Hydrogen chloride or HCl is a covalent (polar covalent) compound because when one nonmetal combines with another nonmetal, it usually forms a covalent compound. Here, H is a nonmetal and Cl is also a nonmetal. So when they combine, it forms a covalent compound.
Well, now you have got to know that Hydrogen chloride (HCl) is a covalent compound, but let me explain the in-depth reason why HCl is a covalent compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is HCl a Covalent compound?
As mentioned above, you can simply remember that when the nonmetal combines with another nonmetal, the bond between them is a covalent bond.
Here in HCl, the H atom is a nonmetal and the Cl atom is also a nonmetal.
Hence the bond between them is a covalent bond.
How does the covalent bond form between H and Cl?
In HCl, there are two atoms;
H and Cl.
About Hydrogen (H):
Hydrogen atom have 1 electron.
It has only 1 orbit and there is only 1 electron in this orbit.
Now in order to achieve a stable duplet, the Hydrogen atom needs 1 more electron.
Hence during the chemical reaction, the Hydrogen atom will gain 1 electron from the combining atom to form a stable duplet.
About Chlorine (Cl):
Chlorine atom have 17 electrons.
The electrons arrangement in Chlorine (Cl) is 2, 8, 7.
So the outermost orbit of Chlorine atom has 7 electrons.
Now in order to achieve a stable octet, the Chlorine atom needs 1 more electron.
Hence during the chemical reaction, the Chlorine atom will gain 1 electron from the combining atom to form a stable octet.
What happens when H and Cl combine?
When H and Cl combine with each other, the Hydrogen atom and Chlorine atom mutually share their 1-1 electrons with each other.
Because of this the hydrogen atom will have 2 electrons in its outermost orbit and similarly the chlorine atom will also have 8 electrons in its outermost orbit.
As a result, the hydrogen atom will have a stable duplet and the chlorine atom will have a stable octet.
And finally, as the bond formed between the hydrogen and chlorine is due to the mutual sharing of electrons, it is considered a covalent bond.
Thus, HCl is a covalent compound.
Is HCl polar covalent or nonpolar covalent?
In order to know whether Hydrogen chloride (HCl) is a polar covalent molecule or nonpolar covalent molecule, we have to check the electronegativity difference of the combining atoms.
If the electronegativity difference (ΔEN) is less than 0.4, then the bond is nonpolar covalent bond.
If the electronegativity difference (ΔEN) is between 0.4 to 1.7, then the bond is polar covalent bond.[1][2][3][4]
Now the electronegativity of Hydrogen and Chlorine are mentioned below. (You can see the electronegativity of all the elements from this electronegativity chart).
- Electronegativity of Hydrogen (H) = 2.2
- Electronegativity of Chlorine (Cl) = 3.16
So for HCl, the electronegativity difference (ΔEN) = 3.16 – 2.2 = 0.96
This value lies between 0.4 to 1.7, which indicates that the bond between Hydrogen (H) and Chlorine (Cl) is polar covalent bond.
Hence, Hydrogen chloride (HCl) is a polar covalent molecule.
I hope you have understood the reason why HCl is a polar covalent compound.
Check out other compounds to see whether they are ionic or covalent;
Is CaCl2 (Calcium chloride) Ionic or Covalent?
Is NH3 (Ammonia) Ionic or Covalent?
Is CH4 (Methane) Ionic or Covalent?
Is MgCl2 (Magnesium chloride) Ionic or Covalent?
Is SO2 (Sulfur dioxide) Ionic or Covalent?
Jay is an educator and has helped more than 100,000 students in their studies by providing simple and easy explanations on different science-related topics. With a desire to make learning accessible for everyone, he founded Knords Learning, an online learning platform that provides students with easily understandable explanations.
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