Ethylene is a hydrocarbon chemical compound having the chemical formula C2H4. It is a colorless gas with a musky or faint smell. It is flammable in nature. Many of you may have a doubt regarding whether ethylene is polar or not. In this article, I will answer this and will make you understand the parameters to determine the polarity of a molecule.
So, Is C2H4 Polar or Nonpolar? Ethylene (C2H4) is nonpolar in nature because of the symmetrical (linear) geometrical shape. Another reason is that the hydrogen-carbon bonds are nonpolar because of nearly the same electronegativity. As a result, the dipole of the molecule of Ethylene turns out to be zero.
Ethylene is a flammable gas. It is colorless in its appearance and has a musky odor. The IUPAC name of ethylene is Ethene.
It was first discovered in the year 1901 by a Russian scientist named Dimitry Neljubow.
It is the simplest hydrocarbon of the alkene family. It is used in many chemical industries. Its major product goes towards the manufacturing of polyethylene which is also known as plastic.
Polyethylene plastic is a polymer that contains a series of ethylene molecules.
If we talk about the chemical composition of the ethylene molecule, it consists of 2 carbon atoms and 4 hydrogen atoms.
Both carbon atoms are connected covalently by a double bond. And hydrogen atoms are connected by a single covalent bond with carbon atoms.
The molecular mass of the C2H4 molecule is 28.054 g·mol−1. It can be calculated as below
Mol mass of C2H4 = 2 * 12 (Mol mass of C) + 4 * 1 (Mol mass of H) = 28.054 g·mol−1.
The molecule is linear in shape with reference to carbon atoms. Often linear molecules are nonpolar in nature.
Electronegativity of an atom is the strength with which it attracts the bonded electron pair towards it. It is an important factor to determine the polarity of a molecule.
The electronegativity of carbon is 2.55 and that of hydrogen is 2.2. C-H bond is nonpolar because of the nearly same electronegativity of both atoms.
What are Polar and Nonpolar Molecules?
The molecules are bounded by the interatomic forces including metallic bonds, hydrogen bonding, ionic, and covalent bonds.
Ionic and covalent bonds are the strongest among all the above bond forces.
The covalent bond is the bond that involves the sharing of electrons of atoms for their stabilization. These electrons are also known as bonded electron pairs.
The bond can be single (single electron pair), double (two-electron pairs), and triple (three electron pairs) as well.
Polar Molecules: the molecules that have a non-uniform distribution of charge across it is known as a polar molecule.
These molecules have non zero dipole moment. The dipole is the product of charge and the distance between the centers of positive and negative charge.
Two atoms forming a polar covalent bond is said to be polar if both atoms differ in their electronegativity.
Few examples of polar substances are NF3, NCl3, H2O. You can check out the reason for the polarity of NF3.
Nonpolar Molecules: The molecules that have a uniform distribution of charge across them are known as nonpolar molecules.
These Molecules have zero dipole moment. And, it is generally seen that the shape of nonpolar molecules is symmetric.
The atoms that form a nonpolar covalent bond has equal electronegativity. Examples of such compounds are BeCl2, SF6. You can check out the reason for the non-polarity of BeCl2.
Why is C2H4 a Nonpolar Molecule?
C2H4 (Ethylene) consists of 2 carbon atom and 4 hydrogen atoms. The carbon-carbon bond is double covalent bond ie; sharing of two-electron pairs occurs.
The valence electrons of carbon are 4 and that of hydrogen is 1. Both carbon shares 2 electrons of each other and two electrons from the 2 hydrogen atoms connected covalently with carbon atoms.
As a result, both carbon and hydrogen get their octet complete to form a neutral molecule C2H4.
The electronegativity of carbon(2.55) and hydrogen(2.2) is also nearly the same due to which the C-H bond is also nonpolar.
The molecule is linear-shaped ie; symmetrical. As a result, the entire molecule also remains as a nonpolar molecule.
Being a nonpolar molecule, C2H4 molecules gives zero dipole moment.
Factors affecting polarity of a molecule
Electronegativity: the electronegativity of an atom is the measure of the strength of an atom to attract the shared bonded electron pairs towards its side.
The atom with higher electronegativity pulls the bonded electrons nearer towards it and gains a partial negative charge and other atom gains a partial positive charge.
If there is a difference between the electronegativity of two atoms forming a molecule, the molecule will be polar in nature.
As a result, the two poles (positive and negative) generate in the molecule.
The polarity of a molecule is directly proportional to the difference between the electronegativity of atoms.
Dipole Moment: The dipole of a molecule is the value of the measure of the polarity of a molecule.
Greater the dipole of a molecule more is its polarity. Its SI unit is Debye and is denoted by D.
Technically, it is the product of the charge on atoms and the distance between the center of positive and negative charge.
D = Q * R
Geometrical shape: The shape of the molecule is an important parameter to check the polarity of a molecule.
It is usually observed that the symmetrically shaped molecules are nonpolar in nature whereas the asymmetrically shaped molecules are polar.
Note: In case, if the nonpolar molecules also have the presence of polar bonds within them, the polarity of such bonds gets canceled by each other due to the symmetric shape of the molecule.
Below is the image of the geometrical molecular structure of ethylene
Properties of C2H4
- Ethylene exists as a colorless gas with a musky smell at room temperature.
- It is flammable in nature.
- The melting point of this substance is −169.2 °C or −272.6 °F and its boiling point is −103.7 °C or −154.7 °F.
- At a temperature of 15 °C, the density of this gas is1.178 kg/m3.
- Its solubility in water at 25 °C is 0.131 mg/mL.
Uses of C2H4
- It is majorly used in the industries for the manufacturing of plastic (polyethylene) that is a polymer of C2H4 molecules in series.
- It is also used for the halogenation in different chemical reactions.
- In the US and Europe, 90% of ethylene is used for the production of polyethylene, ethylene dichloride, ethylene oxide, and ethylbenzene.
- Ethylene is oxidized to form ethylene oxide that is further used as a raw material for the manufacturing of detergents and surfactants.
Ethylene (C2H4) is a linear-shaped molecule with a double bond between both carbon atoms (C=C). The C-H bond is also nonpolar because of nearly the same electronegativity.
As a result, the entire molecule is nonpolar.
So guys, if you have any questions regarding the non-polarity of C2H4, you can ask them in the comment section. We will reach out to you as soon as possible.