3 molecule, bromine is a core central atom with three fluorine atoms connected to it. It has two lone pairs of electrons on bromine. The number of BrF3 hybridizations (No. Hyb of BrF3) can then be estimated using the formula below.

No. Hyb of BrF3= 3+2 =5

The BrF3 molecule hybridization is five. The bromine and fluorine atoms have s and p orbitals. The sp3d hybridization of the BrF3 molecule is formed when one S orbital, three p orbitals, and one d orbital join together to form the BrF3 molecular orbital.

Molecular Geometry Notation for BrF3 Molecule :

Determine the form of BrF3 molecular geometry using VSEPR theory. The AXN technique is commonly used when the VSEPR theory is used to calculate the shape of the BrF3 molecule.

The AXN notation of BrF3 molecule is as follows:
The central bromine atom in the BrF3 molecule is denoted by the letter A.
The bound pairs (three Br-F bonds) of electrons to the core bromine atom are represented by X.
The lone pairs of electrons on the central bromine atom are denoted by the letter N.
Notation for BrF3 molecular geometry

We know that bromine is the core atom, with three electron pairs bound (three Br-F) and two lone pairs of electrons. The general molecular geometry formula for BrF3 is AX3N2.

According to the VSEPR theory, if the BrF3 molecule has an AX3N2 generic formula, the molecular geometry and electron geometry will both trigonal bipyramidal forms.

Name of Molecule	Bromine trifluoride
Chemical molecular formula	BrF3
Molecular geometry of BrF3	Trigonal bipyramidal
Electron geometry of BrF3	Trigonal bipyramidal
Hybridization of BrF3	sp3d
Bond angle (F-Br-F)	86.2º degree
Total Valence electron for BrF3	28
The formal charge of BrF3 on bromine	0

Summary:

In this post, we discussed the method to construct BrF3 molecular geometry, the method to find the lone pairs of electrons in the central bromine atom, BrF3 hybridization, and BrF3 molecular notation. Need to remember that, if you follow the above-said method, you can construct the BrF3 molecular structure very easily.