BrF4- Lewis Structure & Characteristics: 11 Complete Facts


BrF4is tetrafluorobromate(lll) anion. This is an inert anion. Let us discuss some important facts related to it.

The Lewis structure of BrF4contains Bromine, as the central atom and four Fluorine atoms surrounding it. In BrF4, Bromine is attached to four Fluorine atoms by single bonds. There are two lone pairs present on Bromine atom and also a formal charge of -1

Lewis structure of BrF4consists of bromine and four fluorine atoms. Let us discuss shape, hybridization, bond angle, formal charge and some more characteristics of BrF4.

How to draw BrF4 Lewis structure

BrF4is a square planar anion. Let us draw Lewis structure of BrF4 by following five simple steps.

Step 1: Count the total valence electrons of BrF4

Both Bromine and Fluorine belong to group 17. Thus, Br and F contains 7 electrons in their valence shell. One more electron is added due to the -1 charge. The total valence of BrF4are, BrF4 = 7 + 4*7 + 1 = 36. Thus, BrF4has total valence electrons of 36.

Step 2: Decide the central atom of BrF4

The central atom in the Lewis structure is the least electronegative atom. Bromine is the less electronegative atom than Fluorine. So, Bromine will occupy the central position and four Fluorine atom will surround it.

Step 3: Put an electron pair between the atoms to represent a chemical bond

BrF4has 36 valence electrons. Out of 36 electrons, 32 electrons are used up in forming single bonds between Bromine and four Fluorine atoms.

Step 4: Complete the octet of the outer atoms

Complete the octet of the outer fluorine atoms. Put the remaining 4 electrons on the central Bromine atom.

Step 5: Formal charge calculation

Now, we will calculate the formal charge for each atom in BrF4 to check the stability of Lewis structure.

Each atom has a minimum formal charge in the Lewis structure of BrF4. Thus, this is the stable structure for BrF4.

brf4- lewis structure
Lewis structure of BrF4

BrF4Lewis structure shape

We can decide the shape of the molecule by VSEPR theory. To decide the shape of molecule, VSEPR theory takes into consideration bond pairs and lone pairs.

The shape of BrF4is square planar because the central atom Bromine is sp3d2 hybridized. The central atom Br has four bond pairs and two lone pairs present on it. The electron pair geometry of BrF4 is octahedral.

BrF4Lewis structure formal charge

Formal charge is the charge that would on an atom in a molecule if electrons are shared equally between the atoms. Let us discuss the formal charge of BrF4 below.

The formal charge of BrF4molecule is -1. The Formula to calculate formal charge for BrF4, Formal charge = valence electrons – ½*bonding electrons – number of non-bonding electrons on an atom.

The Formal charge for bromine and fluorine are as follows –

  • The central Br atom = 7 – 1/2*8 – 4 = -1
  • The charge on each F atom = 7 – ½*2 – 6 = 0

So, the formal charge on BrF4molecule is -1

BrF4Lewis structure angle

The bond angle is the angle made by the two covalent bonds from the same atom. Let us discuss the bond angle below.

Bond angle of BrF4, F-Br-F is 90 degrees with square planar shape. The bond angle depends on hybridization and number of bond pairs and lone pair interactions.

BrF4Lewis structure octet rule

Tendency of atoms to complete its valence shell with eight electrons is called as Octet rule. We will discuss here for BrF4.

In BrF4, each Fluorine atom has complete octet of electrons. Bromine atom has more than 8 electrons (12 electrons) around it in the Lewis structure. Bromine has an expanded octet.

BrF4Lewis structure lone pairs

Lone pairs are the electron pairs present on an atom ch are not involved in bonding. We will discuss here whether BrF4ion contains lone pairs.

There are fourteen lone pairs present in the Lewis structure of BrF4. There are 2 lone pairs on the central Bromine atom and 3 lone pairs on each fluorine atom.

Number of Lone pairs present on Br and F in BrF4anion is as follows –

  • Bromine atom = 2
  • Each of the four Fluorine atoms = 3
  • Number of lone pairs present in BrF4ion= 2 + 4*3= 14 lone pairs
  • Thus, BrF4 has 14 lone pairs in the Lewis structure.

BrF4valence electrons

The electrons present in the outermost shell of an atom are called valence electrons. Let us discuss the valence electrons in BrF4 below.

There are 36 valence electrons present inn the Lewis structure of BrF4. Both Br and F belong to group 17 of the periodic table. Thus, Br and F have 7 electrons in their valence shell.

The valence electrons of each atom in the Lewis structure of BrF4 is as follows –

  • Electrons present in valence shell of Bromine= 7
  • Electrons present in valence shell of Fluorine= 7
  • One more electron due to -1 charge = 1
  • Thus, total valence electron in BrF4= 7 + 4*7+1= 36 electrons

BrF4hybridization

Hybridization is the process in which atomic orbitals of same element mix to form the hybrid orbitals of lower energies suitable to form bonds. Let us discuss for BrF4.

Hybridization of central atom Bromine in BrF4is sp3d2. Hybridization can be found out by using the formula, Hybridization number = number of bonds + lone pairs on the central atom. Thus, Hybridization of central atom Br = 4 + 2 = 6(sp3d2).

Is BrF4 polar or nonpolar?

A polar molecule contains partially charged regions. Non-polar molecule does not contain partially charged regions. Let us discuss for BrF4 below.

BrF4is a non-polar anion because it does not contain partially charged regions. Electrons are shared equally between the bonded atoms in non-polar molecule. Net dipole moment of BrF4 is zero. This makes BrF4 non-polar anion.

Is BrF4electrolyte?

An electrolyte is a substance which can conduct electric current when dissolved in water. We will discuss here for BrF4.

BrF4 is an electrolyte because it can conduct electric current in water. Electrolytes are electrically charged species. 

Is BrF4 Ionic or covalent?

Covalent bond is formed between two non-metals. Ionic bond is the bond formed between a metal and a non-metal by transfer of electron(s). Let us discuss for BrF4.

BrF4 is a covalent compound because the bonds between Bromine and Fluorine is formed by sharing of electrons. Both Br and F are non-metals. The electronegativity difference between is lesser than 2.0. It consists of four single covalent bonds between Bromine and four Fluorine atoms.

Conclusion:

BrF4is tetrafluorobromate(lll) anion. It has a square planar shape. The bond angle in BrF4 is 90 degrees.

Sonali Jham

Hi...I am Sonali Jham. I have done my Post-Graduation in Chemistry and also completed B. Ed. I am a Teacher and a Dietician by profession. My hobby is reading and painting. Let's connect through LinkedIn-https://www.linkedin.com/in/sonali-jham-5110a4212

Lewis structure