SO2 (Sulfur dioxide) is a covalent (polar covalent) compound because when one nonmetal combines with another nonmetal, it usually forms a covalent compound. Here, S is a nonmetal and O is also a nonmetal. So when they combine, it forms a covalent compound.
Well, now you have got to know that SO2 is a covalent compound, but let me explain the in-depth reason why SO2 is a covalent compound.
If you are a visual learner like me, then here is a short one minute video for you.
Why is SO2 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 SO2, the S atom is a nonmetal and the O atom is also a nonmetal.
Hence the bond between them is a covalent bond.
Is SO2 polar covalent or nonpolar covalent?
In order to know whether SO2 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 Sulfur and Oxygen are mentioned below. (You can see the electronegativity of all the elements from this electronegativity chart).
- Electronegativity of Sulfur (S) = 2.58
- Electronegativity of Oxygen (O) = 3.44
So for SO2, the electronegativity difference (ΔEN) = 3.44 – 2.58 = 0.86
This value lies between 0.4 to 1.7, which indicates that the bond between Sulfur (S) and Oxygen (O) is polar covalent bond.
But the SO2 molecule has 1 lone pair which results in an asymmetric shape of the entire SO2 molecule.
Because of this asymmetric shape there are positive and negative poles of charges on the overall molecule of SO2.
Hence, SO2 is a polar covalent molecule.
I hope you have understood the reason why SO2 is a polar covalent compound.
Check out other compounds to see whether they are ionic or covalent;
Is MgO (Magnesium oxide) Ionic or Covalent?
Is CCl4 (Carbon tetrachloride) Ionic or Covalent?
Is CaO Ionic or Covalent?
Is KCl (Potassium chloride) Ionic or Covalent?
Is O2 Ionic or Covalent?
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