CH2Br2 Molecular Geometry - Science Education and Tutorials

Q: What is the molecular notation for CH2Br2 molecule?

CH2Br2 molecular notation is AX4.

Dibromomethane(CH2Br2) has the composition of one carbon, two bromine, and two hydrogen atoms. What is the molecular geometry of dibromomethane?. Drawing and predicting the CH2Br2 molecular geometry is very easy by following the given method. Here in this post, we described step by step to construct CH2Br2 molecular geometry. Hydrogen, bromine, and carbon come from the1st, 17th, and 14th family groups in the periodic table. Hydrogen, bromine, and carbon have one, seven, and four valence electrons respectively.

Table of Contents

Key Points To Consider When drawing The CH2Br2 Molecular Geometry

A three-step approach for drawing the CH2Br2 molecular can be used. The first step is to sketch the molecular geometry of the CH2Br2 molecule, to calculate the lone pairs of the electron in the central carbon atom; the second step is to calculate the CH2Br2 hybridization, and the third step is to give perfect notation for the CH2Br2 molecular geometry.

The CH2Br2 molecular geometry is a diagram that illustrates the number of valence electrons and bond electron pairs in the CH2Br2 molecule in a specific geometric manner. The geometry of the CH2Br2 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 CH2Br2 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 C-Br bond (dipole moment properties of the CH2Br2 molecular geometry). The carbon-bromine bonds in the dibromomethane molecule(CH2Br2), for example, are polarised toward the more electronegative value bromine atom, and because all (C-H and C-Br) bonds have the same size and polarity, their sum is non zero due to the CH2Br2 molecule’s bond dipole moment, and the CH2Br2 molecule is classified as a polar molecule.

The molecule of dibromomethane (with tetrahedral shape CH2Br2 molecular geometry) is tilted at 112.5(H-C-H) and 113.4(Br-C-Br) degrees. It has a difference in electronegativity values between bromine and carbon atoms, with bromine’s pull the electron cloud being greater than carbon’s. As a result, it has a permanent dipole moment in its molecular structure. The CH2Br2 molecule has a dipole moment due to an unequal charge distribution of negative and positive charges.

Overview: CH2Br2 electron and molecular geometry

According to the VSEPR theory, CH2Br2 possesses tetrahedral molecular geometry and CH4-like electron geometry. Because the center atom, carbon, has two C-H and C-Br bonds with the hydrogen and bromine atoms surrounding it. The H-C-H and Br-C-Br bond angles generate 112.5 and 113.4 degrees in the tetrahedral molecular geometry respectively. The CH2Br2 molecule has a tetrahedral geometry shape because it contains two bromine and two hydrogen atoms.

There are two C-H and two C-Br bonds at the CH2Br2 molecular geometry. After linking the two hydrogens and two bromine atoms in the tetrahedral form, it maintains the tetrahedral-like structure. In the CH2Br2 molecular geometry, the C-Br and C-H bonds have stayed in the four terminals of the tetrahedral molecule.

The center carbon atom of CH2Br2 has no lone pair of electrons, resulting in tetrahedral electron geometry. However, the molecular geometry of CH2Br2 looks like a tetrahedral and no lone pair out of the plane. It’s the CH2Br2 molecule’s asymmetrical geometry. As a result, the CH2Br2 molecule is polar.

How to find CH2Br2 hybridization and molecular geometry

Calculating lone pairs of electron on carbon in the CH2Br2 molecular geometry:

1.Determine the number of lone pairs on the core be an atom of the CH2Br2 Lewis structure. Because the lone pairs on carbon are mostly responsible for the CH2Br2 molecule geometry distortion, we need to calculate out how many there are on the central carbon atom of the Lewis structure.

Use the formula below to find the lone pair on the carbon atom of the CH2Br2 molecule.
L.P(C) = V.E(C) – N.A(C-H and C-Br)/2

Lone pair on the central carbon atom = L.P(C)
The core central carbon atom’s valence electron = V.E(C)
Number of C-H and C-Br bonds = N.A (C-H and C-Br)
calculation for carbon atom lone pair in CH2Br2 molecule

For instance of CH2Br2, the central atom, carbon, has four electrons in its outermost valence shell, two C-H, and two C-Br bond connections.

As a result of this, L.P(C) = (4 –4)/2=0

In the CH2Br2 electron geometry structure, the lone pair on the central carbon atom is zero. It means there is no lone pair in the core carbon atom. These lone pair on the central carbon atom is responsible for the CH2Br2 molecular geometry distortion.

If you imagine, there is no lone pair on the carbon atom of the CH2Br2 molecule. Then, no electronic repulsion of C-Br and C-H bonds pair in the CH2Br2. That gives stable tetrahedral geometry.

But in reality, the CH2Br2 molecule undergoes distortion in its geometry due to the polarity of two bromine atoms in the tetrahedral geometry. This leads to tetrahedral geometry for the CH2Br2 molecule.

Calculate the number of molecular hybridizations of CH2Br2 molecule

What is CH2Br2 hybrizidation? This is a very fundamental question in the field of molecular chemistry. All the molecules made by atoms. In chemistry, atoms are the fundamental particles. There are four different types of orbitals in chemistry. They are named as s, p, d, and f orbitals.

The entire periodic table arrangement are based on these orbital theory. 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

CH2Br2 molecule is made of one carbon, two hydrogens, and two bromine atoms. The bromine and carbon atoms have s and p orbital. hydrogen comes as the first element in the periodic table. The hydrogen atom has s orbital.

When these atoms combine to form the CH2Br2 molecule, its orbitals mixed and form unique molecular orbitals due to hybridization.

How do you find the CH2Br2 molecule’s hybridization? We must now determine the molecular hybridization number of CH2Br2.

The formula of CH2Br2 molecular hybridization is as follows:
No. Hyb of CH2Br2= N.A(C-H and C-Br bonds) + L.P(C)
No. Hy of CH2Br2= the number of hybridizations of CH2Br2
Number of C-H and C-Br bonds = N.A (C-Br and C-H bonds)
Lone pair on the central carbon atom = L.P(C)
Calculation for hybridization number for CH2Br2 molecule

In the CH2Br2 molecule, carbon is a core atom with two bromine and two hydrogen atoms connected to it and no lone pair. The number of CH2Br2 hybridizations (No. Hyb of CH2Br2) can then be estimated using the formula below.

No. Hyb of CH2Br2= 4+0 =4

The CH2Br2 molecule hybridization is four. The sp3 hybridization is formed when one S orbital and three p orbital join together to form a molecular orbital.

Molecular Geometry Notation for CH2Br2 Molecule :

Determine the form of CH2Br2 molecular geometry using VSEPR theory. The AXN technique is commonly used when the VSEPR theory is used to calculate the shape of the CH2Br2 molecule.

The AXN notation of CH2Br2 molecule is as follows:
The center carbon atom in the CH2Br2 molecule is denoted by the letter A.
The bound pairs (C-H and C-Br) of electrons to the core carbon atom are represented by X.
The lone pairs of electrons on the center carbon atom are denoted by the letter N.
Notation for CH2Br2 molecular geometry

We know that carbon is the core atom, with four electron pairs bound (two C-H and two C-Br) and no lone pair. The general molecular geometry formula for CH2Br2 is AX4.

According to the VSEPR theory, if the CH2Br2 molecule has an AX4 generic formula, the molecular geometry and electron geometry will both be tetrahedral forms.

Name of Molecule	Dibromomethane
Chemical molecular formula	CH2Br2
Molecular geometry of CH2Br2	Tetrahedral
Electron geometry of CH2Br2	Tetrahedral
Hybridization of CH2Br2	sp3
Bond angle (H-C-H and Br-C-Br)	112.5 and113.4º degree
Total Valence electron for CH2Br2	20
The formal charge of CH2Br2 on carbon	0

Summary:

In this post, we discussed the method to construct CH2Br2 molecular geometry, the method to find the lone pairs of electrons in the central carbon atom, CH2Br2 hybridization, and CH2Br2 molecular notation. Need to remember that, if you follow the above-said method, you can construct the CH2Br2 molecular structure very easily.