 # I3 Lewis Structure

Knowing the i3 Lewis structure and understanding its physical properties, hybridization, and molecule shape is critical. We are going to go through the Lewis structure of I3 today, or we also know it as a Tri-iodide ion because it has a negative charge on it. There are three iodine molecules in this molecule, which is why Tri-iodide is the name of the compound. ## What is the Lewis Structure?

The structure of Lewis is a reflection of molecular electrons. There are lone pairs and valence electrons that assist in determining the molecule’s hybridization and form. Since there are iodine molecules, there will be one iodine molecule in the center. Iodine is also in the periodic table’s seventh group and has seven valence electrons in its outer orbit.

We have three iodine molecules here, along with an extra electron that gives a negative charge. So the total number of electrons of valence is: 7 * 3 + 1 = 22.

The total number of valence electrons is 22 in this molecule. Now there is an octet law that is followed by an atom. Per atom should have eight electrons in its outer orbit, as per this law?

If in the outer shell of the central atom there are 8 electrons, there are two other atoms that need to complete their octet. As all atoms need eight electrons in their outer shell to complete the octet, both the neighboring iodine atoms will take one electron from the central iodine atom. That would say 8-1-1=6.

Since the electrons are taken from both atoms.

So now there will be six of the valence electrons on the central iodine atom. The lone pairs of electrons which do not bind will form these six electrons. There will be three lone pairs and two bond pairs of electrons as each iodine atom has a bond with the central atom sharing one electron each with a total of 3 lone pairs and 2 bond pairs on the central atom as it forms the pair of electrons now.

## Hybridization of I3

There is a basic formula that can be used for understanding the hybridization of any molecule. This formula is used to figure out the number of hybridizations that help to understand the molecule’s hybridization.

The numbers of the hybrid and the hybridization it defines are as follows:

1. Hybridization in sp

2. Hybridization sp2

3. Hybridization sp3

4. Hybridization

The number finding formula is,

Number of hybridization: Valence electron number + monovalent + (negative charge)-(positive charge)/2

The iodine atoms’ valence electrons are 7 since there are seven electrons in the outermost shell. Since two out of three iodines are monovalent, the monovalent atom number is two.

It has a negative charge now when we get to the charge of the I3-ion, so the amount of this negative charge would be 1.

Now, according to the formula, position all the values

7 + 1 + 2 /2 2/2

=10/2/2 =

=5

Therefore, the hybridization number is 5, which means that sp3d is hybridization.

Using lone pairs and valence electrons, another way to find the hybridization of a given molecule is. In this molecule, the number of lone pairs is 3, and the number of valence electrons sharing atoms is 2.

Thus, 3+2=5, which also specifies the hybridizations of sp3d? ## The shape of I3-

The molecule shape I3- is linear in form. There are three atoms of iodine, of which one has an additional negative charge. There are 3 lone pairs of electrons and 2 bond pairs due to this one extra electron, which makes it steric number 5. These pairs attempt to repel each other as much as possible since there are three lone pairs on the central Iodide atom.

So the pairs take equatorial positions to be away at a greater distance, and the other two iodine atoms are 180 degrees from each other. The overall form of the I3-ion is thus linear.

## Polarity of i3

So here’s the tricky thing about this ion, we should call it a polyatomic ion instead of calling it a molecule, first of all, like it as a charge on it. The charges on the molecules that we see are ions. Since I3- has one electron, this ion has an overall negative charge. Molecules have polarity because they all have charges that are partly charged positively and partly charged negatively.

Depending upon the separation of the charges on the atom, there is a dipole moment on the molecules. The dipole moment would also be larger if the distance between both charges is greater.

But the I3-ion is a negatively charged ion when we talk about it. We do not see any dipole moment of the polar bonds in it as the total charge itself is negative on the ion, even when we draw its Lewis structure. So it’s not polar or nonpolar either. Nevertheless, if you have to define the ion, you can use the term like a polar molecule because I3- is water-soluble.

## Properties of Tri-Iodide Ion

Let us discuss those characteristics of the triiodide molecule.

1. The triiodide ion, from which most polyiodides exist, is the simplest polyiodide. It appears yellow in the low concentration and brown in the solutions in the higher concentration. The blue-black color is responsible for the triiodide ion, a well-known one that happens when iodine solution interacts with starch, or when iodine solutions in the non-polar solution do not occur.
2. Lugol’s iodine contains a stoichiometric quantity of elemental iodine and potassium iodide, so this solution contains a large amount of triiodide ion.
3. Iodine tincture, which is a nominal solution of elemental iodine in ethanol, also contains a large amount of tri iodide due to its iodide and water content.

## Molecular Geometry of I3

Linear is the molecular geometry of I3. While there are three atoms of iodine, one of the atoms has a negative charge that also provides two pairs of bonds and three lone pairs of electrons. The stereo number will be five. The 3 lone pairs are repelled and the equatorial positions are taken up. The remaining two atoms of iodine are 180 degrees apart from each other.

## The VSEPR Model

As well as the structures of many molecules and polyatomic ions with a central metal atom, the VSEPR model can predict the structure of nearly any molecule or polyatomic ion in which the central atom is a nonmetal. The model of the VSEPR is not a theory; it does not try to explain observations.

Instead, it is a counting process that effectively improves a large number of compounds’ three-dimensional structures, which could not be predicted using the Lewis electron-pair approach.

## VSEPR Model of Tri-iodide Ion

1. Seven electrons and one negative charge are added by each iodine atom, so the Lewis electron structure is linear.
2. In I3, there are five electron groups, two bonding pairs, and three lone pairs, around the central atom. The groups are drawn to the corners of a trigonal bipyramid to mitigate repulsion.
3. I3’ has a total of five electron pairs with two bonding pairs and three lone pairs. We must now determine how in a trigonal bipyramid to organize the lone pairs of electrons in a way that minimizes repulsions. It removes 90° LP-LP repulsions by positioning them in the axial positions and minimizes the number of 90° LP-BP repulsions.
4. There are equivalent interactions of the three lone pairs of electrons with the three iodine atoms, so we do not foresee any variations in bonding angles.
5. The molecular geometry of I3− is linear with three nuclei and three lone pairs of electrons. This can be described as a trigonal bipyramid with three missing equatorial vertices. As predicted, the ion has an I-I-I angle of 180°.

## Lone Pairs of I3

There are three lone pairs of electrons in an iodine atom. The central atom in I3(-) has 3 lone electron pairs and produces two bonds with adjacent iodine. It, therefore, carries a negative charge on it. Thus, the total number of lone electron pairs in the I3 structure is 9.

I3 is generally referred to as ion triiodide. It is a polyhalogen ion and is made up of three atoms of iodine. It is formed by mixing iodide salts and iodine in an aqueous solution. It is a linear atom and it is formed by I2 and I(-) ion binding. In solution, triiodide is red. I(-) is a donor atom in this molecule and I2 is an acceptor atom.

In the empty d orbital of iodine, the electrons are accommodated. The central atom gains a negative charge whose value is 1. during the combination of iodine atoms. Tri iodide ion hybridization is SP3D. With a bond angle of 180 degrees, the geometry of tri-iodide ions is linear. ## Frequently Asked Question (FAQs)

Below you get some most common questions about the Lewis structure of I3 which can also helps the students of chemistry.

### Does i3 have an octet in its entirety?

Lewis Dot of Triiodide Ion I3- The octet rule is not followed by me. More than 8 electrons will hold it. At the 4th energy level, iodine with valence electrons will also have access to the 4d sublevel, thus allowing for more than 8 electrons.

### Why is i3 linear?

I3- linear is molecular geometry. While there are three iodine atoms, one of the atoms has a negative charge, providing 3 lone electron pairs and 2 bond pairs. The three lone pairs will repel one another and take equatorial positions.

### Is i3 nonlinear or linear?

For 5 regions of electron density, I3- has 2 bonds and 3 lone pairs. The lone pairs go equatorial and the other two I atoms go axial, placing this into a trigonal bipyramidal structure. The molecule is linear, with three atoms in a line.

## Conclusion

In closing remarks, I3- is a polyatomic ion that has 22 valence electrons, 3 lone pairs, 2 bond pairs, and sp3d hybridization, to sum up, this entire article. In shape, it is linear and has no polarity.

## Read Also

The shape of the I3- the molecule is the Linear. There exist 3 Iodine atoms out of the 1 have an extra negative charge. Due to the, one extra electron, there are the 3 lone pairs of the electrons or 2 bond pairs, making its steric number as 5.

Lewis Dot of the Triiodide Ion I3- I does not follow the octet rule. This would hold more than 8 electrons. Iodine having valence electrons in the 4th energy level would also have access to the 4d sublevel, thus allowing for the more than 8 electrons. This is the important to the know the Lewis structure of the molecule to the understand its physical properties, hybridization, or shape of the molecule.

Today we are the going to the go through the Lewis structure of the I3- or also know as Triodide ion as this has the negative charge on the it. There three molecules of the iodine in the this molecule or hence the name of the compound are the Triodide. for the understanding the Lewis structure of the molecule, we should know valence electrons of the iodine molecule.

Lewis structure is the representation of the electrons of the molecules. There are the lone pairs or valence electrons which help in the determining the hybridization or shape of the molecule. As there are the molecules of the Iodine, one molecule of the Iodine would be in the centre. Also, iodine is the in the seventh group of the periodic table or has seven valence electrons in the its outer orbit. We have three molecules of the iodine here which along with the an extra electron which gives this the negative charge. So the total number of the valence electrons are the : 7×3 + 1= 22.

There are the 22 valence electrons in the total in the this molecule. Now there is the an octet rule this every atom follows. As per this rule, every atom should have eight electrons in the their outer orbit. If there are the 8 electrons in the the outer shell of the the central atom, there are the two other atoms this need to the complete their octet. As all the atoms would require eight electrons in the their outer shell to the complete the octet one electron of the the central Iodine atom would be taken by both the neighbouring Iodine atoms. this means 8-1-1=6. As the electrons would be taken by both the atoms.

So now the valence electrons on the the central atom of the iodine would be six. These six electrons would form the lone pairs of the electrons this do not bond. As this forms the pair of the electrons now, there would be three lone pairs, or two bond pairs of the electrons as each Iodine atoms has the bond with the central atom sharing one electron each in the total there 3 lone pairs or 2 bond pairs on the central atom.

## What is the structure of I3 minus?

For knowing the hybridization of the any molecule, there is the simple formula which may be used. This formula is the used for the finding out the hybridisation number which helps in the knowing the hybridisation of the molecule. The hybrid numbers or the hybridisation this determines are the stated as follows:

• 2: sp hybridisation

• 3: sp2 hybridisation

• 4: sp3 hybridisation

• 5: hybridisation

The formula for the finding the number is, Hybridization Number: Number of the valence electron + monovalent + (negative charge) – (positive charge)/2

The valence electrons of the iodine atoms are the 7 as there is the seven electron in the outermost shell. The number of the monovalent atom is the two as the two out of the three iodines are the monovalent. Now if we come to the charge of the I3- ion this has the negative charge so the value of the this negative charge would be 1. Now place all the values according to the formula,

7+1+2/2

=10/2

=5

Thus the hybridisation number is the 5 which means it’s hybridisation is the sp3d. Another way of the finding the hybridisation of the given molecule is the with the help of the lone pairs or valence electrons. The number of the lone pairs in the this molecule is the 3, or the number of the atoms sharing valence electrons is the 2.

Hence, 3+2=5 which also determines sp3d hybridisation.

### What is the structure of I3 plus?

The shape of the I3- Ion. The shape of the molecule I3- is the Linear. There are the three Iodine atoms out of the which one has an extra negative charge. Due to the this one extra electron there 3 lone pairs of the electrons or 2 bond pairs making it’s steric number 5. As there are the three lone pairs on the central Iodide atom, these pairs try to the repel each other as much as possible. So in the order to the be away at the greater distance, the pairs take the equatorial positions, or the other two Iodine atoms are the 180 degrees from the one another. Thus the overall shape of the I3- ion is the linear.

So here is the tricky part about this ion, first of the all like this as the charge on the this we may call this as the polyatomic ion instead of the calling this the molecule. Ions are the charges we see on the molecules. As I3- has one electron, this Ion has the negative charge overall. Molecules have polarity because this has both the charges this are the partially positively charged end or the partially negatively charged end. There is the dipole moment on the molecules depending upon the separation of the charges on the molecule. If the distance between both the charges is the larger the dipole moment would also be larger.

But if we talk about I3- ion this is the the negatively charged ion. Even if we draw, it’s Lewis structure we do not see any dipole moment or the polar bonds in the this as the overall charge itself is the negative on the the ion. So this is the neither polar or nonpolar. However, if you have to the describe the ion, you may use the phrase the “ like the polar molecule” because I3- is the soluble in the water.

In concluding remarks, to the sum up, this entire article, I3- is the polyatomic ion this has 22 valence electrons, 3 lone pairs, 2 bond pairs, or sp3d hybridization. This is the linear in the shape or has no polarity.

Here we would learn how to the determine the hybridization of the I3-. One key thing this students have to the remember is the this I3− is the linear anion. this is the formed by the bonding of the I2 with the I− ion. Here I− ion would be the donor or I2 molecule would be the acceptor where electrons are the usually accommodated in the empty d orbitals. I3- ion is the basically sp3d hybridized.

Name of the the Molecule Triiodide ion

Molecular Formula I3-

Hybridization Type sp3d

Bond Angle 180o

Geometry Linear

What is the the Hybridization of the Triiodide ion?

To know the hybridization of the Triiodide ion, we may use simple hybridization formula which is the given as; Number of the Hybridization = Valence electron + monovalent + (negative charge) – (positive charge)/2

If we look at the the iodine atoms there are the seven valence electrons in the its outer shell or two monovalent atoms are the also present. Further, during the combination of the Iodine with the the two other Iodine atoms, the central atom gains the negative charge whose value would be taken as 1. If we place or substitute the values according to the the formula, we get

7+1+2/2

=10/2

=5

Therefore the hybridisation number is the equal to the 5. Now we may say this hybridisation is the sp3d. Alternatively, we may also determine the hybridization of the I3- by knowing the number of the valence electrons or lone pairs or calculating their sum. in the this case, if we consider the lone pairs there are the 3 such pairs while the number of the atoms donating valence electrons is the 2. If we add these values together we take 5 which may be interpreted as sp3d hybridisation.

I3- is the formed by the bonding of the I2 with the I− ion. During the combination of the Iodine atoms, the central atom gains the negative charge whose value would be 1. I− ion is the donor or I2 molecule is the acceptor. Electrons are the mostly accommodated in the empty d orbitals.

I3- Molecular Geometry or Bond Angles. I3- molecular geometry is the linear. While there are the three Iodine atoms, one of the atoms has the negative charge which further gives 3 lone pairs of the electrons or 2 bond pairs. Its steric number would be 5. The three lone pairs would repel each other or take up equatorial positions. The remaining two Iodine atoms are the at the 180o from the each other.

FAQs

Yes

Yes

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