Intermolecular forces and colligitive properties Flashcards
intermolecular bonds are weaker than
covalent
dipole-dipole forces
attractive force between 2 polar molecules
dipole-dipole forces increase as
dipole of molecules increase
hydrogen bonding
very strong dipole-dipole interaction, occurs when H is covalently bonded to a highly electronegative atom
hydrogen bonding occurs between H and _____
O, F, N
the more hydrogen bond donors and acceptors, ________
the higher the difference in properties
Ion-dipole forces
an ion interacts with a polar molecule (ex:water)
dispersion forces
caused by induced dipole when electrons from other molecules repel each other
what molecules posses dispersion forces
all of them
polarizability
ability to “move” outer electrons
polarizability trends
increases going down a group (column)
Van der Waals Forces
term for all intermollecular forces
rank intermollecular forces from weakest to strongest
dispersion, dipole-dipole, hydrogen bonding
strength of dispersion forces is related to
molecular weight (low = less)
solutions
homogeneous mixtures of 2 or more substances
in a solution, the ____ is dispersed evenly throughout the ____
solute, solvent
charge of ΔH for separation of solute particles
+ (endothermic)
charge of ΔH for the separation of solvent particles
+ (endothermic)
charge of ΔH for the new interactions between solvent and solute
- (exothermic)
charge of ΔS for formation of solution
+
saturated solution
the solvent holds as much solute as possible at that temp
unsaturated solution
less solute than can dissolve in the solvent at that temp
supersaturated solution
the solvent holds more solute than is normally possible at that temp
polar substances tend to dissolve in
polar substances
adding nonpolar chains (CH groups) increases _____
solubility in nonpolar solvent
if a molecule has an OH it is ____
polar
colligative properties depend on
only the number of solute particles
solutions of electrolytes should show ______ changes than those of nonelectrolytes
greater
how is vapor pressure effected by adding solute
higher concentrations of nonvolatile solutes make it harder to escape to the vapor phase, lowering vapor pressure
how is boiling point effected by adding solute
increase boiling point
how is freezing point affected by adding solute
lowers freezing point
ΔT is ____ to find new boiling point and ____ to find new freezing point
added, subtracted
nonelectrolytes
organic molecules
osmosis
a net movement of solvent from a high area of high solvent concentration (low solute) to low solvent concentration (high solute)
osmotic pressure
pressure required to stop osmosis
colloids
suspensions of particles larger than individual ions, but too small to be settled out by gravity
