Xenon difluoride is a chemical compound with chemical formula as XeF2. It is considered as a strong fluorinating agent. It is also one of the most stable compounds of Xenon. It is also a moisture-sensitive substance like other inorganic covalent compounds. Many students may have doubts regarding whether XeF2 is polar or not. In this article, we will discuss this in detail and will also cover its properties and applications.
So, Is XeF2 Polar or Nonpolar? XeF2 is nonpolar in nature because of its linear-shaped geometry having fluorine atoms symmetrically on both sides of the xenon atom. However Xe-F bond is polar because the electronegativity of Xe and F is different but the polarity of both Xe-F bonds gets canceled by each other resulting in a nonpolar XeF2 molecule.
Xenon difluoride exists as a dense white solid at room temperature. It is one of the most stable compounds of the Xenon family.
It decomposes on contact with vapors and light, but if stored properly, it is a stable substance.
It was discovered in the year around 1962.
The crystal structure of the XeF2 substance contains parallel units of XeF2 connected with each other.
The molecular mass of Xenon difluoride is calculated as below:
Mol mass of XeF2 = 1* 131 (Mol mass of Xe) + 2 * 55.8 (Mol mass of F) = 169.29 g·mol−1.
If we talk about the chemical composition of XeF2, the molecule contains 2 atoms of Fluorine and 1 atom of Xenon.
The Xenon is a central atom surrounded by Fluorine atoms on its both side connected to Xenon through covalent bonds.
XeF2 is synthesized when a mixture of xenon and fluorine is heated in a sealed nickel vessel. at 400 degrees Celcius in the ratio of 2:1.
Xe + F2 —–heated—–> XeF2
In a covalent bond between two atoms, both atoms share the electrons of each other in order to complete its octet. Similarly, in XeF2 molecule, Xe and F atoms shares atom of each other in order to form a stable molecule.
The Electronegativity of an atom is its strength of attracting the bonded pair electrons towards it. More electronegative atom attracts the bonded pair electron with more influence.
The electronegativity of the xenon atom is 2.6 and that of fluorine is around 3.98. Therefore, fluorine is higher electronegative than xenon.
As a result, the fluorine atom attracts the bonded electron pair slightly more towards itself and gains a partial negative charge on it.
And the xenon atom gains a partial positive charge on it.
The polarity in the Xe-F bond ensures non zero dipole moment originating from xenon to fluorine atom (Xe->F).
But due to the linear structure ie; symmetrical, the dipoles of both Xe-F bonds get canceled by each other resulting in a nonpolar XeF2 molecule.
What are Polar and Nonpolar Molecules?
The molecules that are held by the covalent bond forces can be polar and nonpolar depending upon various factors like electronegativity, dipole moment, and geometric structure of the molecule.
Polar Molecules: The molecules that have non zero value of their dipole moment are polar in nature.
These molecules have unequal distribution of charge on its atoms. It means atoms share an unequal proportion of charge.
The bond formed by two atoms is said to be polar if both atoms differ in their electronegativity.
Few examples of such molecules are OF2, CO. You can check out the reason for the polarity of CO.
Nonpolar Molecules: The molecules that have zero dipole moment are nonpolar in nature. These molecules have equal charge distribution on their atoms.
The atoms of nonpolar molecules share equal charge. The covalent bond formed by two atoms is said to be nonpolar if both atoms have equal electronegativity.
Few examples of such atoms are Hexane, SO3, O2, etc. You can check out the reason for the non-polarity of Cl2.
Why is XeF2 a nonpolar molecule?
Xenon difluoride consists of two fluorine atoms and one xenon atom. Xe and F atoms form covalent bonds with each other.
Being more electronegative, the fluorine atom attracts the bonded electron pair slightly more towards it and gains a partial negative charge.
On the other hand, the xenon atom gains a partial positive charge.
Due to the difference between the electronegativity of fluorine and xenon atom, the molecule of XeF2 ensures non zero dipole moment originating in the direction of fluorine.
The dipole moment of a molecule is the measure of its polarity.
Both Xe-F atoms have equal dipole moment but in the opposite direction of each other due to which the net dipole moment of the entire molecule turns out to be zero.
Therefore, the Dipole moment of XeF2 is 0 D.
Have a look at the below image of the geometrical structure of the XeF2 molecule.
Factors affecting polarity of a molecule
Electronegativity: It is termed as the strength of an atom to attract the bonded pair electrons towards its side. The higher electronegative atom attracts the bonded electrons slightly more towards its side.
If there is a difference between the electronegativity of two atoms forming a covalent bond, the polarity rises in such bonds.
The polarity of a molecule is directly proportional to the difference between the electronegativity of two atoms forming that molecule.
Geometrical shape: The shape of a molecule is an important parameter to check whether a molecule is polar or not.
The symmetrically shaped molecules are nonpolar in nature whereas the molecule that is asymmetric is polar in nature.
Dipole Moment: The molecule’s polarity is measured by its dipole moment. It is denoted by D. It SI unit is Debye.
The molecules that are nonpolar have 0 dipole moment value.
It is a vector quantity ie; have magnitude as well as direction.
D = Q * R
Properties of XeF2
- Xenon difluoride is considered as a powerful fluorinating agent.
- This substance exists as a white solid crystal in appearance.
- It decomposes in the presence of light and vapors. But if stored properly, it is one of the most stable xenon compounds.
- The density of this substance 4.32 g/cm³.
- The molecular mass of xenon difluoride is 169.29 g/mol.
- Its melting point is 128.6 °C or 263.5 °F, and its boiling point is around 155 °C.
- This substance is insoluble in water.
Uses of XeF2
- It is widely used as a fluorinating agent ie; used to fluorinate the hetero element present in the organometallic compound.
- It is used for the purpose of detection and determination of very small amounts of iodine on the basis of the oxidation of iodine to periodate.
- It is also used as an antiseptic ie; to kill bacteria.
Xenon difluoride molecule consists of one xenon atom surrounded by two fluorine atoms on both sides.
The Xenon and fluorine atoms differ in the electronegativity due to which polarity and dipole in the Xe-F bond generate.
But due to symmetric (linear-shaped) of the molecule, the dipoles get canceled by each other resulting in a nonpolar XeF2 molecule.
Therefore, due to these reasons, XeF2 is a nonpolar molecule.
Guys, if you have any questions regarding the non-polarity of XeF2, you can ask them in the comment section. We will reach out to you as soon as possible.