Is HCl a polar or nonpolar substance?

Hydrochloric acid is a chemical compound that is made up of inorganic elements. It has a colourless appearance and is used in laboratories to make aqueous-based solutions. It has a strong odour about it. Many students may be unsure whether or not HCl is polar. I shall explain the notion of polarity, as well as its qualities and applications, in this essay.

Is HCl polar or nonpolar, then? Because chlorine is more electronegative than hydrogen, it draws the bound electron pair somewhat closer to it and obtains a partial negative charge, whereas hydrogen gains a partial positive charge. HCl (hydrochloric acid) is a polar molecule. 1.03 D is found to be the dipole moment of HCl.

Hydrochloric acid is a white liquid with a strong odour. It is commonly used in chemistry laboratories at high schools and universities in the form of an aqueous solution.

When present in high concentrations, this chemical exists as a liquid and also produces vapours.

Hydrochloric acid has a molecular mass of 36.46 g/mol. It can be calculated using the formula:

Mol mass of HCl = 1* (mol mass of H) + 1* 35.5 (mol mass of Cl) = 36.46 g/mol

When it comes to the chemical makeup of hydrochloric acid, it is made up of one hydrogen molecule and one chlorine molecule.

The geometrical shape generated by a diatomic molecule is linear.

It’s a chemical substance that’s used a lot. Alchemist Jabir ibn Hayyan found it about 800 AD.

Hydrogen has a 2.2 D electronegativity, while chlorine has a 3.16 D electronegativity.

Because the chlorine atom is more electronegative, it draws the bound electron pair with greater force and develops a partial negative charge.

As a result, the hydrogen atom obtains a partial positive charge and takes on the role of a positive pole.

Why is HCl classified as a polar molecule?

The atoms hydrogen and chlorine make up hydrochloric acid. The electronegativity of both of them is noticeably different.

Chlorine has a higher electronegative potential than hydrogen. And it should go without saying that a more electronegative atom attracts the electron bond pair slightly more.

As a result, the chlorine atom obtains a substantially negative charge, becoming the negative pole, whereas the hydrogen atom gains a relatively positive charge, becoming the positive pole.

Two poles (positive and negative) are formed throughout a molecule in this manner. And it turns out that the molecule is polar.

A polar molecule’s dipole moment is always non-zero. The dipole moment of HCl is also 1.03 D. The dipole’s orientation is towards the chlorine atom (H->Cl).

The term “dipole moment” refers to a vector quantity. It has both a magnitude and a direction to it.

Molecules that are polar and those that are nonpolar

The properties of the molecules are determined by a number of variables. A molecule’s characteristics are determined by chemical bonding between its atoms and the properties of the atoms that make it up.

The electronegativity of atoms and the presence of covalent bonds across a molecule can influence whether a molecule is polar or not.

Let’s look at the distinctions between the two sorts of molecules.

Polar molecules have an unequal charge distribution across their atoms, whereas nonpolar molecules have an equal charge distribution across their atoms.

The dipole moment is a measurement of a molecule’s polarity. The dipole moment of a nonpolar molecule is always 0 D, but the dipole moment of polar molecules is non zero.

The polar molecule’s geometrical shape is deformed or bent, resulting in a non-uniform charge distribution.

Nonpolar molecules, on the other hand, have symmetrical shapes.

BrF3, OF2, and other polar compounds are examples. You can look into the explanation for BrF3’s polarity.

Cl2+ and No2+ are examples of nonpolar compounds. You can look into the reason behind NO2non-polarity. +’s

The important parameters that define a molecule’s polarity

Electronegativity is a concept that describes how a charge is distributed on an atom. A polar chemical bond is formed by two atoms with different electronegativity.

This is due to the fact that a more electronegative atom attracts the charge across its side and becomes a negative pole, while another atom becomes a positive pole in exchange.

The bigger the difference in electronegativity between the two atoms, the more polar the molecule.

The phrase “dipole moment” is used to describe how the polarity of a molecule is measured. A molecule’s polarity is proportional to the value of its dipole.

The product of the charge and the distance between the centres of positive and negative charges is the dipole moment.

The HCl molecule has a dipole moment of 1.03 D, which points in the direction of the chlorine atom.

Nonpolar molecules such as chlorine gas (Cl2) and oxygen gas (O2) have a 0 D dipole moment.

Geometrical shape: the shape of a molecule is also a major factor in determining whether or not it is polar. The nonpolar characteristic of the symmetrical structural molecule is commonly noticed.

These molecules have an identical charge distribution on all of their atoms, making them nonpolar overall.

The charge distribution on the atoms of polar molecules is uneven due to their deformed forms. The atoms have an uneven charge distribution.

You should read the HCl lewis structure and geometrical structure for additional information.

The 3D geometrical structure of the HCl molecule is shown here.

HCl’s properties

At typical temperatures and pressures, hydrochloric acid occurs in a liquid state with a distinct odour.

The physical properties of this acid change depending on how much HCl acid is present in aqueous solution.

At a temperature of 108.6 °C, hydrochloric acid is a mixture of HCl acid and water with a concentration of 20.2 percent HCl.

It is regarded as a powerful acid.

It’s a monoprotic molecule, meaning it can only release one proton at a time.

With a ph value of 1 to 2, it is also secreted in the intensive for the digestive system.

HCl’s Applications

It’s employed in the manufacture of Organic Compounds.

It’s extensively used to get rid of spots on metals.

The purification of table salt is also accomplished with this acid.

It’s also commonly employed in the oil industry.


Hydrochloric acid is a diatomic molecule, which means it has two atoms (hydrogen and chlorine). Because chlorine is more electronegative, it draws the bound electron pair to its side and gives it a partial negative charge.

The positive pole is hydrogen, whereas the negative pole is chlorine. The connection between H and Cl becomes polar due to the difference in electronegativity.

The polarity of the HCl molecule is due to these factors.

So, if you have any questions on the polarity series of various molecules, including those covered in my prior articles, please post them in the comments section. We’ll get back to you as soon as we can.

Read more: Is SiO2 a polar or nonpolar substance?

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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