Why is CH2Cl2 polar?

[annemarielawrence]

Can someone explain to me why CH2Cl2 is polar? I drew out the lewis structure and I thought that the elements would cancel out each other's dipole moment but the book says that it's polar. Is it because of the hydrogens?

[Autumn Jackson Dis 1J]

CH2Cl2 is a tetrahedral shape, and even though in a drawn lewis structure the molecule can look "symmetrical", the actual shape of the molecule doesn't have any electron regions directly opposite of one another. So as soon as one atom or more is different from the rest, the molecule becomes polar.

[Kelly Bui 2I]

As said, CH2Cl2 is in a tetrahedral and may look symmetrical but Cl is the most electronegative atom in the molecule so there would be a larger dipole movement towards Cl. And due to these unequal dipole moments they do not cancel and make the molecule polar.

[Arjan G 2H]

Hi! So for CH2CL2, The molecule is polar because of its molecular structure and dipole moments. Because there are four bonding pairs surrounding the central atom, the shape of the molecule is going to be tetrahedral. So, one of the chlorine atoms is going to be above the central carbon atom, and the other three atoms are going to be surrounding it. This creates a dipole moment towards the chlorine atom, as it is more electronegative than hydrogen, making this molecule polar. I hope this helps!

[Amanda Pineda 3H]

Hi! So this is because the dipole moments of H and Cl are very different and therefore the 4 dipole moments do not cancel out. Chlorine is more electronegative than H so it's dipole moment will be much larger, causing the molecule to be polar.

[Katherine Li 1A]

The Lewis structure is a little misleading here, because it suggests that CH2Cl2 is square planar, with polar bonds that can cancel out. However, make sure to keep in mind the molecular shape instead! CH2Cl2 is actually tetrahedral, which means all the bond angles are about 109.5 degrees. In this model, if only two of the bonds are polar, they won't be directly across from each other, so they wouldn't be able to cancel out. That's why CH2Cl2 would still be polar.

[Connor_Olsen_2K]

In a tetrahedral it is impossible to set it up in a way in which the CL single bonds cancel.

[Claire_Sabol_2G]

Molecules arranged in a tetrahedral shape will only be nonpolar if all of the atoms surrounding the central atom are the same. However, because Cl is the more electronegative atom in this case, there will be a dipole moment towards this atom. Looking up the 3D-model of a tetrahedral molecule may help you to visualize why this atom won't be non-polar!

[Yajing Feng 2J]

CH2Cl2 is arranged in a tetrahedral shape so the dipole moments don't actually cancel out.

[Hope Galarneau 1A]

CH2Cl2 is polar because of the shape. Drawing the lewis structure doesn't show you the shape of the molecule, which is why it makes it seem like it should be non polar. However, if you draw the molecule according to its shape, it is tetrahedral, which means that the dipoles will not cancel and the molecule will be polar. It's always good to look at the shape of the molecule when doing questions like these!

[Jennifer Fuentes 2K]

Since H and Cl have different electronegativities, the C-H and C-Cl dipole moments are also different. So although the 4 dipole moments do point in the same direction, they are not equivalent and thus do not cancel, making the overall molecule polar

[Sam Forster 2J]

Hi! So Ch2Cl2 is tetrahedral meaning that the c-cl2 and the c-h bonds are not perfectly opposite of each other. A such the vectors formed by the dipole moment will not fully cancel out. In comparison to a molecule like CCl4 which is also tetrahedral, all of the bonds have the same dipole moment as such when adding up the dipole moment's vectors they will cancel out.

[Hannah Thornton 1F]

CH2Cl2 is tetrahedral and has unequal dipole moments towards the chlorine atom since it is more electronegative than hydrogen. These dipole moments don't cancel and make the molecule polar.

[Tianle Zheng]

CH2Cl2 is polar because of its VSEPR structure. This is an AX4 tetrahedral structure, and the 3D formation of it will have bond angles of 109.5 with two Cl elements producing an electronegativity charge that would not cancel each other out.

[Nithya Madhu 2L]

Hi!
It is easy to mistake that the dipoles will cancel based on the lewis structure; that is why the shape is important for this problem. The shape of CH2Cl2 is tetrahedral. This mean that the angle between the chlorine atoms is not 180 degrees, it is actually 109.5 degrees. Because of these the dipoles don't cancel and there will be a dipole moment toward the chlorine atom.
As a result CH2Cl2 is polar. I think it would be really helpful to check out 3d models of all the shapes to get a better visualization on the shape and bond angles.
Hope that helps!

[Aaron Kim 1J]

The molecular geometry of CH2Cl2 is tetrahedral, and despite looking symmetrical when drawn in a 2-dimensional Lewis structure, the molecule's actual geometry doesn't have any electron regions directly opposite of one another. Thus, none of the dipoles cancel out. (Looking up a tetrahedral shape will help).

[Sarthika Chimmula 3H]

Even though the molecule is tetrahedral and has no lone pairs, the molecule as a whole is not symmetric when you draw out its Lewis structure. Therefore, it is polar. When you figure out polarity be sure to look at what atoms are attached to the central atom and the difference in electronegativity between these atoms. (Cl is way more electronegative than hydrogen). On the other hand, if you had a molecule like CH4, the dipoles would cancel out and you would be left with a nonpolar molecule.

[805401611]

CH2Cl2 is polar due to the different in electronegativity between Chlorine and Hydrogen. Although the shape is a tetrahedral geometric shape, there is a dipole moment across the C-Cl and C-H moments when we look at the lewis structure, causing there to be dipole moments. Hope that helps!

[Ashrita Singh 2F]

Although it is a tetrahedral, H and Cl have different electronegativity values (so the molecule isn't symmetric) and as a result, there is still a dipole moment that doesn't cancel out.

[Jennifer Fuentes 2K]

Though a Chlorine atom is nonpolar, the polar molecule emerges after valence electrons of nonpolar molecules bond its properties. So, it is indeed a fact that even if there are nonpolar molecules, but the bonds do not cancel, and the geometry is showing polarity, then CH2CL2 is polar

[Wenhan Li_3d]

You should consider the different polarities between C-H bond and C-Cl bond, which lead to the polar bond unable to cancel, even though the geometry is really tricky.

[Akshat Katoch 2K]

While the shape of CH2Cl2 is a tetrahedral shape and looks symmetrical making it seem that is a nonpolar molecule. We have to look at the fact that there is a C-H and C-Cl bond and that the C-Cl bond is far more electronegative than C-H. Since Cl is more electronegative there will be a dipole movement towards Cl causing the molecule to be polar.

[Abigail Tran 14a]

The different polarities of the C-H and C-Cl bonds mean the effect of the polar bonds are not cancelled so the molecule is polar.

[805757847]

we can think of vectors when considering polarities, with vectors pointing towards the more electronegative atom. For CH4, each C-H is polar, but they are arranged in the tetrahedral way that all vectors cancel out. However, CH2Cl2 has vectors of different directions and length(C-H pointing towards C and C-Cl pointing towards Cl), so it's difficult for them to cancel out.

[Hailey Jeon]

Even though due to the fact that there are 4 ligands, therefore being a tetrahedral, the chlorines have higher electronegativity than hydrogens. This occurrence results in a uneven dipole moment that does not cancel out each other and making the central atom to have some sort of electrical charge, which makes the molecule polar.

[Arad_Badiee_2B]

Because the Hydrogen and the Chlorine atoms surrounding the carbon have different electronegativities, their dipole moments don't cancel out, hence the overall polarity of the molecule.

[Tony Chen 1F]

Remember that we draw Lewis structures in 2D for the sake of simplicity, but in real life atoms and molecules are 3D

[Amaris Cagungun 1F]

CH2Cl2 actually has a tetrahedral shape. The C-Cl bond is more electronegative than the C-H bond which causes dipole moments.

[Prithvi Raj 3E]

Even though this molecule is in a tetrahedral shape, you have to keep in mind that hydrogens and chlorine have differing electronegativities. This gives the molecule an overall dipole, as the chlorine have a stronger pull, making the molecule polar.

[Coraly De Leon]

Because this molecule is arranged in a tetrahedral shape, the dipoles do not cancel each other out, thus resulting in (+) polarity.

[505807269]

We know that CH2Cl2 has a tetrahedral structure and appears symmetrical but Cl is the most electronegative atom in the molecule, therefore there will be a greater dipole movement towards Cl. So the unequal dipole moments do not cancel, the molecule becomes polar. 

[Edriana J Altea 2G]

CH2CL2 is polar mainly because the shape can be seen as a tetrahedral which means that it is not symmetrical.

[Carla Bruebach 1C]

Because of the molecules shape (tetrahedral and not symmetrical), the dipole moments do not cancel out and so the molecule is polar.

[Lucy Farnham 1G]

I think it is because the dipoles of H and Cl are not equal so they cannot cancel out.

[605721741]

In tetrahedral structures, dipoles do not cancel.

[Aida Fraser 2I]

The Lewis structure is a little misleading here, because it suggests that CH2Cl2 is square planar, with polar bonds that can cancel out. However, make sure to keep in mind the molecular shape instead! CH2Cl2 is actually tetrahedral, which means all the bond angles are about 109.5 degrees. In this model, if only two of the bonds are polar, they won't be directly across from each other, so they wouldn't be able to cancel out. That's why CH2Cl2 would still be polar.

is it tetrahedral and not square planar because of the big electronegativity difference between Cl and H?

[Raizel Ferrer 1H]

CH2Cl2 is polar because Cl has a larger electronegativity charge than CH2 which causes a dipole-dipole force due to the difference in electronegativity. This creates permanent asymmetry with a partial positive and partial negative charges.

[JafarriNocentelli 1G]

This is because a tetrahedral shape makes it impossible to have cancelled out dipoles

[205686400]

In order to better understand the answer to this question, you should focus more on the VSPER model than the Lewis Structure. The Lewis structure is a 2D demonstration where you can't really see or understand the way the angles and ligands are positioned which could lead you to think that the dipoles cancel out when in reality they aren't directly across from each other.