IF5 is a POLAR molecule.
And how can you say that IF5 is a polar molecule?
Want to know the reason?
Let’s dive into it!
IF5 is a POLAR molecule because the I-F bonds present in the molecule are polar and it has asymmetric geometry which causes the partial positive (ẟ+) and partial negative (ẟ-) charge to appear on the molecule. These ẟ+ and ẟ- charges are responsible to make the entire IF5 molecule polar.
Let me explain this in detail with the help of IF5 lewis structure and its 3D geometry.
Why is IF5 a Polar molecule? (Explained in 3 Steps)
IF5 is a polar molecule because it has poles of partial positive charge (ẟ+) and partial negative charge (ẟ-) on it.
Let me explain this to you in 3 steps!
Step #1: Draw the lewis structure
Here is a skeleton of IF5 lewis structure and it contains five I-F bonds.
(Note: If you want to know the steps of drawing the IF5 lewis dot structure, then visit this article: IF5 lewis structure, Or you can also watch this short 2 minute video).
So from the above diagram we have come to know that the IF5 molecule has five I-F bonds.
Now in the next step we have to check whether these I-F bonds are polar or nonpolar.
And we also have to check the molecular geometry of IF5.
Step #2: Check whether individual bonds are polar or nonpolar
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 IF5 molecule. It has five I-F bonds.
You can see the electronegativity values of Iodine (I) and Fluorine (F) atoms from the periodic table given below.
From the above image;
Now let’s see the polarity of each bond.
For I-F bond;
The electronegativity difference (ΔEN) = 3.98 – 2.66 = 1.32
This value lies between 0.4 to 1.7, which indicates that the bond between Iodine (I) and Fluorine (F) is polar.
Hence, the I-F bonds are polar covalent bond.
You can see in the above image that because of higher electronegativity of Fluorine atom, the partial positive charge (ẟ+) appears on the Iodine atom (I) and partial negative charge (ẟ-) appears on the Fluorine atoms (F).
But wait, we also have to look at the molecular geometry of IF5 to know whether it has a symmetric shape or not.
Step #3: Check whether the molecule is symmetric or not
Have a look at this 3D structure of IF5. The Iodine atom (I) is at the center and it is surrounded by 5 Fluorine atoms (F).
It also has one lone pair on the Iodine atom (I).
Due to the lone pair on the iodine atom (I), its molecular geometry becomes asymmetric.
Because of this, there are positive and negative poles of charges on the overall molecule of IF5.
Hence, the IF5 molecule is a polar molecule.
I hope you have understood the reason behind the polar nature of IF5 molecule.
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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