polar bonds vs polar molecules
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polar bonds vs polar molecules
how can a molecule have polar bonds with dipole moments and be a nonpolar molecule? is this when the dipoles cancel?
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Re: polar bonds vs polar molecules
What you said is completely correct. If the shape of the molecule allows the polar bonds to occur on the opposite ends, the dipoles cancel, and although the bond is polar, the molecule is nonpolar.
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Re: polar bonds vs polar molecules
Yes, it's exactly how you said it. A molecule can have polar bonds with dipole moments when the two elements have an electronegativity difference that is different enough to be called a polar bond. Essentially any 2 elements that have an electronegativity difference between 0.4 and 1.7 are considered to be covalent, specifically polar covalent. For nonpolar covalent, that is when any 2 elements have an electronegativity difference less than 0.4 so their bond will be considered nonpolar covalent. In order for a molecule to be nonpolar and have polar bonds, is when the dipoles cancel out and this is only possible when the outer (peripheral) atoms are all the same. In addition, there should be no odd number of lond pairs on the central atom because that doesn't allow the molecule to be completely symmetrical then. A good example is CCl4 because C and Cl have a different enough electronegativity difference that their bond is considered polar, but since there are four atoms of Cl with no lone pairs on C, the dipoles cancel out in all directions and we are left with a nonpolar molecule. Hope this helps!
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Re: polar bonds vs polar molecules
That is exactly correct. For example, if the shape of a structure is linear and there are two dipoles that point toward opposite ends, the dipoles will cancel and make the overall molecule nonpolar.
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Re: polar bonds vs polar molecules
That's correct. If the shape allows for the dipole moments to cancel each other out in direction and magnitude, the molecule can still be nonpolar even if the individual bonds are polar.
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Re: polar bonds vs polar molecules
Exactly! When the dipoles are equal in opposite in direction and equal in magnitude, they can cancel each other out, making these nonpolar bonds irrelevant to the overall polarity of the molecule.
Hope this helps!
Hope this helps!
Re: polar bonds vs polar molecules
Yes! All bonds are polar due to differences in electronegativities unless the bond is between two of the same atom. However, if these polar dipole moments cancel out due to a symmetrical structure, then the molecule is nonpolar. It is important to note that symmetrical refers to the molecules VSEPR structure, not its Lewis Structure.
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Re: polar bonds vs polar molecules
If a molecule is symmetric, the dipole moments in the polar bonds will cancel out, creating an overall non polar molecule.
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Re: polar bonds vs polar molecules
Yes; if the dipole moments cancel out, then the molecule will be nonpolar.
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Re: polar bonds vs polar molecules
Yes, that would mean that the charges in the molecule cancelled each other out so the molecule is non-polar
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Re: polar bonds vs polar molecules
Yes, a molecule with polar bonds becomes nonpolar when the dipoles cancel. They cancel when the molecule is completely symmetric.
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Re: polar bonds vs polar molecules
If you need an example of this you can refer to the example described in the textbook about H2O and CO2, which shows how H2O has polar bonds and is a polar molecule because of its bent shape. Whereas CO2 has polar bonds but because of its linear shape the dipoles cancel each other out so the molecule ends up being nonpolar.
Re: polar bonds vs polar molecules
Hi If a molecule is completely symmetric, then the dipole moment vectors on each molecule will cancel each other out, making the molecule nonpolar. A molecule can only be polar if the structure of that molecule is not symmetric. Hopefully this is helpful
Re: polar bonds vs polar molecules
Hi If a molecule is completely symmetric, then the dipole moment vectors on each molecule will cancel each other out, making the molecule nonpolar. A molecule can only be polar if the structure of that molecule is not symmetric. Hopefully this is helpful
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Re: polar bonds vs polar molecules
You have a polar bond when your two atoms have differing electronegativities. You have a polar molecule when these dipoles don't cancel out. Sometimes, you can have polar bonds, but they can cancel out because of their 3D geometry. I hope this helps!
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Re: polar bonds vs polar molecules
Yes ! Polarity will depend on the interaction of dipoles. IF the dipoles cancel out, the molecule will be non polar, whereas if they do not, the molecule will be polar.
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Re: polar bonds vs polar molecules
Polar bonds refer to when two different atoms are bounded that have significantly different electron affinities. This essentially means that the two elements from which those atoms are derived are far from each other on the periodic table. A polar molecule refers to when the charges on the molecule are unbalanced. For example, a molecule that has polar bonds, but those polar bonds are directly opposite from each other (as is the case for a linear structure) will be a nonpolar molecule, despite being made up of polar bonds. On the other hand, a molecule can be polar even if said molecule is made up of nonpolar bonds, as long as those nonpolar bonds aren't able to cancel each other out (as is the case for a bent molecule structure, for example).
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Re: polar bonds vs polar molecules
Just to remind it is not enough to only look at the Lewis structure you draw out when determining the overall polarity of the molecule, it is also necessary to look at the three dimensional structure to see if polar bonds cancel out as well.
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Re: polar bonds vs polar molecules
the dipoles would cancel when they are equal and opposite to each other. i think usually when there aren't lone pairs of electrons on the central molecule and when all of the outside electrons are the same or symmetrical
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Re: polar bonds vs polar molecules
Yes you are absolutely correct. Dipole moments do cancel out when the energy levels are equal to each other.
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Re: polar bonds vs polar molecules
yup! you are correct. When the electronegativity is balanced out by the dipoles canceling out, it becomes a non polar molecule. The shape can sometimes help you figure this out
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