Best Overview: Is BrF5 Polar or Nonpolar - Science Education and Tutorials

Bromine pentafluoride with chemical formula BrF5. It is a molecule made of six atoms. All the atoms belong to the halogen family in the periodic table. The students used to ask ” Is BrF5 polar or nonpolar?”, ” BrF5 Lewis structure”, “BrF5 molecular geometry”, “BrF5 bond angle”, and “BrF5 electron geometry”. In this blog post, we are going to discuss them in a detailed manner.

The chemistry of a polar molecule is totally different from the chemistry of a nonpolar molecule. It is not only limited to the chemical characteristics of the molecule. The polarity of the molecule affects the physical properties of the molecule. If you focus on the BrF5 molecule, it has five fluorine atoms and one bromine atom.

All atoms of bromine pentafluoride(BrF5) molecule have high electronegativity values. But fluorine atom has high electronegative value than bromine atom. This makes the five Br-F bonds, much polarise in the BrF5 molecule. Now the question is, “Is BrF5 polar or nonpolar?”.

Bromine pentafluoride(BrF5), is a polar molecule having a square pyramidal molecular geometry shape and an asymmetric charge distribution centering on the central bromine atom. A central bromine atom encompasses a total of five fluorides and forms a lone pair of electrons in the molecule.

As a result, the Bromine pentafluoride(BrF5) molecule must be polar. This pale yellow color, fuming liquid with a pungent odor is primarily utilized as a fluorinating agent in the production of fluorocarbons and as an oxidizer in rocket propellant systems. It is a highly hazardous chemical when inhaled, it creates acute breathing related illness. It is very caustic to the skin.

Metals (implanted in the body) and tissue are both corroded by bromine pentafluoride. It has the ability to speed up the combustion of combustibles. It catalyzed the combustion reaction and used in the metallurgical industry for furnace heating up.

Table of Contents

Preparation of BrF5:

Bromine gas reacted with excess amount of fluorine gas with dilute nitrogen gas at the temperature of 150 degree Celsius gives Bromine pentafluoride.

Br2 + 5F2 (excess) —– 150 degree—–> 2BrF5
formation of bromine pentafluoride from bromine and fluorine

In another method, it can be prepared from bromine trifluoride in the following manner.

BrF3 + F2 — 200 degree—–> BrF5
formation of bromine pentafluoride from bromine trifluoride and excess of fluorine

Bromine trifluoride reacted with excess of fulorine at 200 degree Celsius gives bromine pentafluoride.

Is BrF5 reactive?

Due to the presence of highly electronegative halogens such as bromine and fluorine atoms in its chemical structure, the BrF5 molecule will react with a variety of organic compounds, including liquids like water (H2O).

The chemical BrF5 was determined to be an exceptionally effective oxidizer in case studies conducted in the 1950s and 1960s. It is possessing a very good ability to remove an electron from the atom or molecule.
(i.e. the ability to remove electrons from molecules), which was made possible by the presence of numerous halogens.

BrF5 reaction with water:

Bromine pentafluoride(BrF5) reacted with water and gives hydrofluoric acid and HBrO3.

BrF5 + 3H2O ——–> 5HF + HBrO3
BrF5 reacted with water

Bromine pentafluoride (BrF5) lewis dot structure, molecular geometry, polar or non-polar, bond angle

Bromine pentafluoride has the chemical formula BrF5 and is a pale yellow liquid. As a fluorinating reagent, it is an interhalogen chemical with bromine and fluorine. It is used as a propellent of rockets and fluorinating chemicals. Bromine pentafluoride (BrF5) lewis structure, molecular geometry, polar or non-polar, hybridization, bond angle, and other properties will be discussed in the following manner.

How to draw the BrF5 lewis structure:

BrF5 lewis structure gives basic understanding electron geometry of the molecule. The Lewis structure of BrF5 is a little more complicated than other molecules since some unusual circumstances, such as an enlarged octet structure of BrF5, will arise when sketching it. But don’t worry about it; simply follows the basic rule to get the perfect BrF5 Lewis structure.

One central bromine and five fluorine atoms make up the BrF5 Lewis dot structure. valence electron of atoms represented with the dots in the structure. Bromine located at the center of the molecular structure due to its low electronegative value as compared with fluorine atoms. Bromine has one lone pair that is bonded to five fluorine atoms by five single bonds.

To sketch the BrF5 Lewis structure by following these instructions:

Step-1: Determine the total number of outermost valence shell electrons in the BrF5 molecule. The first step is to figure out how many outermost valence shell electrons there are in the BrF5 Lewis structure. A valence electron is one of an atom’s outermost shell electrons. In the Lewis diagram, it is represented by dots. The central bromine atom of the BrF5 molecule can be represented as follows

Look for the periodic group of each atom in BrF5 to determine its valence electron. Bromine and fluorine are both members of the halogen family, which is the 17th group in the periodic table. Both of them have seven valence electrons in their outermost shell.

Because bromine and fluorine belong to the halogen family group in the periodic table, their valence electrons are both 7.

Total outermost valence shell electron of Fluorine atom in BrF5 = 7
Total outermost valence shell electron of Bromine atom in BrF5= 7
The BrF5 molecule has one central bromine atom and five fluorine atoms. Then the total outermost valence shell electrons can be calculated as follows
∴ Total outermost valence shell electrons available for BrF5 lewis structure( dot structure) = 7 + 7*5 = 42 valence electrons in BrF5
calculation of total valence electron of BrF5 molecule

Step-2: Locate the atom with the least electronegative charge and place it in the center of the BrF5 molecular geometry. In this phase, we’ll select the least electronegative atom in the BrF5 molecule to place in the Lewis structure diagram’s center. In the periodic table, electronegativity increases in order from left to right and decreases in order from top to bottom in periodic groups.

As a result, Fluorine is the first atom in the halogen family group in the periodic table. Bromine comes this in the family group. A bromine atom has a lower electronegative value than a fluorine atom. Furthermore, because fluorine is the most electronegative element in chemistry, it can never be the central atom in a BrF5 Lewis structure diagram. As a result of this, place bromine at the center of the BrF5 Lewis structure, with fluorine uniformly scattered around it the square plane.

Step-3: Use five single bonds (Br-F) to connect the outside and core atoms in the BrF5 molecule. Connect all outside atoms (Fluorine) to the core central atom (Bromine) with five single bonds in this stage.

Count how many outermost valence shell electrons we’ve used so far in the BrF5 structure. Because each bromine atom is connected to a fluorine atom by five single (Br-F) bonds, each connection contains two electrons.

So, from the total of 42 valence electrons available for the BrF5 lewis structure, we employed 10 electrons for 5 single (Br-F) bonds in the BrF5 molecule. There are still 32 valence electrons left in the BrF5 molecule. Where do we need to place them in molecular geometry?

Step-4: Starting with the outer fluorine atoms in the BrF5 molecule, place the remaining valence electrons. We always start inserting valence electrons from the exterior atom first in the Lewis structure diagram. As a result, first, wrap around the leftover valence electrons on each fluorine atom.

To complete its octet, fluorine requires 8 electrons in its outermost valence shell. With the help of a single bond, each fluorine already shares two electrons. Put 6 electrons around each fluorine atom and you’re done with the fluorine molecule in Brf5.

In the BrF5 molecule structure above, we’ve put 30 electrons around the fluorine atoms, represented by a dot. As all fluorine atoms have 8 electrons in their outermost valence shell, each fluorine atom comfortably completes its octet stability in the BrF5 molecule.

Using the above structure, count how many outermost valence shell electrons have been consumed so far. In the BrF5 molecular structure above, 30 electrons are represented as dot structure, whereas 5 single bonds each contain 2 electrons. As an outcome of the calculation, the outermost valence shell electrons are 30 + 10 = 40.

So far, we’ve used 40 of the total 42 outermost valence shell electrons available for the BrF5 Lewis structure. But now the question is, “How to fix the remaining two valence electrons?”. We also have two valence electrons to spare in the BrF5 molecule.

Step-5: Complete central bromine atom octet and use covalent bond if necessary. In the BrF5 lewis structure, bromine is the central atom and it is connected with 5 single bonds (Br-F) to the fluorine atoms. It means it already sharing 10 electrons with the help of 5 single bonds.

So, bromine is obeying the rule of the octet as it has more than 8 electrons around it. The expanded octet state is a chemical term for an atom that has more than 8 electrons surrounding it. Fluorine can never have more than eight electrons surrounding it. Place the two remaining valence electrons around the bromine center atom, which is acting as an extended octet in this case.

What are BrF5 electron and molecular geometry?

BrF5 has a square pyramidal molecular geometry and an octahedral electron geometry, according to the VSEPR theory. Because the core central atom, bromine, has five Br-F bonds with the surrounding fluorine atoms. In the same plane, each F-Br-F bond forms a 90-degree angle. Because four fluorine atoms are in the same plane, they form a square planar shape.

Above that plane, there is one fluorine atom. It maintains the pyramidal-like form after connecting upper fluorine to square planar. The lone pair is located just opposite this top fluorine atom. The one fluorine and lone pair of the electron are just above and below the square plane.

Because of the lone pair of electrons, it gives octahedral electron geometry. But the BrF5 molecular geometry is square pyramidal in nature. It is asymmetrical geometry of BrF5 molecule. That makes, BrF5 molecule is polar.

How to find BrF5 molecular geometry

Determine the number of lone pairs on the BrF5 Lewis structure’s core bromine atom.
We need to figure out how many lone pairs there are on the central bromine atom of the BrF5 Lewis structure because the lone pair on bromine is primarily responsible for the BrF5 molecule geometry distortion.

Use the formula below to find the lone pair on the BrF5 molecule’s center Bromine atom.
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 BrF5 molecule

In the case of BrF5, the center atom, bromine, has seven outermost valence shell electrons and five fluorine atoms connected to it.

As a result of this, L.P(Br) = (7 – 5)/2

The lone pair on the centre bromine atom of the BrF5 electron geometry structure is equal to one.

Determine the number of BrF5 molecular hybridizations.
How to find the hybridization of the BrF5 molecule?. Now we need to figure out what BrF5’s molecular hybridization number is.

The formula of BrF5 molecular hybridization is as follows:
No. Hyb = N.A(Br-F) + L.P(Br)
No. Hy= the number of hybridizations
Number of Br-F bonds = N.A (Br-F)
Lone pair on the central bromine atom = L.P(Br)
Calculation for hybridization number for BrF5 molecule

Bromine, then, is a center atom with five fluorine atoms linked to it and one lone pair in the BrF5 molecule. Then the number of hybridization (No. Hyb) can be calculated as follows

No. Hyb = 5+1 =6

No of hybridization for BrF5 molecule is six. one S orbital, three p orbitals, and two d orbitals combine together formed the sp3d2 hybridization.

3. Use VSEPR theory to determine BrF5 molecular geometry shape

When the VSEPR theory is utilized to calculate the shape of BrF5 molecule, the AXN approach is typically used.

The AXN notation is as follows:
The center bromine atom in the BrF5 molecule is denoted by the letter A.
The bound pairs (Br-F) of electrons to the core atom are represented by X.
The lone pairs of electrons on the center bromine atom are denoted by the letter N.
Notation for BrF5 molecular geometry

We know bromine is the center atom with 5 bound (Br-F) pairs of electrons and one lone pair. because of the BrF5 Lewis structure. BrF5 has the general molecular geometry formula AX5N1.

If the molecule has an AX5N1 generic formula, the molecular geometry will be square pyramidal, and the electron geometry will be octahedral, according to the VSEPR theory.

How to calculate the formal charge in BrF5 Lewis Structure?

The formal charge on the bromine central atom of the BrF5 molecule often represents the actual charge on that bromine central atom. The formal charge will be found on the central bromine atom of the BrF5 Lewis dot structure in the following calculation.

To calculate the formal charge on central bromine atom of BrF5 molecule by using the following formula:
The formal charge on Bromine atom of BrF5 molecule= (V. E(Br)– l.E(Br) – 1/2(B.E))
V.E (Br) = Valence electron in bromine atom of BrF5 molecule
I.E(Br) = Lone pairs of an electron in bromine atom of BrF5 molecule.
B.E = Bond pair electron in Br atom of BrF5 molecule
calculation of formal charge on bromine atom in BrF5 molecule

We have 7 valence electrons, 2 lone pair electrons, and 10 bonding electrons in the bromine central atom (5 single bonds attached to fluorine) of the BrF5 molecule. Now put these value of the bromine atom in the above formula

Formal charge on Bromine atom of BrF5 molecule = (7 – 2 -(10/2)) =0

The formal charge on central bromine atom of BrF5 lewis structure is zero.

Lewis structure of some other related post in this blog. See more detail by clicking on it, H2O, BeCl2, SF4, NH3, XeF4, BF3, and CH2Cl2 molecules.

Geometrical Properties of Bromine pentafluoride

BrF5 is the type of interhalogen compound with fluorine and bromine atom has the ability to react with water and form products.
BrF5 is a potent oxidant and fluorinating agent with serious consequences.
The molecular mass of BrF5 is 174.894 g/mol.
BrF5 has a boiling point of 40.25 degrees Celsius and a melting point of 61.30 degrees Celsius.
BrF5 density is 2,48 g/cm³
BrF5 vapor pressure is 328 mm Hg.
Refractivity of BrF5 is 16.24 m³·mol⁻¹
Polarizability of BrF5 is 6.94 Å³

Molecular Geometrical Properties table:

Name of interhalogen Molecule	Bromine pentafluoride
Chemical formula of interhalogen compound	BrF5
Molecular geometry of BrF5 molecule	Square pyramidal
Electron geometry of BrF5 molecule	Octahedral
Molecular Hybridization of BrF5	Sp³d²
Bond angle F-Br-F	90º
Total Valence electron for BrF5 Lewis structure	42
The formal charge on the bromine atom of BrF5	0

Is BrF5 Polar or Nonpolar

Because of its square pyramidal molecular structure, asymmetric charge distribution, and 90° bong angle, bromine pentafluoride (BrF5) is a polar molecule. A core bromine atom is surrounded by five fluorides and a pair of electrons in this molecule. To better clarify your confusion, look at the image below. The bond angle of the BrF3 molecule is 86.2 degrees, which is lower than that of BrF5.

Because of its asymmetric shape of the BrF5 molecule, BrF5 is a polar molecule because it creates unequal charge distribution surrounding atoms, making it difficult to cancel out the dipole along with five Br-F bonds with them, resulting in a net dipole moment for it. As a result, BrF5’s overall structure is polar.

Any molecule with a net dipole moment goes into the polar molecule category, while those with zero dipole moments go into the nonpolar molecule category, like BeCl2. Because lone pair and bond pair of BrF5 molecule repel each other, the presence of a lone pair on the central bromine atom in the BrF5 molecule causes deformation in its molecular geometry.

As a result of this, a negative charge distribution of the BrF5 molecule is not evenly distributed across the molecule. This makes the molecule more polar in nature. Also, whether a BrF5 molecule is polar or non-polar is determined by the electronegativity difference between the atoms. The greater the difference in electronegativity between two atoms, the stronger the polarity between them.

Bromine has an electronegativity of 2.96, while fluorine has an electronegativity of 3.98. The electronegativity difference between them is more than 0.5, indicating that they form a polar covalent bond(Br-F). If the difference in electronegativity between the atoms is higher than 0.5 on the Pauling scale, they are said to be polar. If the difference in electronegativity between atoms is lower than 0.5 on the Pauling scale, the molecule is said to be nonpolar.

Bromine’s lower electronegativity than fluorine is usually owing to the number of layers of electrons protecting the nucleus or central in bromine(Br) atom, lowering the average pullover of its valence electrons. Meanwhile, when internal electrons are considered, (F) Fluorine does not have a large number of layers, which could contribute to its shielding effect, proving that it has more electronegativity value than Br or bromine (in fact, Fluorine atom has the highest electronegativity value than of any other atomic element in the periodic table!).

Conclusion

Bromine pentafluoride(BrF5) is made by a central bromine atom with surrounding five fluorine atoms in square pyramidal geometry. The Lewis structure of the BrF5 molecule gives information about the bond pairing and lone pair of the molecule. Bromine pentafluoride(BrF5) electron geometry is octahedral in nature. BrF5 is extensively used in oxidizing and rocket propellent.

If you have any queries and doubts about this article, please leave a message in the comment section. We will get back to you as soon as possible.

FAQ on “Is BrF5 polar or nonpolar ?”

Why BrF5 is a polar molecule?

Because the negative charge is not distributed uniformly throughout the molecule, BrF5 is a polar molecule. Bromine (Br) possesses seven valence electrons since it is a halogen.