NO3- is a NONPOLAR ion.
And how can you say that NO3- is a nonpolar ion?
Want to know the reason?
Let’s dive into it!
NO3- (or Nitrate ion) is a NONPOLAR ion because all the three bonds (one N=O and two N-O bonds) are equidistant and NO3- has symmetrical geometry.
Let me explain this in detail with the help of NO3- lewis structure and its 3D geometry.
Why is NO3- a Nonpolar ion? (Explained in 2 Steps)
NO3- is a nonpolar ion because it does not have any pole of positive charge and negative charge on it.
Let me explain this to you in just 2 steps!
Step #1: Draw the lewis structure
Here is a skeleton of NO3- lewis structure and it contains three Nitrogen-Oxygen bonds.
(Note: If you want to know the steps of drawing the NO3- lewis dot structure, then visit this article: NO3- lewis structure, Or you can also watch this short 2 minute video).
So from the above diagram we have come to know that the NO3- ion has three Nitrogen-Oxygen bonds.
Now in the next step we have to check whether these three Nitrogen-Oxygen bonds are polar or nonpolar.
And we also have to check the molecular geometry of NO3- ion.
Step #2: Check the bond polarity and molecular geometry
The chemical bonds can be either nonpolar, polar or ionic depending on the difference of the electronegativity values (ΔEN) between the two atoms.
Have a look at the above image.
- 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.
- If the electronegativity difference (ΔEN) is greater than 1.7, then the bond is an ionic bond.     
Now let’s come to the example of NO3- ion. It has three Nitrogen-Oxygen bonds.
You can see the electronegativity values of Nitrogen (N) and Oxygen(O) atoms from the periodic table given below.
From the above image;
Now let’s see the polarity of each bond.
For Nitrogen-Oxygen bonds;
The electronegativity difference (ΔEN) = 3.44 – 3.04 = 0.4
Now this value is exactly between the range of polar and nonpolar bonds, so we cannot perfectly say whether the Nitrogen-Oxygen bonds are polar or nonpolar.
In some textbooks, you may find some different range of ΔEN, but if we consider the above mentioned range for ΔEN, then we can say that the Nitrogen-Oxygen bonds can be either highly nonpolar or very less polar.
But let’s keep this discussion aside.
Because we also have to look at the molecular geometry of NO3- ion to know whether it has a symmetric shape or not.
Have a look at this 3D structure of NO3- ion. You can see that the structure of NO3- is symmetrical.
The nitrogen atom is at the center and it is surrounded by 3 oxygen atoms which are equidistant as well as at equal angles.
As the NO3- ion has a symmetrical geometry, there are no positive and negative poles of charges on the overall NO3- ion.
Hence, the NO3- ion is a nonpolar ion.
I hope you have understood the reason behind the nonpolar nature of NO3- ion.
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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