What is the difference?
Dipersion forces, Dipole-induced, Dipole-Dipole
- Thread starter jdla
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dispersion forces are london dispersion forces = van der waals interactions
basically what's happening is that even if a bond is classified as non-polar, it is not truly non-polar unless it's a C-C bond. (or any other bond where the atoms are exactly the same electronegativity)
so for example even though C-H is non polar, there is still a slight amount of electronegativity difference between C and H. this causes a transient / temporary dipole, which basically causes other transient / temporary dipoles in the molecule (and perhaps other nearby molecules. not sure about this part)
dipole-induced, i have no clue sorry 🙁
dipole-dipole is basically when two molecules have the dipoles interacting.
for example think of hydrogen bonding (a type of dipole-dipole interaction)
if you have 2 water molecules, the O on will have a partial negative charge, and the H a partial positive charge. so the H of 1 water molecule will hydrogen bond with the O of the second molecule.
this is what dipole-dipole is. when the positive dipole of 1 molecule forms a type of bond with the negative dipole of the other.
basically what's happening is that even if a bond is classified as non-polar, it is not truly non-polar unless it's a C-C bond. (or any other bond where the atoms are exactly the same electronegativity)
so for example even though C-H is non polar, there is still a slight amount of electronegativity difference between C and H. this causes a transient / temporary dipole, which basically causes other transient / temporary dipoles in the molecule (and perhaps other nearby molecules. not sure about this part)
dipole-induced, i have no clue sorry 🙁
dipole-dipole is basically when two molecules have the dipoles interacting.
for example think of hydrogen bonding (a type of dipole-dipole interaction)
if you have 2 water molecules, the O on will have a partial negative charge, and the H a partial positive charge. so the H of 1 water molecule will hydrogen bond with the O of the second molecule.
this is what dipole-dipole is. when the positive dipole of 1 molecule forms a type of bond with the negative dipole of the other.
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ok. the definitions of the three are as follow:
van der Waals interactions--intermolecular attractions and there are two forces contribute to van der Waals: Dispersion force(London force) & Dipole-dipole interactions.
Dispersion force--is the same as induced dipole-induced dipole attraction. This interaction causes transient asymmetric distribution of elections in molecule. As we rub a plastic rod with fur, it can attract a few peices of small paper. this is an example of induced dipole. Or you can think of it as follow: initially there is not dipole movement of Molecule A(it is in a neutral state), when another molecule (molecule B) comes closer to A, B induces A's elections to move close to the side near B or away to the other side further from B. This can be called induced dipole-induced dipole. it is transient; as B moves aways, A goes back to its neutral state.
Dipole-dipole interactions--stronger intermolecular forces than dispersion force or London force. It is an interaction between molecules or part of molecules with permanent net dipole. i.e HCl has a dipole moment.
Hope this help!!
van der Waals interactions--intermolecular attractions and there are two forces contribute to van der Waals: Dispersion force(London force) & Dipole-dipole interactions.
Dispersion force--is the same as induced dipole-induced dipole attraction. This interaction causes transient asymmetric distribution of elections in molecule. As we rub a plastic rod with fur, it can attract a few peices of small paper. this is an example of induced dipole. Or you can think of it as follow: initially there is not dipole movement of Molecule A(it is in a neutral state), when another molecule (molecule B) comes closer to A, B induces A's elections to move close to the side near B or away to the other side further from B. This can be called induced dipole-induced dipole. it is transient; as B moves aways, A goes back to its neutral state.
Dipole-dipole interactions--stronger intermolecular forces than dispersion force or London force. It is an interaction between molecules or part of molecules with permanent net dipole. i.e HCl has a dipole moment.
Hope this help!!
