Polar vs. Non-polar
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Polar vs. Non-polar
If asked to identify if a bond is polar or non-polar, would we be given the distance between the two atoms in order to calculate the electric dipole moment??
Re: Polar vs. Non-polar
We don't need to know how to calculate a dipole moment. We only need to know what it is and determine if there is one
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Re: Polar vs. Non-polar
I believe to determine if a molecule is polar or non-polar, it is only important to know the charges on the ends of the molecule and the difference in electronegativity between bonded atoms, since ionic bonds are pretty much guaranteed to be polar.
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Re: Polar vs. Non-polar
If the molecule is not symmetric, then it is (generally) polar because the dipole moments (if any) do not cancel out. If the molecule is symmetric but the outside atoms are not the same, then it is polar because the dipole moments do not cancel out. If the molecule is symmetric and the outside atoms are the same, then it is non-polar.
Re: Polar vs. Non-polar
This isn't always true though. For example H20 has the same outer atoms and appears symmetric, but is actually very polar.
Re: Polar vs. Non-polar
In order to determine if the bond itself is polar, we look at the difference in electronegativity of the elements involved along with the characteristics of these elements (does it dissolve in water, etc.). If asked if the entire molecule is polar or nonpolar, that is when we look at if the molecule is symmetrical and if the outside atoms are the same/different.
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Re: Polar vs. Non-polar
Only diatomic molecules (ex. H2) have a truly nonpolar bond. If the two elements involved in the bond are different, there's going to be at least a little bit of electronegative difference, which results in a slightly polar covalent bond. Polarity of an entire molecule is different than when we are talking about the polarity of a single bond between two of the elements.
Re: Polar vs. Non-polar
Usually, when you're trying to determine the polarity of a molecule, you should look at the electronegativity of the atoms and then the molecular geometry.
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Re: Polar vs. Non-polar
In order to determine polarity, it's important to calculate the electronegativity of each element and find the difference. If the difference is less than 0.4, the bond is polar while if it is greater than 0.4, the bond is non-polar.
Re: Polar vs. Non-polar
Angel Ni 2K wrote:If the molecule is not symmetric, then it is (generally) polar because the dipole moments (if any) do not cancel out. If the molecule is symmetric but the outside atoms are not the same, then it is polar because the dipole moments do not cancel out. If the molecule is symmetric and the outside atoms are the same, then it is non-polar.
Thank you, this clarified a lot for me.
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Re: Polar vs. Non-polar
If the atom is not symmetrical it is generally polar.
Also looking at the difference in the electronegativities can help determine if the bond is polar or nonpolar.
Also looking at the difference in the electronegativities can help determine if the bond is polar or nonpolar.
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