vdw forces and london dispersion forcesWatch
Any help is appreciated xx
London force and VDW forces are the same thing they just have different names. They happen when the electron cloud is not even dispersed between two bonded atoms at an instant. i.e an electron cloud could be closer to one atom than another at any instant giving it a temporary delta - charge. This means the other atoms bonded to it will bd delta +. The VDW force is the attraction between D+ and D- but between different molecules.
Yes. Permanent dipole-dipoles happen between atoms that are bonded with a large difference in electronegativity. E.g H-F will have a permanent dipole as F has a stronger “electron pulling power” than H.
OCR A and AQA used to think that VdW were idid (London forces).
They now (correctly) realise that idid and pdpd are both types of VdW.
OCR A (the one I know best) will avoid using the term VdW in exams and will probably be asking questions in such as way as to make VdW NOT an allowable answer, i.e. idd or pdd would be expected but not either.