I2 Molecular Geometry - Science Education and Tutorials

Iodine solid (tend move to gas state)(I2) has the composition of one iodine and one iodine atom. What is the molecular geometry of iodine soft solid?. Drawing and predicting the I2 molecular geometry is very easy by following the given method. Here in this post, we described step by step how to construct I2 molecular geometry. Iodine and iodine come from the 17th family groups in the periodic table. Both iodines have seven valence electrons in each.

Table of Contents

Key Points To Consider When drawing The I2 Molecular Geometry

A three-step approach for drawing the I2 molecular can be used. The first step is to sketch the molecular geometry of the I2 molecule, to calculate the lone pairs of the electron in the terminal iodine atom; the second step is to calculate the I2 hybridization, and the third step is to give perfect notation for the I2 molecular geometry.

The I2 molecular geometry is a diagram that illustrates the number of valence electrons and bond electron pairs in the I2 molecule in a specific geometric manner. The geometry of the I2 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 I2 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 I-I single bonds (dipole moment properties of the I2 molecular geometry). One iodine-iodine single bonds in the iodine solid (I2), for example, are polarized toward the more electronegative value iodine atom, and because (I-I) single bonds have the same size and polarity, their sum is nonzero due to the I2 molecule’s bond dipole moment due to pulling the electron cloud to the two side of linear or tetrahedral geometry, and the I2 molecule is classified as a nonpolar molecule.

The molecule of iodine solid(with tetrahedral shape I2 molecular geometry) is tilted at 180 degrees bond angle of I-I. It has a difference in electronegativity values between iodine and iodine atoms, with iodine’s pull the electron cloud being greater than iodine. But the bond polarity of I-I is not canceled to each other in the linear or tetrahedral geometry. As a result, it has a nonzero permanent dipole moment in its molecular structure. The I2 molecule has a nonzero dipole moment due to an unequal charge distribution of negative and positive charges in the linear or tetrahedral geometry.

Overview: I2 electron and molecular geometry

According to the VSEPR theory, the I2 molecule ion possesses linear or tetrahedral molecular geometry. Because the center atom, iodine, has one I-I single bond with the one iodine atom surrounding it. The I-I bond angle is 180 degrees in the tetrahedral I2 molecular geometry. The I2 molecule has a linear or tetrahedral geometry shape because it contains one iodine atom in the tetrahedral and three corners with three lone pairs of electrons.

There is one I-I single bond at the I2 molecular geometry. After linking the one iodine atom and three lone pairs of electrons on the iodine atom in the tetrahedral form, it maintains the tetrahedral-shaped structure. In the I2 molecular geometry, the I-I single bond has stayed in the one terminal and three lone pairs of electrons on the iodine atom of the tetrahedral molecule.

The center iodine atom of I2 has three lone pairs of electrons, resulting in tetrahedral I2 electron geometry. However, the molecular geometry of I2 looks tetrahedral or linear-shaped and has three lone pairs of electrons on the iodine of the I2 geometry. It’s the I2 molecule’s slight symmetrical geometry. As a result, the I2 molecule is slightly nonpolar.

How to find I2 hybridization and molecular geometry

Calculating lone pairs of electrons on iodine in the I2 geometry:

1.Determine the number of lone pairs of electrons in the core iodine atom of the I2 Lewis structure. Because the lone pairs of electrons on the iodine atom are mostly responsible for the I2 molecule geometry planar, we need to calculate out how many there are on the terminal iodine atom of the I2 Lewis structure.

Use the formula below to find the lone pair on the iodine atom of the I2 molecule.

L.P(I) = V.E(I) – N.A(I-I)

Lone pair on the terminal iodine atom in I2 = L.P(I)

The core terminal iodine atom’s valence electron in I2 = V.E(I)

Number of I-I bond = N.A (I-I)

calculation for iodine atom lone pair in I2 molecule.

For instance of I2, the terminal atom, iodine, has seven electrons in its outermost valence shell, one I-I single bond connection. This gives a total of one connection.

As a result of this, L.P(I) = (7 –1)=6

The lone pair of electrons in the iodine atom of the I2 molecule is three.

Calculating lone pair of electrons on iodine in the I2 geometry:

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

Use the formula below to find the lone pair on the iodine atom of the I2 molecule.

L.P(I) = V.E(I) – N.A(I-I)

Lone pair on the terminal iodine atom in I2 = L.P(I)

Terminal iodine atom’s valence electron in I2= V.E(I)

Number of I-I bonds = N.A ( I-I)

calculation for iodine atom lone pair in I2 molecule.

For instance of I2, their terminal atoms, iodine, have seven electrons in its outermost valence shell, one I-I single bond connection. This gives a total of one I-I single bond connection. But we are considering only one connection for the calculation.

As a result of this, L.P(I) = (7 –1)=6

The lone pair of electrons in the iodine atom of the I2 molecule is six. One iodine atom is connected with the terminal iodine atom.

In the I2 electron geometry structure, the lone pairs on the terminal iodine atom are three, lone pairs of electrons in the iodine atom have zero. One iodine atom has no lone pairs of electrons.

It means there are three lone pairs of electrons in the core iodine atom. Three lone pair of electrons on the terminal iodine atom are responsible for the linear or tetrahedral nature of I2 molecular geometry. But in the structure iodine atoms are polarized sidewise in their linear or tetrahedral geometry.

The three lone pairs of electrons are placed at another side of the I2 geometry. Because the iodine atom is a lower electronegativity value as compared with other atoms in the I2 molecule. One iodine atom is polarized towards the sidewise in the I2 structure.

But in reality, the I2 has three lone pairs of electrons in its structure. This makes the I2 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 iodine empty hole and lone pairs of electrons of iodine of another I2 molecule. Here, iodine of one molecule acts as an acceptor and iodine of another molecule as a donor. This is called iodine bonding between the two I2 molecules. This is one of the main intermolecular forces in I2.

But in the terminal, a iodine atom has three lone pairs of electrons and these lone pair electrons are placed in the three corners of the tetrahedral.

Calculate the number of molecular hybridizations of the I2 molecule

What is I2 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

The I2 molecule is made of one iodine and iodine atom. The iodine and iodine atoms have s and p orbitals. But the iodine atom has only s orbital in the ground state. iodine comes as the first element in the periodic table. The iodine 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 I2 molecule, its atomic orbitals are mixed and form unique molecular orbitals due to hybridization.

How do you find the I2 molecule’s hybridization? We must now determine the molecular hybridization number of I2.

The formula of I2 molecular hybridization is as follows:

No. Hyb of I2= N.A(I-I bond) + L.P(I)

No. Hy of I2 = the number of hybridizations of I2

Number of I-I bonds = N.A (I-I bonds)

Lone pair on the terminal iodine atom = L.P(I)

Calculation for hybridization number for I2 molecule

In the I2 molecule, iodine is a core terminal atom with one iodine atom connected to it. It has three lone pairs of electrons on iodine. The number of I2 hybridizations (No. Hyb of I2) can then be estimated using the formula below.

No. Hyb of I2= 3+1=4

The I2 molecule ion hybridization is four. The iodine and iodine atoms have s and p orbitals. The sp3 hybridization of the I2 molecule is formed when one s orbital and three p orbitals join together to form the I2 molecular orbital.

Molecular Geometry Notation for I2 Molecule :

Determine the form of I2 molecular geometry using VSEPR theory. The AXN technique is commonly used when the VSEPR theory is used to calculate the shape of the I2 molecule.

The AXN notation of I2 molecule is as follows:

The terminal iodine atom in the I2 molecule is denoted by the letter A.

The bound pairs (one I-I bonds) of electrons to the core iodine atom are represented by X.

The lone pairs of electrons on the terminal iodine atom are denoted by the letter N.

Notation for I2 molecular geometry

We know that I2 is the core atom, with seven electrons pair bound (one I-I) and three lone pairs of electrons. The general molecular geometry formula for I2 is AX1N3.

According to the VSEPR theory, if the I2 molecule ion has an AX1N3 generic formula, the molecular geometry and electron geometry will both be tetrahedral or linear-shaped forms.

Name of Molecule	iodine (blackish-brown solid)
Chemical molecular formula	I2
Molecular geometry of I2	Tetrahedral or linear
Electron geometry of I2	Tetrahedral or linear
Hybridization of I2	sp3
Bond angle (I-I)	180º degree
Total Valence electron for I2	14
The formal charge of I2 on iodine	0

Summary:

In this post, we discussed the method to construct I2 molecular geometry, the method to find the lone pairs of electrons in the terminal I2 atom, I2 hybridization, and I2 molecular notation. Need to remember that, if you follow the above-said method, you can construct the I2 molecular structure very easily.