Xenon trioxide (XeO3) lewis structure, molecular geometry, hybridization, polar or nonpolar
Xenon trioxide is an unstable compound that appears as a colorless crystalline solid having the chemical formula XeO3. It is soluble in water and releases xenon and oxygen gas upon detonation.
In this tutorial, we will discuss Xenon trioxide (XeO3) lewis structure, molecular geometry, hybridization, polar or nonpolar, etc.
Xenon trioxide can release oxygen from water as it is a powerful oxidizing agent. The process can be fastened by exposure to light.
|Name of Molecule||Xenon trioxide|
|Molecular geometry of XeO3||Trigonal pyramidal|
|Electron geometry of XeO3||Tetrahedral|
|Total Valence electron for XeO3||26|
How to draw lewis structure of XeO3?
XeO3 lewis structure is made up of one xenon and three oxygen atom, the xenon is in a central position, and all oxygen is at the surrounding position. There are three double bonds(Xe=O) present in the XeO3 lewis structure.
The lewis structure of XeO3 contains 12 bonding electrons and 14 nonbonding electrons.
Follow some steps for drawing the Lewis structure for XeO3
1. Count total valence electron in XeO3
First of all, determine the valence electron that is available for drawing the lewis structure of XeO3. To find the valence electron, look at the group number of atoms in the periodic table.
The xenon atom belongs to group 18th in the periodic table and oxygen is situated in the 16th group, hence, the valence electron for xenon is 8 and for the oxygen atom, it is 6.
⇒ Total number of the valence electrons in xenon = 8
⇒ Total number of the valence electrons in oxygen = 6
∴ Total number of valence electron available for the XeO3 Lewis structure = 8 + 6(3) = 26 valence electrons [∴ XeO3 molecule has one xenon and three oxygen atoms]
2. Find the least electronegative atom and place it at center
An atom with a less electronegative value is more preferable for the central position in the lewis diagram because they are more prone to share the electrons with surrounding atoms.
In the case of the XeO3 molecule, the electronegativity for the xenon atom is 2.6 and for the oxygen atom, it is 3.44.
Therefore, place the xenon atom at the central position and all oxygen atoms at the surrounding position.
3. Connect outer atoms to central atom with a single bond
In this step, place the single bond in between the outer atoms(oxygen) and central atom(xenon).
After connecting each outer atom to the central atom, count the number of valence electrons used in the above structure. There are 3 single used in the above structure, and one single bond means 2 electrons.
Hence, in the above structure, (3 × 2) = 6 valence electrons are used from a total of 26 valence electrons available for drawing the XeO3 Lewis structure.
∴ (26 – 6) = 20 valence electrons
So, we are left with 20 valence electrons more.
4. Place remaining electrons on outer atoms and complete their octet
Let’s start putting the remaining valence electrons on outer atoms first. In the case of the XeO3 molecule, oxygen is the outer atom and it needs 8 electrons in the valence shell to complete the octet.
So, all oxygen atoms in the above structure completed their octet, because all of them have 8 electrons(6 electrons represented as dots + 2 electrons in every single bond) in their valence shell.
Now again count the number of valence electrons used in the above structure.
In the above structure, there are 18 electrons represented as dots + 3 single bonds means 6 electrons.
Hence, (18 + 6) = 24 total electrons are used in the above structure and we had a total of 26 valence electrons available for the XeO3 lewis structure.
∴ (26 – 24) = 2 valence electrons
So, we just are left with 2 valence electrons more.
5. Complete central atom octet
By looking at the 4th step structure, we see, the central atom Xenon is attached with the three single bonds means it has already 6 electrons in its valence shell. And we also know, we are left with 2 valence electrons.
So, just place these 2 remaining valence electrons over the xenon central atom.
So, we have used all the valence electrons that are available and all the atoms in the above structure have completed their octet since all of them have 8 electrons in their valence shell.
But the thing is, we surely don’t know whether the above XeO3 lewis structure is stable or not. To check this, we have to determine the formal charge for the above structure.
6. Check the stability with the help of a formal charge concept
The lesser the formal charge on atoms, the better is the stability of the lewis diagram.
To calculate the formal charge on an atom. Use the formula given below-
⇒ Formal charge = (valence electrons – nonbonding electrons – 1/2 bonding electrons)
Let’s count the formal charge on the oxygen atom first, all oxygen atoms in the XeO3 Lewis structure(5th step) have the same bonded pair and lone pair, so, just count the F.C. for the one oxygen atom.
For oxygen atom:
⇒ Valence electrons of oxygen = 6
⇒ Nonbonding electrons on oxygen = 6
⇒ Bonding electrons around oxygen(1 single bond) = 2
∴ (6 – 6 – 2/2) = -1 formal charge on each oxygen atom.
For xenon atom
⇒ Valence electrons of xenon = 8
⇒ Nonbonding electrons on xenon = 2
⇒ Bonding electrons around xenon (3 single bonds) = 6
∴ (8 – 2 – 6/2) = +3 formal charge on the xenon central atom.
The above XeO3 lewis structure is not stable because of the high formal charge. To reduce this, we have to rearrange the electrons and form multiple bonds.
All you have to do is to convert the one lone pair of each oxygen atom to a bond pair.
The central atom Xenon has expanded octet that means it can hold more than 8 electrons in its valence shell.
Xenon atom has d-orbital for extra electrons needed for bonding.
Now you can calculate the formal charge for each atom in the above structure, you will get the formal charge for every atom equal to zero.
XeO3 lewis structure
That’s all this is our most stable and appropriate lewis structure of XeO3.
What is the molecular geometry of XeO3?
The molecular geometry of XeO3 is Trigonal pyramidal since the central atom Xenon is attached to three bonding domains and it contains one lone pair also, so, according to VSEPR, it forms AX3N type molecule.
A represent the central atom
X represents the number of bonding domain attached to the central atom
N represent lone pair on the central atom
According to the VSEPR theory or chart, the AX3N type molecule will form a trigonal pyramidal molecular geometry. And for this type of molecule, the electron geometry will be tetrahedral. Look at the chart given below.
Hybridization of XeO3
Let’s find the hybridization of XeO3 through the steric number of its central atom.
“Steric number is the addition of a total number of bonded atoms around a central atom and the lone pair present on it.”
∴ Steric number of XeO3 = (Number of bonded atoms attached to xenon + Lone pair on xenon)
As per the lewis structure of XeO3, the xenon atom is bonded with three oxygen atoms and it contains 1 lone pair of electrons.
∴ Steric number of XeO3 = (3 + 1) = 4
So, for a steric number of four, we get the Sp3 hybridization on the xenon atom in the XeO3 molecule.
Xenon trioxide polarity: is XeO3 polar or nonpolar?
Is XeO3 polar or non-polar? XeO3 is a polar molecule because it contains three bonds(Xe-O) which are polar because of the difference of electronegativity between them, these bonds are arranged asymmetrically due to the presence of lone pair on the central atom. hence, cancellation of the bond dipole will not be possible.
This will generate some net dipole moment in the molecule, which, obviously makes the XeO3 polar in nature.
Why does Xenon in XeO3 lewis structure violate octet and holds more than 8 electrons?
In the XeO3 lewis structure, the central atom is xenon which is surrounded by 3 double bonds and contains one lone pair also means 14 total electrons, hence, its valence shell is holding more than 8 electrons which violates the octet.
“The octet rule refers to the tendency of atoms to prefer to have eight electrons in the valence shell”.
Now the xenon atom in the XeO3 lewis structure violates the octet because it has the ability to expand the octet basically called an expanded octet.
The xenon atom has a d-orbital to store the extra electrons needed for bonding. In the XeO3 lewis structure, the xenon atom has to hold more than 8 electrons for reducing the formal charge and attaining stability.
At last, we can say, the xenon atom is holding more than 8 electrons because of obtaining the most stable lewis structure of XeO3 by using its ability of expanded octet.
How many bonding and nonbonding pairs of electrons are present in the lewis structure of XeO3?
The bonding electrons are those which form a bond and are basically found in between two atoms. The nonbonding electrons are those which do not take part in bonding, basically called lone pairs and represented as dots in the lewis diagram.
Now in the XeO3 lewis structure, there are 14 nonbonding electrons(represented as dots) and 12 bonding electrons(3 double bonds).
So, the pairs of bonding electrons are 6, and pairs of nonbonding electrons are 7 in the XeO3 lewis structure.
Properties of Xenon trioxide
- It has a molar mass of 179.288 g/mol.
- It is unstable and explosive.
- It is soluble in water and behaves as a powerful oxidizing agent.
- It releases xenon and oxygen gas when detonates.
- The liberation of oxygen is accelerated by exposure to sunlight.
- Its crystal structure is orthorhombic.
- Xenon trioxide can be obtained by the evaporation of a solution generated from the hydrolysis of xenon tetrafluoride.
- It has a melting point of 25 °C and a boiling point of 0 ºC.
Reactions of Xenon trioxide
Since the xenon trioxide is explosive, at above 25 °C, it is very prone to explosion.
⇒ 2XeO3 → 2Xe + 3O2
Xenon trioxide on dissolving in water, it produces an acidic solution of xenic acid.
⇒ XeO3(aq) + H2O → H2XeO4 ⇌ H+ + HXeO4–
Xenon trioxide can react with inorganic fluorides such as RbF or CsF and form a stable solid compound.
⇒ XeO3 + RbF → RbXeO3F
⇒ XeO3 + CsF → CsXeO3F
- The total valence electron is available for drawing the XeO3 Lewis structure is 26.
- The steric number of Xenon central atom in the XeO3 molecule is 4, thus, it forms Sp3 hybridization.
- XeO3 is a polar molecule.
- The molecular geometry of XeO3 is trigonal pyramidal and its electron geometry is tetrahedral.
- Each oxygen atom in the XeO3 lewis structure has 4 electrons that do not involve in bonding.