How do i know if a molecule has a dipole moment?

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Julia Mazzucato 4D
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Joined: Fri Aug 30, 2019 12:17 am

How do i know if a molecule has a dipole moment?

Postby Julia Mazzucato 4D » Wed Nov 06, 2019 11:04 am

Is there a certain threshold of electronegativity difference that two atoms in a molecule must have in order to make it a polar molecule with a dipole moment?
Also are we going to be given a table with electronegativities on the midterm, or will that info be provided in the question if asked, or not at all?

Brooke Yasuda 2J
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Re: How do i know if a molecule has a dipole moment?

Postby Brooke Yasuda 2J » Wed Nov 06, 2019 11:42 am

A dipole moment is a charge separation that is caused by differences in electronegativity differences. Therefore, if the two atoms that are bonded together are the same element, they have the exact same electronegativity and will be non polar. Otherwise, if there is a difference in electronegativity, the bond will be polar and this means that there are partial positive charges and partial negative charges.

805097738
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Re: How do i know if a molecule has a dipole moment?

Postby 805097738 » Wed Nov 06, 2019 1:02 pm

Brooke Yasuda 4B wrote:A dipole moment is a charge separation that is caused by differences in electronegativity differences. Therefore, if the two atoms that are bonded together are the same element, they have the exact same electronegativity and will be non polar. Otherwise, if there is a difference in electronegativity, the bond will be polar and this means that there are partial positive charges and partial negative charges.


would this mean that all bonds [between differnt elements are dipole?

Kassidy Ford 1I
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Re: How do i know if a molecule has a dipole moment?

Postby Kassidy Ford 1I » Fri Nov 08, 2019 8:54 am

^^^ not all bonds between different elements produce a dipole because you have to take molecular shape into account. For example, in a symmetric molecule like CCl4 there would be dipoles between the C-Cl bonds, but they would all cancel each other out because of the symmetrical shape of the molecule

Nuoya Jiang
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Joined: Sat Sep 14, 2019 12:17 am

Re: How do i know if a molecule has a dipole moment?

Postby Nuoya Jiang » Fri Nov 08, 2019 10:30 am

A symmetric molecule usually does not have a dipole moment, but if it is asymmetric, check the difference in electronegativity, so you can find out its dipole moment.

Justin Quan 4I
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Re: How do i know if a molecule has a dipole moment?

Postby Justin Quan 4I » Fri Nov 08, 2019 12:24 pm

To add on, you can think of dipole moments as vectors, in which the vector points at the direction towards the more electronegative atom. If all the vectors cancels out, then the molecule does not have a dipole moment.

Timmy Nguyen Dis 1I
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Joined: Sat Aug 17, 2019 12:17 am

Re: How do i know if a molecule has a dipole moment?

Postby Timmy Nguyen Dis 1I » Fri Nov 08, 2019 12:26 pm

If a molecule is not symmetrical, it is probably going to have a dipole moment.

Amy Xiao 1I
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Joined: Sat Jul 20, 2019 12:15 am

Re: How do i know if a molecule has a dipole moment?

Postby Amy Xiao 1I » Sat Nov 09, 2019 5:39 pm

To summarize, all molecules have dipole moments unless they are between the same element and/or symmetrical?


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