Hydrogen iodide or hydroiodic acid(HI) has the composition of one iodine and one hydrogen atom. What is the molecular geometry of hydrogen iodide?. Drawing and predicting the HI molecular geometry is very easy by following the given method. Here in this post, we described step by step to construct HI molecular geometry. Iodine and hydrogen come from the 17th and 1st family groups in the periodic table. Iodine and hydrogen have seven and one valence electrons respectively.
Key Points To Consider When drawing The HI Molecular Geometry
A three-step approach for drawing the HI molecular can be used. The first step is to sketch the molecular geometry of the HI molecule, to calculate the lone pairs of the electron in the central iodine atom; the second step is to calculate the HI hybridization, and the third step is to give perfect notation for the HI molecular geometry.
The HI molecular geometry is a diagram that illustrates the number of valence electrons and bond electron pairs in the HI molecule in a specific geometric manner. The geometry of the HI 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 HI 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 H-I single bonds (dipole moment properties of the HI molecular geometry). One hydrogen-iodine single bonds in the hydrogen iodide(HI), for example, are polarised toward the more electronegative value iodine atom, and because (H-I) single bonds have the same size and polarity, their sum is nonzero due to the HI molecule’s bond dipole moment due to pulling the electron cloud to the two side of linear or tetrahedral geometry, and the HI molecule is classified as a polar molecule.
The molecule of hydrogen iodide(with tetrahedral shape HI molecular geometry) is tilted at 180 degrees bond angle of H-I. It has a difference in electronegativity values between iodine and hydrogen atoms, with iodine’s pull the electron cloud being greater than hydrogen’s. But bond polarity of H-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 HI molecule has a nonzero dipole moment due to an unequal charge distribution of negative and positive charges in the linear or tetrahedral geometry.
Overview: HI electron and molecular geometry
According to the VSEPR theory, the HI molecule ion possesses linear or tetrahedral molecular geometry. Because the center atom, iodine, has one H-I single bond with the one hydrogen atom surrounding it. The H-I bond angle is 180 degrees in the tetrahedral HI molecular geometry. The HI molecule has a linear or tetrahedral geometry shape because it contains one hydrogen atom in the tetrahedral and three corners with three lone pairs of electrons.
There is one H-I single bond at the HI molecular geometry. After linking the one hydrogen atom and three lone pairs of electrons on the iodine atom in the tetrahedral form, it maintains the tetrahedral-shaped structure. In the HI molecular geometry, the H-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 HI has three lone pairs of electrons, resulting in tetrahedral HI electron geometry. However, the molecular geometry of HI looks tetrahedral or linear-shaped and has three lone pairs of electrons on the iodine of the HI geometry. It’s the HI molecule’s slight asymmetrical geometry. As a result, the HI molecule is polar.
How to find HI hybridization and molecular geometry
Calculating lone pairs of electrons on iodine in the HI geometry:
1.Determine the number of lone pairs of electrons in the core iodine atom of the HI Lewis structure. Because the lone pairs of electrons on the iodine atom are mostly responsible for the HI molecule geometry planar, we need to calculate out how many there are on the central iodine atom of the HI Lewis structure.
Use the formula below to find the lone pair on the iodine atom of the HI molecule.
L.P(I) = V.E(I) – N.A(H-I)
Lone pair on the central iodine atom in HI= L.P(I)
The core central iodine atom’s valence electron in HI = V.E(I)
Number of H-I bond = N.A (H-I)calculation for iodine atom lone pair in HI molecule.
For instance of HI, the central atom, iodine, has seven electrons in its outermost valence shell, one H-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 HI molecule is three.
Calculating lone pair of electrons on hydrogen in the HI geometry:
Finding lone pair of electrons for the terminal hydrogen atom is similar to the central iodine atom. We use the following formula as given below
Use the formula below to find the lone pair on the hydrogen atom of the HI molecule.
L.P(H) = V.E(H) – N.A(H-I)
Lone pair on the terminal hydrogen atom in HI = L.P(H)
Terminal hydrogen atom’s valence electron in HI= V.E(H)
Number of H-I bonds = N.A ( H-I)calculation for hydrogen atom lone pair in HI molecule.
For instance of HI, their terminal atoms, hydrogen, have one electron in its outermost valence shell, one H-I single bond connection. This gives a total of one H-I single bond connection. But we are considering only one connection for the calculation.
As a result of this, L.P(H) = (1 –1)=0
The lone pair of electrons in the hydrogen atom of the HI molecule is zero. One hydrogen atom is connected with the central iodine atom.
In the HI electron geometry structure, the lone pairs on the central iodine atom are three, lone pairs of electrons in the hydrogen atom have zero. One hydrogen 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 central iodine atom is responsible for the linear or tetrahedral nature of HI molecular geometry. But in the structure hydrogen atom is polarised sidewise in their linear or tetrahedral geometry.
The three lone pairs of electrons are placed at another side of the HI geometry. Because the hydrogen atom is a lower electronegative value as compared with other atoms in the HI molecule. One hydrogen atom is polarized towards the sidewise in the HI structure.
But in reality, the HI has three lone pairs of electrons in its structure. This makes the HI 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 hydrogen empty hole and lone pairs of electrons of iodine of another HI molecule. Here, hydrogen of one molecule acts as an acceptor and iodine of another molecule as a donor. This is called hydrogen bonding between the two HI molecules. This is one of the main intermolecular forces in HI.
But in the central, 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 HI molecule
What is HI 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
f-block elementsAtoms are classified in the periodic table
HI molecule is made of one iodine and the hydrogen atom. The hydrogen and iodine atoms have s and p orbitals. But hydrogen atom has only s orbital in the ground state. Hydrogen 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 HI molecule, its atomic orbitals are mixed and form unique molecular orbitals due to hybridization.
How do you find the HI molecule’s hybridization? We must now determine the molecular hybridization number of HI.
The formula of HI molecular hybridization is as follows:
No. Hyb of HI= N.A(H-I bond) + L.P(I)
No. Hy of HI= the number of hybridizations of HI
Number of H-I bonds = N.A (H-I bonds)
Lone pair on the central iodine atom = L.P(I)Calculation for hybridization number for HI molecule
In the HI molecule, iodine is a core central atom with one hydrogen atom connected to it. It has three lone pairs of electrons on iodine. The number of HI hybridizations (No. Hyb of HI) can then be estimated using the formula below.
No. Hyb of HI= 3+1=4
The HI molecule ion hybridization is four. The iodine and hydrogen atoms have s and p orbitals. The sp3 hybridization of the HI molecule is formed when one s orbital and three p orbitals join together to form the HF molecular orbital.
Molecular Geometry Notation for HI Molecule :
Determine the form of HI molecular geometry using VSEPR theory. The AXN technique is commonly used when the VSEPR theory is used to calculate the shape of the HI molecule.
The AXN notation of HI molecule is as follows:
The central iodine atom in the HI molecule is denoted by the letter A.
The bound pairs (one H-I bond) of electrons to the core iodine atom are represented by X.
The lone pairs of electrons on the central iodine atom are denoted by the letter N.Notation for HI molecular geometry
We know that HI is the core atom, with one electron pair bound (one H-I) and three lone pairs of electrons. The general molecular geometry formula for HI is AX1N3.
According to the VSEPR theory, if the HI molecule ion has an AX1N3 generic formula, the molecular geometry and electron geometry will both be tetrahedral or linear-shaped forms.
|Name of Molecule||Hydrogen iodide|
|Chemical molecular formula||HI|
|Molecular geometry of HI||Tetrahedral or linear|
|Electron geometry of HI||Tetrahedral or linear|
|Hybridization of HI||sp3|
|Bond angle (H-I)||180º degree|
|Total Valence electron for HI||8|
|The formal charge of HI on iodine||0|
In this post, we discussed the method to construct HI molecular geometry, the method to find the lone pairs of electrons in the central HI atom, HI hybridization, and HI molecular notation. Need to remember that, if you follow the above-said method, you can construct the HF molecular structure very easily.
What is HI Molecular geometry?
HI Molecular geometry is an electronic structural representation of molecules.
What is the molecular notation for HI molecule?
HI molecular notation is AX1N3.
The polarity of the molecules
The polarity of the molecules are listed as follows
- Polarity of BeCl2
- Polarity of SF4
- Polarity of CH2Cl2
- Polarity of NH3
- Polarity of XeF4
- Polarity of BF3
- Polarity of NH4+
- Polarity of CHCl3
- Polarity of BrF3
- Polarity of BrF5
- Polarity of SO3
- Polarity of SCl2
- Polarity of PCl3
- Polarity of H2S
- Polarity of NO2+
- Polarity of HBr
- Polarity of CS2
- Polarity of HCl
- Polarity of CH3F
- Polarity of SO2
- Polarity of CH4
Lewis Structure and Molecular Geometry
Lewis structure and molecular geometry of molecules are listed below
- CH4 Lewis structure and CH4 Molecular geometry
- BeCl2 Lewis Structure and BeCl2 Molecular geometry
- SF4 Lewis Structure and SF4 Molecular geometry
- CH2Cl2 Lewis Structure and CH2Cl2 Molecular geometry
- NH3 Lewis Structure and NH3 Molecular geometry
- XeF4 Lewis Structure and XeF4 Molecular geometry
- BF3 Lewis Structure and BF3 Molecular geometry
- NH4+ Lewis Structure and NH4+ Molecular geometry
- CHCl3 Lewis Structure and CHCl3 Molecular geometry
- BrF3 Lewis Structure and BrF3 Molecular geometry
- BrF5 Lewis Structure and BrF5 Molecular geometry
- SO3 Lewis Structure and SO3 Molecular geometry
- SCl2 Lewis structure and SCl2 Molecular Geometry
- PCl3 Lewis structure and PCl3 Molecular Geometry
- H2S Lewis structure and H2S Molecular Geometry
- NO2+ Lewis structure and NO2+ Molecular Geometry
- HBr Lewis structure and HBr Molecular Geometry
- CS2 Lewis structure and CS2 Molecular Geometry
- CH3F Lewis structure and CH3F Molecular Geometry
- SO2 Lewis structure and SO2 Molecular Geometry
- HCl Lewis structure and HCl Molecular Geometry
- HF Lewis structure and HF Molecular Geometry