Melting and Boiling Points

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205154661_Dis2J
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Melting and Boiling Points

Postby 205154661_Dis2J » Fri Dec 06, 2019 11:28 am

Can we assume that melting and boiling points will always be higher for hydrogen bonds than any other intermolecular force?

Connor Ho 1B
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Re: Melting and Boiling Points

Postby Connor Ho 1B » Fri Dec 06, 2019 11:49 am

Technically, yes. But the amount of forces a molecule has also plays a role, i.e. if a molecule experiences both h-bonding and dipole-dipole vs. h-bonding and LDF.

Sartaj Bal 1J
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Re: Melting and Boiling Points

Postby Sartaj Bal 1J » Fri Dec 06, 2019 11:51 am

Usually, since H bonds are a stronger IMF, their melting and boiling points will be higher. For non polar molecules, these values increase as the molecules get larger because more LDF take place.

Camille 4I
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Re: Melting and Boiling Points

Postby Camille 4I » Fri Dec 06, 2019 2:36 pm

What makes for a higher boiling point, ion-dipole interactions or hydrogen bonding?

serenabirkhoff_1K
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Re: Melting and Boiling Points

Postby serenabirkhoff_1K » Fri Dec 06, 2019 3:27 pm

Camille 4I wrote:What makes for a higher boiling point, ion-dipole interactions or hydrogen bonding?


Ion-dipole interactions are the strongest intermolecular force and therefore stronger than hydrogen bonding and therefore ion-dipole interactions have a higher boiling point.

Ayushi2011
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Re: Melting and Boiling Points

Postby Ayushi2011 » Fri Dec 06, 2019 3:34 pm

I think the hierarchy is ionic>ionic-dipole>hydrogen>dipole-dipole>london forces (in terms of strength of interaction). Higher the strength, higher the temperature it needs to break the bond so higher melting point.

ramiro_romero
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Re: Melting and Boiling Points

Postby ramiro_romero » Sat Dec 07, 2019 11:31 pm

Ionic bonds will always create the highest boiling points, hydrogen bonds are just exceptionally strong dipole-dipole interactions. Follow the general rule ionic>hydrogen bonding>dipole dipole>London dispersion

Ayushi2011
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Re: Melting and Boiling Points

Postby Ayushi2011 » Sun Dec 08, 2019 1:09 am

ionic dipole is stronger than hydrogen bonding, so needs a higher melting point in order to break the bonds.

Anna Heckler 2C
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Re: Melting and Boiling Points

Postby Anna Heckler 2C » Sun Dec 08, 2019 2:01 am

Hydrogen bonds are, in essence, the strongest type of dipole-dipole interaction. Ionic bonds will always be stronger than dipole-dipole/H bond interactions.

William Francis 2E
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Re: Melting and Boiling Points

Postby William Francis 2E » Sun Dec 08, 2019 2:46 am

Yes, I think that you can usually assume this. Hydrogen bonds only occur with Nitrogen, Oxygen, and Fluorine since these are the most electronegative atoms, so they can result in relatively strong dipoles.


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