H2S 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 S is also a nonmetal. So when they combine, it forms a covalent compound.
Well, now you have got to know that H2S is a covalent compound, but let me explain the in-depth reason why H2S is a covalent compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is H2S 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 H2S, the H atom is a nonmetal and the S atom is also a nonmetal.
Hence the bond between them is a covalent bond.
How does the covalent bond form between H and S?
In H2S, there are two atoms;
H and S.
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 Sulfur (S):
Sulfur atom have 16 electrons.
The electron arrangement in Sulfur (S) is 2, 8, 6.
So the outermost orbit of Sulfur atom has 6 electrons.
Now in order to achieve a stable octet, the Sulfur atom needs 2 more electrons.
Hence during the chemical reaction, the Sulfur atom will gain 2 electrons from the combining atom to form a stable octet.
What happens when H and S combine?
When H and S combine with each other, the Hydrogen atoms and Sulfur 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 sulfur atom will also have 8 electrons in its outermost orbit.
As a result, the hydrogen atom will have a stable duplet and the sulfur atom will have a stable octet.
And finally, as the bond formed between the hydrogen and sulfur is due to the mutual sharing of electrons, it is considered a covalent bond.
Thus, H2S is a covalent compound.
Is H2S polar covalent or nonpolar covalent?
In order to know whether H2S 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 Sulfur are mentioned below. (You can see the electronegativity of all the elements from this electronegativity chart).
- Electronegativity of Hydrogen (H) = 2.2
- Electronegativity of Sulfur (S) = 2.58
So for H2S, the electronegativity difference (ΔEN) = 2.58 – 2.2 = 0.38
This value is less than 0.4, which indicates that the bond between Hydrogen (H) and Sulfur (S) is nonpolar.
But the H2S molecule has 2 lone pairs which results in an asymmetric shape of the entire H2S molecule.
Because of this asymmetric shape there are positive and negative poles of charges on the overall molecule of H2S.
Hence, H2S is a polar covalent molecule.
I hope you have understood the reason why H2S is a polar covalent compound.
Check out other compounds to see whether they are ionic or covalent;
Is NaBr Ionic or Covalent?
Is Na2O Ionic or Covalent?
Is CO Ionic or Covalent?
Is HF (Hydrogen fluoride) Ionic or Covalent?
Is CS2 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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