Intermolecular Forces Flashcards
Intramolecular Force
Strong attractions between atoms in a single molecule
Intermolecular Force
Attraction between different molecules that causes them to be held together
Individual intermolecular forces are always ___ than intramolecular forces.
Weaker
IMFs and bonds depend on ___ and ___.
Charge/polarity: larger charge=stronger attraction
Distance: shorter distance=stronger attraction
Rank IMF energy from strongest to weakest
Ion-dipole
H-bond
Dipole-dipole
Dipole-induced dipole
Dispersion
The stronger the IMF, the ___ it is to pull molecules apart.
Harder
Ion-Dipole
Ion & polar molecules
Only for mixtures
Very strong intermolecular attraction
Dipole-Dipole
Two polar molecules or substances
High boilings points
For dipole-dipole, strength depends on ___.
Polarity
More polar (greater difference in electronegativity) means stronger
A larger dipole (MW) in dipole-dipole means …
Stronger attraction
Higher melting point
Higher boiling point
Hydrogen Bonds
H bonds directly to F, O, or N and the bonding atoms have relatively high partial charges
Strong intermolecular force
Overcomes effect of MW
Dipole-Induced Dipole
Polar molecule and non-polar molecule
Only for mixtures
A larger (MW) nonpolar molecule in a dipole-induced dipole leads to…
Stronger induced dipole
Stronger attraction between the pair
More soluble
Larger electron cloud (more squishy)
NO EFFECT ON BOILING/MELTING POINTS
Induced Dipole-Induced Dipole (Dispersion)
Two nonpolar molecules
Weakest IMF
Temporary attractions
Higher MW in dispersion IMF leads to …
More electrons in electron cloud
Stronger dispersion forces between them
Higher boiling/freezing points
More contact
