Unit 3: Intermolecular Forces and Properties Flashcards
Polar Covalent Bond
Unequal sharing of electrons
Dipole
A pair of opposite electric charges separated by some distance, represented by δ and a positive or negative charge
Intermolecular forces (IMFs)
Forces that exist between molecules in a covalently bonded substance
Dipole-Dipole Forces
Occur between polar molecules
Dipole Moments
The measurement of strength of electrical dipoles
Hydrogen Bonds
Type of dipole-dipole bond, the positively charged hydrogen end of a molecule is attracted to the negatively charged end of another molecule containing an extremely electronegative element (fluorine, oxygen, or nitrogen)
London Dispersion Forces (LDFs)
Occurs between all molecules. At a given moment, a nonpolar molecule might have more electrons on one side than on the other, giving it an instantaneous polarity
Polarizability
The tendency of a substance to form dipole moment
Vapor Pressure
When molecules hit the surface of the liquid with enough kinetic energy to escape the intermolecular forces holding them to the other molecules and transition into the gas phase (no outside energy needs to be added)
Dissociation
When an ionic substance disolves and breaks up into ions
Electrolytes
Free ions in a solution that can conduct electricity
Chromatography
The separation of a mixture by passing it in solution through a medium in which the components of the solution move at different rates
Rf Value
(Distance traveled by solute)/(Distance traveled by solvent front)
Analyte
The solution that is being separated in chromatography
Eluent
The second solution that is added in chromatography
