Best Overview: Is HCl polar or nonpolar [#1]

Hydrochloric acid(HCl) is the common acid available in chemical laboratories. Hydrogen chloride has the chemical formula HCl. Hydrogen is the first element in the periodic table and chlorine comes in the halogen family. Another name for this chemical compound is hydrochloric acid. Students used to ask “Is HCl polar or nonpolar?”, “HCl Lewis Structure”, “HCl molecular geometry”, “HCl bond angle”, and “HCl polarity”. In this blog post, we are going to discuss the polarity of HCl in a detailed manner.

HCl is commonly appearing at ordinary temperatures and pressures, it exists as a colorless liquid with a transparent texture, containing 37.5 percent HCl by weight with respect to water. HCl contains one hydrogen atom and one chlorine atom. Hydrogen chloride(HCl) is corrosive to biological tissue and metals, and it can also cause huge damage when it comes into contact with wood, cotton, and other materials. The chlorine atom stays one terminal of the molecule and the remaining one hydrogen atom in another terminal. “Is HCl polar or nonpolar?”, to answer this question, we need a detailed analysis of the polarity of the HCl molecule.

Because of the linear form of hydrogen chloride(HCl). Chlorine has atomic number 17 in the modern periodic table and seven outermost valence shell electrons. It comes under the halogen family group as the second element in the periodic table. Similarly, hydrogen has atomic numbers one and one outermost valence shell electron.

HCl molecule is formed by elements of the hydrogen and halogen family group in the periodic table. When concentrated HCl acid is exposed to air, it absorbs water quickly and produces white vapors that have a distinct odor, irritate the skin, and are toxic to breathe. Hydrogen Chloride (HCl) can generate dilute acid when it diluted with water and acts as a chemical reagent in many chemical reactions.

Is HCl polar or nonpolar, then? HCl(hydrogen chloride) is polar due to unequal electronegativity values of atoms in the HCl molecule. Second, the difference in electronegativity between hydrogen and chlorine atoms causes the H-Cl bonds to become polar, causing the entire molecule to become polar as well, resulting in a net dipole moment of the HCl molecule is 1.08 D. This is less than the HBr dipole moment.

Best Overview: Is HCl polar or nonpolar

Preparation of HCl

Hydrogen Chloride(HCl) is a colorless liquid with a strong intense odor. It is prepared primarily through the acidification of chloride salt. It is the heterogeneous reaction, potassium chloride in the solid phase and concentrated sulfuric acid in the liquid phase. Initially, potassium chloride reacted with concentrated sulfuric acid formed the hydrogen chloride(HCl). This acidification of the chloride salt reaction step is exothermic in nature.

The chemical equation of acidification of chloride salt exothermic reaction is shown below.

KCl + H2SO4 ——Exothermic—-> KHSO4 + HCl

Preparation of hydrogen chloride(HCl)

HCl Molar Mass Calculation

HCl has a molecular mass of 36.458 g/mol, which may be computed as follows.

Mol mass of HCl = 1 * 35(atomic mass of Cl) + 1* 1(atomic mass of H) = 36.458 g/mol.

Hydrogen chloride(HCl) molar mass calculation

The chemical composition of the hydrogen chloride molecule is one chlorine atom and one hydrogen atom in the linear structure form.

Key Points To Consider When Determining The Polarity of HCl Molecule

When attempting to determine the polarity of the HCl molecule, a three-step procedure can be used. The first stage is to sketch the HCl molecule’s Lewis structure; the second step is to determine the HCl molecule’s geometry, and the final step is to determine the HCl molecule’s bond polarities (dipole moment) and add them together.

Drawing the HCl Lewis structure is a method of representing a molecule using a diagram that shows the number of valence electrons and bond electron pairs in the HCl molecule. The geometry of the HCl molecule can then be determined using the Valence Shell Electron Pair Repulsion Theory (VSEPR Theory), which stipulates that molecules will adopt an HCl geometrical formation that the electrons have from one another.

Finally, you must calculate the H-Cl bond’s strength by adding their bond polarities (dipole moment properties of Hcl molecule). The hydrogen-chlorine bonds in hydrogen chloride(HCl), for example, are polarised toward the more electronegative chlorine, and because both bonds have the same magnitude, their sum is non zero due to lone pair of HCl molecule, and the HCl molecule is categorized as a polar.

The molecule of hydrogen chloride (diatomic) is angled at 180 degrees(linear structure) and has a difference in electronegativity value of hydrogen and chlorine atom, with hydrogen’s pull being much lower than that of chlorine. As a result, a persistent dipole moment exists. The unequal charge distribution of negative and positive charges causes the dipole moment of HCl molecule.

HCl Lewis Structure: Is HCl polar or nonpolar?

One terminal atom is chlorine, which is flanked by one hydrogen atom. A chlorine atom contains seven outermost valence electrons, which means it contains seven electrons in its outermost shell, whereas hydrogen has one outermost electron. A chlorine atom is required one electron to complete the octet of chlorine atoms. If you want to know about the octet rule of the chlorine atom, please see in our previous post.

As a result of this, both one chlorine atom forms covalent bonds with the hydrogen atom, leaving the two atoms with a linear structure. The bond pairs of H-Cl are not repelled by the lone pairs on the chlorine atom. According to VSEPR theory, no electronic repulsion causes the HCl molecule’s shape to linear structure, similar to that of the CS2, HBr, and NO2+ ion.

The bond pair forces both H-Cl bond linear and polarize in nature, resulting in the linear form of the HCl molecule. Because they generate no electrical repulsion among the HCl molecule, no lone pairs have deformed shapes of the HCl molecule.

Electronegative difference calculation HCl:

When it comes to the electronegativity value of the HCl molecule, chlorine has an electronegativity of 3.16, while hydrogen has an electronegativity of 2.2. The electronegativity difference can be calculated by the following method.

Electronegativity value of chlorine = 3.16

Electronegativity value of hydrogen = 2.2

Difference of electronegativity value between chlorine and hydrogen = 3.16 – 2.2=0.96

Electronegativity difference calculation of HCl molecule

The H-Cl bond of the HCl molecule becomes polar in nature due to this difference in electronegativity value. The power with which an atom can attract bound electron pairs towards its side is known as the electronegativity of the atom.

As a result of this, the dipole moment of the H-Cl bond is non zero, and the dipoles of the H-Cl bond are not negated due to the linear structure. The total dipole moment of the HCl molecule is calculated to be 1.08 D. Chlorine atom receives a partial negative charge on it, while hydrogen atom receives a partial positive charge on it.

HCl molecule’s electron dot structure is also known as HCl Lewis structure. It determines the number of outermost valence electrons and the electrons involved in the formation of the HCl molecule’s bonds. When discussing the Lewis structure of the HCl molecule, it is necessary to understand the outermost valence electrons of HCl.

The hydrogen atom is on one terminal of the HCl molecule, with one electron in its outermost valence electron shell, while the chlorine atom is the outermost valence electron shell, with seven electrons and one electron missing in the shell to complete its octet.

As a result of this above explanation, the HCl molecule contains a total of 8 valence electrons. The one hydrogen atom establishes covalent connections with the chlorine atom, leaving the HCl molecule with a linear structure form.

The lone pairs of chlorine atoms cause no repulsion with H-Cl bond pairs, causing the H-Cl bonds to form a linear structure and the shape of the molecules to like that of the CS2, HBr, and NO2+ (nitronium ion) molecule. The H-Cl bond(diatomic molecule) has a bond angle of roughly 180 degrees(linear structure). H-Cl bond has a bond length of 128 pm (picometer).

To sketch the HCl Lewis structure by following these instructions:

Step-1: Determine the total number of outermost valence shell electrons in the HCl molecule. The first step is to figure out how many outermost valence shell electrons there are in the HCl Lewis structure. A valence electron is one of an atom’s outermost shell electrons. In the HCl Lewis structure diagram, it is represented by dots. The chlorine atom of the HCl molecule can be represented as follows.

Look for the periodic group of each atom in HCl to determine its valence electron. Hydrogen and chlorine are both members of the hydrogen and halogen family, which is the 1st and 17th groups in the periodic table respectively. Chlorine and hydrogen have seven and one valence electrons in their outermost shell respectively.

Because hydrogen and chlorine belong to the hydrogen and halogen family group in the periodic table, their valence electrons are one and seven respectively.

Total outermost valence shell electron of the chlorine atom in HCl = 7

Total outermost valence shell electron of the hydrogen atom in HCl= 1

The HCl molecule has one terminal hydrogen atom and one chlorine atom. Then the total outermost valence shell electrons can be calculated as follows

∴ Total outermost valence shell electrons available for HCl Lewis structure( dot structure) = 7 + 1*1 = 8 valence electrons  in HCl   

calculation of total valence electron of HCl molecule

Step-2: The HCl molecule contains only two atoms. Locate the atom with the least electronegative charge and place it in the two terminals of the HCl molecular geometry. In this phase, we’ll select the least electronegative atom in the HCl molecule to place in the HCl Lewis structure diagram’s one terminal. In the periodic table, the electronegativity value increases in order from left to right and decreases in order from top to bottom in periodic groups.

As a result, chlorine is the third atom in the halogen family group in the periodic table. Hydrogen comes first in the hydrogen family group. A hydrogen atom has a lower electronegative value than a chlorine atom. Furthermore, because chlorine is the most electronegative element in chemistry, it can be another terminal atom in a HCl Lewis structure diagram. As a result of this, place hydrogen at one terminal of the HCl Lewis structure, with a chlorine atom in another terminal of a linear molecule.

Step-3: Use one single bond (H-Cl) to connect the outside and core atoms in the HCl molecule. Connect the outside atom (chlorine) to the other terminal atom (hydrogen) with one single bond in this stage.

Count how many outermost valence shell electrons we’ve used so far in the HCl structure. Because each hydrogen atom is connected to a chlorine atom by one single (H-Cl) bond, each connection contains two electrons. Those are called bond pairs.

So, from the total of 8 valence electrons available for the HCl Lewis structure, we employed 2 electrons for one single (H-Cl) bond in the HCl molecule. There are still 6 valence electrons left in the HCl molecule. Where do we need to place them in HCl molecular geometry?

Step-4: Starting with the terminal chlorine atoms in the HCl molecule, place the remaining valence electrons. We always start inserting valence electrons from the exterior atom first in the HCl Lewis structure diagram. As a result, first, wrap around the leftover valence electrons on the chlorine atom.

To complete its octet, chlorine requires 8 electrons in its outermost valence shell. With the help of a single bond, chlorine already shares one electron and another one from a hydrogen atom. Put 6 electrons around the terminal chlorine atom and you’re done with the chlorine in the HCl molecule.

In the HCl molecule structure above, we’ve put 6 electrons around the chlorine atom, represented by a dot. As the chlorine atom has 8 electrons in its outermost valence shell, the chlorine atom comfortably completes its octet stability in the HCl molecule.

Using the HCl Lewis structure, count how many outermost valence shell electrons have been consumed so far. In the HCl molecular structure, 8 electrons are represented as dot structure, whereas one single bond contains 2 electrons. As an outcome of the calculation, the outermost valence shell electrons are 6 + 2 = 8.

So far, we’ve used 8 of the total 8 outermost valence shell electrons available for the HCl Lewis structure. Chlorine is obeying the rule of the octet as 8 electrons around it. Place the six valence electrons around the chlorine center atom, which is acting as an octet stabilization in this case.Best Overview: Is HCl polar or nonpolar

What are HCl electron and molecular geometry?

HCl has a linear molecular geometry and like NO2+ ion electron geometry, according to the VSEPR theory. Because the terminal atom, chlorine, has one H-Cl bond with other terminal hydrogen atoms. In the same plane, the H-Cl bond forms a 180-degree angle. Because two atoms are in the same plane, they form a linear molecular shape.

At that plane, there are no lone pairs of electrons in the HCl molecule. It maintains the linear structural form after connecting the chlorine and hydrogen atoms to the linear form. The two atoms are located just opposite bond pairs in the linear molecular geometry. The two atoms of the HCl are just linear form and bond pair plane in the molecular geometry.

Because of the two atoms of the HCl molecule, it gives linear electron geometry. But the HCl molecular geometry is a linear form in nature. It is the asymmetrical geometry of the HCl molecule. That makes, HCl molecule is polar.

How to find HCl molecular geometry

  1. Determine the number of lone pairs on the HCl Lewis structure.
    We need to figure out how many lone pairs there are on the terminal chlorine atom of the HCl Lewis structure because the lone pairs on chlorine are primarily responsible for the HCl molecule geometry distortion.

Use the formula below to find the lone pair on the HCl molecule’s terminal chlorine atom.

L.P(Cl) = V.E(Cl) – N.A(Cl-H)/2


Lone pair on the terminal chlorine atom = L.P(Cl)

The core terminal chlorine atom’s valence electron = V.E(Cl)

Number of Cl-H bonds = N.A (Cl-H)

calculation for chlorine atom lone pair in HCl molecule

In the case of HCl, the terminal atom, chlorine, has seven outermost valence shell electrons and one hydrogen atom connected to it.

As a result of this, L.P(Cl) = (7 – 1)/2=3

The lone pair on the terminal chlorine atom of the HCl electron geometry structure is equal to three. It means, the terminal chlorine atom contains three lone pairs.

  1. Determine the number of HCl molecular hybridizations.
    How to find the hybridization of the HCl molecule?. Now we need to figure out what HCl’s molecular hybridization number is.

The formula of HCl molecular hybridization is as follows:

No. Hyb of HCl = N.A(Cl-H) + L.P(Cl)

No. Hy of HCl= the number of hybridizations of HCl

Number of H-Cl bonds = N.A (Cl-H)

Lone pair on the terminal chlorine atom = L.P(Cl)

Calculation for hybridization number for HCl molecule

chlorine, then, is a terminal atom with one hydrogen atom linked to it and three lone pairs in the HCl molecule. Then the number of hybridization of HCl (No. Hyb of HCl) can be calculated as follows

No. Hyb of HCl= 1+3 =4

The number of hybridization for HCl molecule is four. one S orbital, and three p orbitals combine together to form the sp3 hybridization. HCl molecule is SP3 hybridized.

3. Use VSEPR theory to determine HCl molecular geometry shape

When the VSEPR theory is utilized to calculate the shape of the HCl molecule, the AXN approach is typically used.

The AXN notation is as follows:

The terminal chlorine atom in the HCl molecule is denoted by the letter A.

The bound pairs (H-Cl) of electrons to the terminal atom are represented by X.

The lone pairs of electrons on the terminal chlorine atom are denoted by the letter N.

Notation for HCl molecular geometry

We know chlorineis the terminal atom with one bound (H-Cl) pairs of electrons and three lone pairs. because of the HCl Lewis structure. HCl has the general molecular geometry formula AXN3.

If the molecule has an AXN3 generic formula, the molecular geometry will be linear form and the electron geometry will be linear, according to the VSEPR theory.

Name of MoleculeHydrogen Chloride
Chemical molecular formulaHCl
Molecular geometry of HClLinear
Electron geometry of HClLinear
HybridizationSp³
Bond angle diatomic (H-Cl)180º degree
Total Valence electron for HCl8
The formal charge of HCl on chlorine0

How to calculate the formal charge in HCl Lewis Structure?

The formal charge on the terminal chlorine atom of the HCl molecule often represents the actual charge on that chlorine terminal atom. The formal charge will be found on the terminal chlorine atom of the HCl Lewis dot structure in the following calculation.

To calculate the formal charge on terminal chlorine atom of HCl molecule by using the following formula:

The formal charge on chlorine atom of HCl molecule= (V. E(Cl)– L.E(Cl) – 1/2(B.E))

V.E (Cl) = Valence electron in chlorine atom of HCl molecule

L.E(Cl) = Lone pairs of an electron in chlorine atom of HClmolecule.

B.E = Bond pair electron in Cl atom of HCl molecule

calculation of formal charge on chlorine atom in HCl molecule

We have 7 valence electrons, 6 lone pair electrons, and two bonding electrons in the chlorine terminal atom (one single bond attached to hydrogen) of the HCl molecule. Now put these value of the chlorine atom in the above formula

Formal charge on chlorine atom of HCl molecule = (7- 6-(2/2)) =0

The formal charge on terminal chlorine atom of HCl Lewis structure is zero.

Lewis structure of some other related post in this blog. See more detail by clicking on it, H2OBeCl2SF4NH3XeF4, BF3BrF3BrF5SO3SCl2SO3PCl3H2SNO2+, HBr, CS2, CH3F, SO2, and CH2Cl2 molecules.

Dipole moment of HCl

The dipole moment of the HCl molecule can assist us in determining the polarity’s strength. The polarity of any molecule is proportional to its dipole moment. Because the form of HCl is asymmetric. The dipole moment of HCl does not cancel each other as a result of this.

Dipole moment of HCl can be calculated as follows

D(H-Cl) = Q(H-Cl) * R(H-Cl)

D(H-Cl) = Dipole moment of H-Cl bond in HCl molecule

Q(H-Cl) = Charge distribution in Cl and H atom of HClmolecule

R(H-Cl)= Bond length of H-Cl bond in HCl molecule

Dipole moment calculation of HCl molecule

Net dipole moment of HCl molecule is 1.08 D.

Why is HCl a polar molecule?

Due to the existence of three lone pairs on the chlorine atom, the hydrogen Chloride (HCl) molecule has a linear geometrical form. According to the VSEPR hypothesis, lone pairs and bond pairs did not repel each other, causing the H-Cl bonds to form a linear molecular structure, resulting in a linear shaped molecule.

The dipole moment of H-Cl bonds does not cancel out as it does in asymmetric linear HCl molecules. HCl has a dipole moment of 1.08 D across the entire molecule. The formation of a polar molecule is caused by the geometrical asymmetrical structure and the difference in electronegativity value of atoms in the HCl molecule.

Because of the asymmetric shape of the HCl molecule, the charge is dispersed non-uniformly among the hydrogen and chlorine atoms, resulting in the formation of positive and negative terminal poles across the HCl molecule.

Properties of HCl molecule

The properties of HCl molecule are listed as follows

  • It has the appearance of a colorless liquid.
  • It dissolves easily in water and gives hydrochloric acid.
  • The HCl molecule has a density of roughly 1.18 g/ml.
  • The Hydrogen Chloride molecule’s molecular mass is calculated to be 36.458 g/mol.
  • HCl has a melting point of – 114.2 °C.
  • HCl has a predicted boiling point of roughly -85.5 °C.

Uses of HCl molecule

HCl molecule uses are listed as follows

  • It’s commonly employed as a catalyst and reagent in a wide range of organic processes.
  • Because anhydrous hydrochloric acid is a hazardous and corrosive substance, it is transported in glass line cylinders.
  • It also serves as a chlorinating agent for different compounds.
  • It is widely used in the manufacture and chemical laboratories.

Conclusion

Due to the existence of three lone pairs on the terminal chlorine atom, Hydrogen Chloride has a linear structural form. With a bond angle(H-Cl) of roughly 180 degrees, the chlorine atom is the one terminal, another side by one hydrogen atom. Its electron geometry is linear. The molecular hybridization of the HCl molecule is sp3.

Because of the difference in electronegativity between hydrogen and chlorine atoms, the H-Cl bond is polar, and the entire molecule has a dipole moment of 1.08 D. This is due to the unsymmetrical structure of the HCl molecule with three lone pairs in a terminal chlorine atom. The HCl molecule is polar due to its asymmetric geometrical shape and unequal electronegativity of its atoms.

If you have any queries and doubts about this HCl polarity post, please leave your question in the comment section. We shall reply back on it as soon as possible.

FAQ on “Is HCl polar or nonpolar”

Is HCl a polar or nonpolar molecule?

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.

Is it true that HCl is symmetrical?

HCl is a polar molecule that is not symmetrical. As a result, it has two charged ends that are opposite each other.

Why is there no hybridization in HCl?

Because HCl is a linear diatomic molecule with a H atom and a Cl atom bound covalently, there is no hybridization. As a result, no additional stability is required.

Why does HCl have a dipole moment?

Because the hydrogen atom has a tiny positive charge and the chlorine atom has a slight negative charge, HCl molecules exhibit a dipole moment. A tiny dipole-dipole force of attraction exists between adjacent HCl molecules due to the force of attraction between oppositely charged particles.

The polarity of the molecules

The polarity of the molecules are listed as follows

Lewis Structure and Molecular Geometry

Lewis structure and molecular geometry of molecules are listed below

External Reference: “Is HCl polar or nonpolar

Information on Hydrochloric Acid (HCl)

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