Question

What is the difference between dispersion forces and Dipole-Dipole bonding?

Answer 1

http://chemsite.lsrhs.net/FlashMedia/html/dipoleVsLondon.html

Answer 2

dipole dipole happens between molecule that are polar so when they have a partial negative and partial positive side. LDFs occur with non polar molecules when it just so happens that the electrons on an atom are all at one end of the molecule creating a positive charge and a negative. When this happens between two molecule close to another they will be attracted to each other. Generally these are weaker and temporary forces.They call this an instantaneous dipole so since it is always in motion, these forces will eventually break.

Answer 3

In one molecule with identical atoms, electrons are evenly shared between them, so much that the distribution of charge is spread across the electron clouds of both. But in fractions of time, since shared electron constantly move and circle electron clouds, one might linger towards and atom and skew slight negative charge there while the opposite, slightly positive. Now a temporary dipole is formed, and this molecule can induce another molecule of the same type. Between them dispersion forces exist. Dipole dipole bonding on the other hand occur between polar molecules. Within them are not identical atoms like the I -I in iodine. For example take water molecules H-O-H, a special form of dipole-dipole interactions occur between them. Atoms have differences in electronegativity as oxygen is more electronegative than hydrogen so it draws electrons to its end most of the time (slightly negative) and the hydrogens give it up for most of the time (positive). These water molecules can attract to each other to create dipole-dipole bonds at oppositely charges ends.