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Intermolecular bonding?

I know all molecules have Van Der Waals but what molecules contain permanent dipoles? Are permanent dipoles stronger than van Der Waals?


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YES
Original post by JMaydom
YES


A very hasty response JM.

It depends very much on relative molecular mass ...
Reply 3
Original post by JMaydom
YES


Judging by your escalating use of caps and exclamation marks, I would say that finals are almost getting the better of you. Don't worry -- all done tomorrow! :h:
Original post by BJack
Judging by your escalating use of caps and exclamation marks, I would say that finals are almost getting the better of you. Don't worry -- all done tomorrow! :h:


Observational skills of the highest order ...

tried to rep, but fell foul of the blue meanies ...
Original post by charco
A very hasty response JM.

It depends very much on relative molecular mass ...


For most molecules you encounter VDW are definitely weaker. What's the typical difference.... ~ 4 orders of magnitude for most systems. Yes of course for colloids or other systems this goes out the window.

Original post by BJack
Judging by your escalating use of caps and exclamation marks, I would say that finals are almost getting the better of you. Don't worry -- all done tomorrow! :h:


STALKER!!!!!! Seriously who are you :unimpressed:
Original post by JMaydom
For most molecules you encounter VDW are definitely weaker. What's the typical difference.... ~ 4 orders of magnitude for most systems. Yes of course for colloids or other systems this goes out the window.

:


It's much less dramatic than that.

Why are iodine or sulphur solids at room temperature?

HI and H2S are polar and both gases ...

You can say that "given similar molecular masses" dipole-dipole forces are important, but you can't say that they are "per se" stronger than induced dipole-dipole interactions.
Reply 7
Original post by charco
It's much less dramatic than that.

Why are iodine or sulphur solids at room temperature?

HI and H2S are polar and both gases ...

You can say that "given similar molecular masses" dipole-dipole forces are important, but you can't say that they are "per se" stronger than induced dipole-dipole interactions.


My main problem is determining which molecules are more polar than another, I know fluorine is the most electronegative element but don't have a clue when they talk about NH3 being polar?


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Original post by UnknownError
My main problem is determining which molecules are more polar than another, I know fluorine is the most electronegative element but don't have a clue when they talk about NH3 being polar?


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In this case think of NH3 being shown in 3d as a tetrahedral, you should now see how it is a polar molecule.

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