London Dispersion forces: imfs that occur between non-polar molecules due to attractions of opposite charges. These forces result in instantaneous dipole movements.
Ion-Dipole & Dipole-Dipole: caused by attractions between positive and negative poles in a polar compound.
Hydrogen bonding: dipole forces with a polar hydrogen atom
One substance in particular has many of these forces at work! H2O has both London dispersion forces and hydrogen bonding:
Why review IMFs? To help explain the explore lab we recently completed! We added pepper on top of water in a cup, i covered my finger with soap and as I placed my finger in the water, the pepper quickly dispersed. As you can tell by the video we are entertained easily :)
The cause of this is likely to be explained by a dipole-dipole interaction from the soap! Soap is what is called a "surfactant" meaning it has the ability to lower the surfaces tension between two liquids or a liquid and a solid! As I stuck my soap covered finger in the water, it caused a rearrangement in the H20 molecules thus resulting in a movement across the water causing the pepper to outline the edge of the cup.
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