Lewis Structure, Molecular Geometry, Hybridization, and MO Diagram (HBr Lewis Structure, Molecular Geometry, Hybridization, and MO Diagram)

Bromine belongs to the halogen family, hence hydrogen bromide, or HBr, is a hydrogen halide chemical. Although it is a caustic and harmful chemical, it can also be beneficial in a variety of ways.

It can be used to make a wide range of organic and inorganic bromine compounds. Not only that, but it’s also useful as a catalyst, and scientists hope to use it to build batteries.

HBr is a colourless caustic gas that can be dissolved in alcohols and organic solvents.

It has a melting point of -124.40 degrees Fahrenheit and a density of 3.64 kilogrammes per square metre.

Structure of Lewis

Lewis Structure is a diagrammatic representation of a molecule that includes information about its chemical bonding and electron pair formation.

If we want to understand the internal structure and nature of a specific molecule, we must first study about sigma pi bond formation as well as lone pairs.

Lewis symbols, also known as electron dot structure, are used to determine the electronic configuration of the inner atoms of a molecule or ions.

The Lewis Structure, which uses dots, single, and double lines to represent the nature of bonds, is the first step in determining a chemical compound’s properties, such as hybridization and polarity.

1st step

The total valence electron number is the initial step in determining the Lewis Structure of any given molecule.

The loss of an electron denotes an increase in positive charge, which is why the sign ‘+’ is used. Because the quantity of negatively charged electrons grows as electrons gain, we employ the ‘-‘ sign.

2nd Step

Knowing the number of valence electrons is insufficient for establishing the molecular structure. We must also determine the core atom.

How are we going to do it?

Simple. Simply look at the valency. The atom with the lowest electronegative charge usually has the highest valence and the most bonding sites.

This is said to be the most important atom. Let us continue our discussion.

3rd step

Let us now draw the molecule’s skeletal schematic. We will be able to better grasp the position of the single bonds as a result of this.

4th step

Now that we’ve sketched the molecular skeleton, we must concentrate on the octet fulfilment stage.

Do you know what the “octet rule” is?

The octet rule is primarily concerned with the electrical configuration of noble gases. It describes an atom’s proclivity to have eight electrons in its outermost or valence shell inside a molecule.

While determining the Lewis Structure, we must also consider octet fulfillment—let us begin with the electropositive atoms and work our way to octet completion.

5th step

The penultimate phase in this procedure is to determine whether multiple bonding is required. After we’ve completed octet fulfilment, we’ll need to see if any double or triple bonds are required.

6th step

The skeleton diagram was drawn, single and double bonds were drawn, and the octet rule was confirmed. As we near the end of the process, we must now consider the formal charge notion.

The formula for calculating the formal charge is shown in the diagram above.

As a result, we must determine if the atoms within a given molecule have the lowest formal charge value.

Our Lewis framework will be finished after this is done.

Let’s do the math for HBr now.

Lewis Structure HBr

The molecule HBr, or Hydrogen Bromide, is made up of one hydrogen atom and one bromine atom.

Hydrogen contains only one electronic shell, each with one electron, and only two electrons are required to complete an octet. (It has a helium-like configuration.)

Bromine, with an atomic number of 35, is a member of Group 7, which also includes Chlorine and Fluorine, and hence has seven electrons in its outermost shell.

In HBr, the total number of valence electrons is 1+7=8.

We don’t need to worry about the core atom notion in Hydrogen Bromide because there are only two atoms.

We must now draw the skeleton diagram of HBr according to Step 3 of Lewis Structure creation.

Place a single electron around the Hydrogen atom and seven electrons around the Br atom. We can see that the sketch has achieved octet fulfilment by looking at it.

Keep in mind that, like helium noble gas, hydrogen just requires two atoms to complete its octet structure. Bromine has eight electrons surrounding it, resulting in octet formation and the creation of a single bond.

There is no need to make several bonds in this case. Step 6 will be used to check the formal charge.

Around Bromine, HBr now contains one single bond and six electrons, or three lone pairs. Hydrogen Bromide’s Lewis Structure has been completed.

Let’s move on to the next bonding principle.

Hybridization (HBr)

The chemical HBr (Hydrogen Bromide) possesses sp3 hybridization.

When it comes to the chemical bonding characteristic of a molecule, hybridization is another incredibly important aspect to consider.

While Lewis Structure helps us see how a molecule can appear in 2D, hybridization helps us understand why specific atoms tend to interact in a certain way within a molecule.

So, if we want to learn everything there is to know about HBr, we need to know more than just the Lewis Structure; we also need to know about Hybridization.

Hybridization is the process of atomic orbitals within a molecule overlapping to generate hybrid orbitals. In order to understand HBr, we must consider both Hydrogen and Bromine’s electrical configuration.

It is 1s1 for Hydrogen.

It’s [Ar]4s23d104p5 for Bromine.

As a result, the electrical structure of HBr is as follows:


Bromine has three electron lone pairs around it and one bond with hydrogen as a result.

As a result of this, Br in hydrogen bromide is tetrahedral with a dihedral angle of 1090, resulting in sp3 hybridization.

The s orbital of hydrogen interacts with the 4p orbital of bromine in this reaction.

The sp3 hybrid orbitals point away from the H-Br sigma bond due to a higher degree of effective (stronger) nuclear charge for valence shell electrons at Bromine than at Hydrogen.

Polarity HBr

When it comes to chemical compounds and molecules, polarity is a fascinating idea. Do you realise that polarity can be caused by differences in electronegativity?

This is primarily concerned with the distribution of charges within a molecule: when the positive and negative charges differ, the dipole moment rises, resulting in a net value that renders a chemical compound polar.

Let’s look at HBr and see if it’s polar or non-polar.

Are you aware that the electronegativity of the Bromine atom is higher than that of Hydrogen?

Br has an electronegativity of 2.96, while hydrogen only has a value of 2.2.

As a result of the large electronegativity difference, HBr is classified as a polar molecule. You should also read the polarity of HBr for further information.

This occurs because bromine has a negative charge and hydrogen has a positive charge due to the lone pair in HBr tugging towards bromine.

Molecular Geometry HBr

What is molecular geometry, and how do we know what it is?

Molecular geometry is concerned with using theories to determine the form of a molecule.

The VSEPR model (Valence Shell Electron Pair Repulsion Model Theory) is the most prevalent, and it defines how a molecule will be structured based on electron location and bond formation.

The molecular shape of HBr is straight, with a bond angle of 180 degrees.

Orbital Diagram of a Molecular

HBr is a diatomic molecule with a heterogeneous structure. The chemical bonding notion of molecules is the foundation of the molecular orbital theory.

When we deal with orbitals and energy levels inside a molecule, it is one of the most descriptive and diagrammatic depictions of bonding.

The s and p orbitals interact: the s of hydrogen and the p of bromine.

The p is at a lower energy level than 1s of hydrogen because bromine is more electronegative than hydrogen.

Sigma bonding and sigma-antibonding orbitals result from the overlap.


The Lewis Structure, Hybridization, Polarity, Molecular Geometry, and MO Diagram of the Hydrogen Bromide molecule are discussed in this article.

HBr is a fascinating chemical complex with valuable features, and understanding its internal structure is essential for a better understanding of the molecule as a whole.

Read more: Does Temperature Have an Impact on pH?

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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