Is C2H4 a polar or nonpolar substance?

C2H4 is the molecular formula for ethylene, a hydrocarbon chemical molecule. It’s a colourless gas that has a musky or subtle odour to it. It is naturally flammable. Many of you may have doubts about whether or not ethylene is polar. In this post, I will respond to this question and explain the characteristics used to identify a molecule’s polarity.

Is C2H4 polar or nonpolar, then? Because of its symmetrical (linear) geometrical shape, ethylene (C2H4) is nonpolar in nature. Another reason is that the hydrogen-carbon bonds are nonpolar because their electronegativity is virtually identical. As a result, the dipole moment of the Ethylene molecule is zero.

The gas ethylene is flammable. It has a musky odour and is colourless in appearance. Ethene is the IUPAC term for ethylene.

Dimitry Neljubow, a Russian scientist, was the first to discover it in 1901.

It is the most basic of the alkene family’s hydrocarbons. It is widely utilised in the chemical industry. Its main product is used in the production of polyethylene, also known as plastic.

A polymer made up of ethylene molecules is known as polyethylene plastic.

The molecular structure of the ethylene molecule is made up of two carbon atoms and four hydrogen atoms.

A double bond connects both carbon atoms covalently. And hydrogen atoms are linked to carbon atoms by a single covalent bond.

The C2H4 molecule has a molecular mass of 28.054 gmol1. It is possible to compute it as follows:

28.054 gmol1 = 2 * 12 (Mol mass of C) + 4 * 1 (Mol mass of H) = Mol mass of C2H4.

In terms of carbon atoms, the molecule has a linear form. Nonpolar molecules are frequently found in linear compounds.

The strength with which an atom attracts the bound electron pair towards it is known as its electronegativity. It is a crucial factor in determining a molecule’s polarity.

Carbon has an electronegativity of 2.55 and hydrogen has an electronegativity of 2.2, making the C-H bond nonpolar due to the nearly same electronegativity of both atoms.

What Is the Difference Between Polar and Nonpolar Molecules?

Interatomic forces, such as metallic bonds, hydrogen bonds, ionic bonds, and covalent bonds, bind the molecules together.

Among the above bond forces, ionic and covalent bonds are the most powerful.

The covalent bond is a type of bond that involves the sharing of electrons between atoms in order to keep them stable. Bonded electron pairs are another name for these electrons.

Single (one electron pair), double (two electron pairs), and triple (three electron pairs) bonds are all possible.

Polar Molecules: A polar molecule is one that has a non-uniform charge distribution over its surface.

The dipole moment of these molecules is not zero. The dipole is formed by multiplying the charge by the distance between the positive and negative charge centres.

If the electronegativity of both atoms in a polar covalent bond differs, the bond is said to be polar.

NF3, NCl3, and H2O are only a few examples of polar chemicals. You can look into the explanation for NF3’s polarity.

Nonpolar Molecules: Nonpolar molecules are those that have a homogeneous charge distribution over their surface.

The dipole moment of these molecules is zero. In addition, the form of nonpolar molecules is usually symmetric.

The electronegativity of the atoms in a nonpolar covalent link is equivalent. BeCl2 and SF6 are two examples of such compounds. You can look into the reason behind BeCl2’s non-polarity.

C2H4 is a nonpolar molecule for a reason.

Ethylene is made up of two carbon atoms and four hydrogen atoms. The carbon-carbon bond is a double covalent bond, meaning it involves the sharing of two electron pairs.

Carbon has four valence electrons, while hydrogen has one. Both carbon atoms share two electrons, as well as two electrons from the two hydrogen atoms that are covalently bonded to carbon atoms.

As a result, the octets of both carbon and hydrogen are completed, resulting in the neutral molecule C2H4.

Carbon(2.55) and hydrogen(2.2) have approximately identical electronegativity, resulting in a nonpolar C-H bond.

The molecule is symmetrical and has a linear structure. As a result, the entire molecule retains its nonpolar character.

C2H4 molecules have no dipole moment because they are nonpolar.

Factors that influence a molecule’s polarity

Electronegativity: An atom’s electronegativity is a measurement of how strong it is in attracting shared bound electron pairs to its side.

The atom with the higher electronegativity attracts the bound electrons closer to it, gaining a partial negative charge, whereas the other atom obtains a partial positive charge.

When the electronegativity of two atoms making a molecule differs, the molecule is polar.

As a result, the molecule generates two poles (positive and negative).

A molecule’s polarity is proportional to the difference in electronegativity between its atoms.

The dipole moment of a molecule is the value of the polarity measure of the molecule.

A molecule’s polarity is proportional to its dipole. Its SI unit is the Debye, which is represented by the letter D.

It is the product of the charge on atoms and the distance between the centres of positive and negative charge in technical terms.

Q * R = D

Geometrical shape: The geometrical shape of a molecule is a key feature for determining its polarity.

Asymmetrically shaped molecules are normally nonpolar, whereas symmetrically structured molecules are polar.

Note that if nonpolar molecules contain polar bonds, the polarity of these bonds cancels out due to the symmetric form of the molecule.

The geometrical molecular structure of ethylene is shown below.

C2H4’s Characteristics

At normal temperature, ethylene is a colourless gas with a musky odour.

It is naturally flammable.

This substance has a melting point of 169.2 °C (272.6 °F) and a boiling point of 103.7 °C (154.7 °F).

This gas has a density of 1.178 kg/m3 at 15 degrees Celsius.

It has a solubility of 0.131 mg/mL in water at 25°C.

C2H4’s Applications

It is mostly utilised in the making of plastic (polyethylene), which is a polymer made up of C2H4 molecules arranged in a sequence.

It’s also utilised to halogenate substances in a variety of chemical processes.

90% of ethylene is used to make polyethylene, ethylene dichloride, ethylene oxide, and ethylbenzene in the United States and Europe.

Ethylene is oxidised to produce ethylene oxide, which is then utilised as a raw material for detergents and surfactants.


Ethylene (C2H4) is a molecule having two carbon atoms connected by a double bond (C=C). Because of their virtually identical electronegativity, the C-H bond is similarly nonpolar.

As a result, the molecule as a whole is nonpolar.

So, if you have any queries on C2H4’s non-polarity, please post them in the comments area. We’ll get back to you as soon as we can.

Read more: Is Alcohol Acidic or Alkaline in pH? 

Misha Khatri
Misha Khatri is an emeritus professor in the University of Notre Dame's Department of Chemistry and Biochemistry. He graduated from Northern Illinois University with a BSc in Chemistry and Mathematics and a PhD in Physical Analytical Chemistry from the University of Utah.


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