NaBr Molecular Geometry - Science Education and Tutorials

Q: What is the molecular notation for NaBr molecule?

NaBr molecular notation is AX1N3.

Sodium bromide(NaBr) has the composition of one bromine and one sodium atom. What is the molecular geometry of sodium bromide?. Drawing and predicting the NaBr molecular geometry is very easy by following the given method. Here in this post, we described step by step to construct NaBr molecular geometry. Bromine and sodium come from the 17th and 1st family groups in the periodic table. Bromine and sodium have seven and one valence electrons respectively.

Table of Contents

Key Points To Consider When drawing The NaBr Molecular Geometry

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

The NaBr molecular geometry is a diagram that illustrates the number of valence electrons and bond electron pairs in the NaBr molecule in a specific geometric manner. The geometry of the NaBr molecule ion 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 NaBr 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 one Na-Br single bonds (dipole moment properties of the NaBr molecular geometry). One sodium-bromine single bonds in the sodium bromide(NaBr), for example, are polarised toward the more electronegative value bromine atom, and because (Na-Br) single bonds have the same size and polarity, their sum is nonzero due to the NaBr molecule’s bond dipole moment due to pulling the electron cloud to the two side of linear geometry, and the NaBr molecule is classified as a polar molecule.

The molecule of sodium bromide(with linear shape NaBr molecular geometry) is tilted at 180 degrees bond angle of Na-Br. It has a difference in electronegativity values between bromine and sodium atoms, with bromine’s pull the electron cloud being greater than sodium’s. But bond polarity of Na-Br is not canceled to each other in the linear geometry. As a result, it has a nonzero permanent dipole moment in its molecular structure. The NaBr molecule has a nonzero dipole moment due to an unequal charge distribution of negative and positive charges in the linear geometry.

Overview: NaBr electron and molecular geometry

According to the VSEPR theory, the NaBr molecule ion possesses linear molecular geometry. Because the center atom, bromine, has one Na-Br single bond with the one sodium atom surrounding it. The Na-Br bond angle is 180 degrees in the linear NaBr molecular geometry. The NaBr molecule has a linear geometry shape because it contains one sodium atom in the linear and four corners with four lone pairs of electrons.

There is one Na-Br single bond at the NaBr molecular geometry. After linking the one sodium atom and four lone pairs of electrons on the bromine atom (as bromide ion) in the linear form, it maintains the linear-shaped structure. In the NaBr molecular geometry, the Na-Br single bond has stayed in the one terminal and four lone pairs of electrons on the bromine atom of the linear molecule.

The center bromine atom of NaBr has four lone pairs of electrons, resulting in linear NaBr electron geometry. However, the molecular geometry of NaBr looks linear-shaped and has four lone pairs of electrons on the bromine of the NaBr geometry. It’s the NaBr molecule’s slight asymmetrical geometry. As a result, the NaBr molecule is more polar.

How to find NaBr hybridization and molecular geometry

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

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

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

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

For instance of NaBr, the central atom, bromine, has seven electrons in its outermost valence shell, one Na-Br single bond connection. This gives a total of one connection.

As a result of this, L.P(Br) = (8 –0)=8

The lone pair of electrons in the bromine atom of the NaBr molecule is four.

Calculating lone pair of electrons on sodium in the NaBr geometry:

Finding lone pair of electrons for the terminal sodium atom is similar to the central bromine atom. We use the following formula as given below

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

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

For instance of NaBr, their terminal atoms, sodium, have one electron in its outermost valence shell, one Na-Br single bond connection. This gives a total of one Na-Br single bond connection. But we are considering only one connection for the calculation.

As a result of this, L.P(Na) = (0 –0)=0

The lone pair of electrons in the sodium atom of the NaBr molecule is zero. One sodium atom is connected with the central bromine atom.

In the NaBr electron geometry structure, the lone pairs on the central bromine atom are four, lone pairs of electrons in the sodium atom have zero. One sodium atom has no lone pairs of electrons.

It means there are four lone pairs of electrons in the core bromine atom (as bromide ion). Four lone pair of electrons on the central bromine atom is responsible for the linear nature of NaBr molecular geometry. But in the structure sodium atom is polarised sidewise in their linear geometry.

The four lone pairs of electrons are placed at another side of the NaBr geometry. Because the sodium atom is a lower electronegative value as compared with other atoms in the NaBr molecule. One sodium atom is polarized towards the sidewise in the NaBr structure.

But in reality, the NaBr has four lone pairs of electrons in its structure. This makes the NaBr more asymmetrical in the structure of the molecule. Because there is electric repulsion between bond pairs and lone pairs.

But some sort of interaction is there between sodium empty hole and lone pairs of electrons of bromine of another NaBr molecule. Here, sodium of one molecule acts as an acceptor and bromine of another molecule as a donor. This is called sodium bonding between the two NaBr molecules. This is one of the main intermolecular forces in NaBr.

But in the central, bromine atom has four lone pairs of electrons and these lone pair electrons are placed in the four corners of the tetrahedral.

Calculate the number of molecular hybridizations of the NaBr molecule

What is NaBr 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

NaBr molecule is made of one bromine and a sodium atom. The sodium and bromine atoms have s and p orbitals. But sodium atom has only s orbital in the ground state. Sodium comes as the first element in the periodic table. The bromine atom also belongs to the halogen family group. But it falls as the third element in the periodic table.

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

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

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

In the NaBr molecule, bromine is a core central atom with one sodium atom connected to it. It has fourlone pairs of electrons on bromine (as a bromide ion). The number of NaBr hybridizations (No. Hyb of NaBr) can then be estimated using the formula below.

No. Hyb of NaBr= 4+0=4

The NaBr molecule ion hybridization is four. The bromine and sodium atoms have s and p orbitals. The sp3 hybridization of the NaBr molecule is formed when one s orbital and three p orbitals join together to form the NaBr molecular orbital.

Molecular Geometry Notation for NaBr Molecule :

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

The AXN notation of NaBr molecule is as follows:
The central bromine atom in the NaBr molecule is denoted by the letter A.
The bound pairs (one Na-Br 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 NaBr molecular geometry

We know that bromine is the core atom, with no electron pair bound (one ionic bond Na-Br) and four lone pairs of electrons. The general molecular geometry formula for NaBr is AN4.

According to the VSEPR theory, if the NaBr molecule ion has an AN4 generic formula, the molecular geometry and electron geometry will both be linear-shaped forms.

Name of Molecule	Sodium bromide
Chemical molecular formula	NaBr
Molecular geometry of NaBr	linear
Electron geometry of NaBr	linear
Hybridization of NaBr	sp3
Bond angle (Na-Br)	180º degree
Total Valence electron for NaBr	8
The formal charge of NaBr on bromine	0

Summary:

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