Is CH2Cl2 Polar or Nonpolar? (And Why?)

Is CH2Cl2 Polar or Nonpolar

CH2Cl2 is a POLAR molecule.

But why? 

And how can you say that CH2Cl2 is a polar molecule?

Want to know the reason?
Let’s dive into it!

CH2Cl2 is a POLAR molecule because the C-Cl bonds present in the molecule are polar, 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 CH2Cl2 molecule polar.

Let me explain this in detail with the help of CH2Cl2 lewis structure and its 3D geometry.

Why is CH2Cl2 a Polar molecule? (Explained in 2 Steps)

CH2Cl2 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 2 steps!

Step #1: Draw the lewis structure

Here is a skeleton of CH2Cl2 lewis structure and it contains two C-H bonds and two C-Cl bonds.

Is CH2Cl2 Polar or Nonpolar

(Note: If you want to know the steps of drawing the CH2Cl2 lewis dot structure, then visit this article: CH2Cl2 lewis structure, Or you can also watch this short 2 minute video).

So from the above diagram we have come to know that the CH2Cl2 molecule has two C-H bonds and two C-Cl bonds.

Now in the next step we have to check whether these two C-H bonds and two C-Cl bonds are polar or nonpolar.

And we also have to check the molecular geometry of CH2Cl2.

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. [1] [2] [3] [4]

Now let’s come to the example of CH2Cl2 molecule. It has two C-H bonds and two C-Cl bonds.

You can see the electronegativity values of Carbon (C), Hydrogen (H) and Chlorine (Cl) atoms from the periodic table given below.

From the above image;

  • Electronegativity of Carbon (C) = 2.55 [5]
  • Electronegativity of Hydrogen (H) = 2.2 [6]
  • Electronegativity of Chlorine (Cl) = 3.16 [7]

Now let’s see the polarity of each bond.

For C-H bond;
The electronegativity difference (ΔEN) = 2.55 – 2.2 = 0.35 
This value is less than 0.4, which indicates that the bond between Carbon (C) and Hydrogen (H) is nonpolar.
Hence, each C-H bond is a nonpolar covalent bond.

For C-Cl bond;
The electronegativity difference (ΔEN) = 3.16 – 2.55 = 0.61
This value lies between 0.4 to 1.7, which indicates that the bond between Carbon (C) and Chlorine (Cl) is polar.
Hence, each C-Cl bond is a polar covalent bond.

Is CH2Cl2 Polar or Nonpolar

You can see in the above image that because of large electronegativity difference of Carbon and Chlorine atoms, the partial positive charge (ẟ+) appears on the Carbon atom (C) and partial negative charge (ẟ-) appears on the Chlorine atoms (Cl).

From this, you can easily get the idea that the CH2Cl2 molecule is a polar molecule.

But let’s also see its 3D molecular geometry for better understanding.

Is CH2Cl2 Polar or Nonpolar

Have a look at this 3D structure of CH2Cl2. The more electronegative chlorine atom (Cl) has a tendency to pull the shared electron pair towards itself, which results in partial positive charge on carbon atom (C) and partial negative charge on chlorine atoms (Cl).

Because of this, there are positive and negative poles of charges on the overall molecule of CH2Cl2.

Hence, the CH2Cl2 molecule is a polar molecule.

I hope you have understood the reason behind the polar nature of CH2Cl2 molecule.

See the polarity of other molecules to make your concepts clear:
Is N2 Polar or Nonpolar?
Is O2 Polar or Nonpolar?
Is SF4 Polar or Nonpolar?
Is SO3 Polar or Nonpolar?
Is PCl3 Polar or Nonpolar? 

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 learning platform that provides students with easily understandable explanations.

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