The Student Room Group

dipole dipole vs vanderwaals forces difference

is the difference this:
vwf is based upon the difference in electron density within a charge cloud leading to the domino effect on its neghbouring atoms making them have a dipole moment?

permanent dipole dipole is when a differenc ein electronegativity NOT electron density results in a dipole effect
Reply 1
Original post by user1234512345
is the difference this:
vwf is based upon the difference in electron density within a charge cloud leading to the domino effect on its neghbouring atoms making them have a dipole moment?
permanent dipole dipole is when a differenc ein electronegativity NOT electron density results in a dipole effect

VdW is both idd and pdd. Most exam boards used to say that it was only idd, but they realised they were wrong about 7 years ago.
Original post by user1234512345
is the difference this:
vwf is based upon the difference in electron density within a charge cloud leading to the domino effect on its neghbouring atoms making them have a dipole moment?
permanent dipole dipole is when a differenc ein electronegativity NOT electron density results in a dipole effect

Yes, permanent dipole dipole is due to a difference in electronegativity. Anything with permanent dipole dipole will also have van der Waals/London forces.

London forces exist in all atoms with electrons (though we don’t refer atoms,only in the diatomic ones e.g the halides). They are caused by flickers of electrons spinning around the subshell in their orbital. Using a room analogy, Say there is momentarily a higher electron density on the left hand side. The left hand side will have a negative charge, and the right hand side a positive charge. These momentary flickers of charge are what causes London forces. You’re right, it is due to electron density
Reply 3
I think your correct but different exam boards use different terms for intermolecular forces, aqa call London dispersion forces Van der Waals forces, best to check your exam spec to make sure your uisng the correct terms. https://www.science-revision.co.uk/A-level_intermolecular_bonding.html
To really understand LDF I recommend this video:

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