Is CO2 (Carbon dioxide) Ionic or Covalent? (And Why?)

Is CO2 (Carbon dioxide) Ionic or Covalent

CO2 (Carbon dioxide) is a covalent (nonpolar covalent) compound because when one nonmetal combines with another nonmetal, it usually forms a covalent compound. Here, C 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 CO2 is a covalent compound, but let me explain the in-depth reason why CO2 is a covalent compound.

If you are a visual learner like me, then here is a short one minute video for you.

Why is CO2 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 CO2, the C atom is a nonmetal and the O atom is also a nonmetal.

Hence the bond between them is a covalent bond.

How does the covalent bond form in CO2?

In CO2, there are two atoms;
C and O.

About Carbon (C):

Carbon atom have 6 electrons.

The electrons arrangement in Carbon (C) is 2, 4.

So the outermost orbit of Carbon atom has 4 electrons.

Now in order to achieve a stable octet, the Carbon atom needs 4 more electrons.

carbon

Hence during the chemical reaction, the Carbon atom will gain 4 electrons from the combining atom to form a stable octet.

About Oxygen (O):

Oxygen atom have 8 electrons.

The electrons arrangement in Oxygen (O) is 2, 6.

So the outermost orbit of Oxygen atom has 6 electrons.

Now in order to achieve a stable octet, the Oxygen atom needs 2 more electrons.

oxygen

Hence during the chemical reaction, the Oxygen atoms will gain 2 electrons from the combining atom to form a stable octet.

What happens when C and O combine?

When C and O combine with each other, the Carbon atom and Oxygen atoms mutually share their 2-2 electrons with each other.

Because of this the carbon atom will have 8 electrons in its outermost orbit and similarly the oxygen atom will also have 8 electrons in its outermost orbit.

co2

As a result, the carbon atom and oxygen atom will have a stable octet.

And finally, as the bond formed between the carbon and oxygen is due to the mutual sharing of electrons, it is considered a covalent bond.

Thus, CO2 is a covalent compound.

Is CO2 polar covalent or nonpolar covalent?

In order to know whether CO2 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 Carbon and Oxygen are mentioned below. (You can see the electronegativity of all the elements from this electronegativity chart).

  • Electronegativity of Carbon (C) = 2.55
  • Electronegativity of Oxygen (O) = 3.44

So for CO2, the electronegativity difference (ΔEN) = 3.44 – 2.55 = 0.89

This value lies between 0.4 to 1.7, which indicates that the bond between Carbon (C) and Oxygen (O) is polar covalent bond.

But if you look at the 3D structure of CO2, you can see that the structure of CO2 is symmetrical.

As both the bonds (C=O) are symmetrical and the CO2 molecule has a symmetrical geometry, their bond polarity gets canceled with each other.

co2

Hence, CO2 is a nonpolar covalent molecule.

I hope you have understood the reason why CO2 is a nonpolar covalent compound.

Check out other compounds to see whether they are ionic or covalent;
Is H2O (Water) Ionic or Covalent?
Is Hydrogen chloride (HCl) Ionic or Covalent?
Is CaCl2 (Calcium chloride) Ionic or Covalent?
Is NH3 (Ammonia) Ionic or Covalent?
Is CH4 (Methane) Ionic or Covalent? 

Author

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 chemistry learning platform that provides students with easily understandable explanations.

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