Solutions Flashcards
dipole:
a polar bond
dipole moment
the arrow thing represents the polarity of the dipole (points toward the partially positive side)
net dipole
the sum of bond dipoles in three dimensions
intermolecular
between 2 different molecules (IMF is between molecules of the same compound)
intramolecular
within a molecule (ie bonds)
intermolecular force
aka IMF; the attractive force between 2 molecules; significantly weaker than covalent bonds
london dispersion force
when molecules move/collide, there can be momentary shifts in their e-clouds, which is when the molecules can have a dipole that can experience dipole-dipole (only in the moment of collision)
- larger molecules have ↑ LDF (a large e-cloud can shift more b/ more “polarizable”)
- larger surface areas are also more polarizable (so connect to straight C chains that experience more LDF than branched C shapes)
- all molecules can experience LDF
dipole-dipole
exists between 2 polar molecules: when 1 molecule’s partially positive side is attracted to another molecule’s partially negative side
hydrogen bonding
when an e-deficient H makes a partial bond with a lone pair on a different molecule –> like a special case of dipole-dipole
- the H must be directly bonded to a F, O, or N (the most e-neg and smallest elements)
- there must be a lone pair in addition to either an F, O, or N
- a bond must be all the e- the H has, so the H must be extremely partially positive
alcohols
all alcohols can h-bond because they all have a C bonded to an O (with 2 lone pairs) bonded to an H
solution
a homogenous mixture with 2+ substances
solute
what’s being dissolved
solvent
what’s doing the dissolving
solubility
a solute’s max. concentration that can be dissolved in a given solute in certain conditions
solvation/dissolution
the process by which solutes dissolve into the solvent
miscible
when 2 liquids can turn into a homogeneous mixture
immiscible
when 2 liquids can’t turn into a homogeneous mixture
dilute solutions
relatively low solute per unit of solvent
concentrated solutions
relatively high solute per unit of solvent
saturated solutions
maximum amount of solute dissolved
unsaturated solutions
less than the maximum amount of solute dissolved
supersaturated solutions
more than the maximum amount of solute dissolved (prone to crystal formation)
describe the solvation process
- solute particles separate from each other (IMF broken, requires energy)
- solvent particles separate from each other (IMF broken, requires energy)
- solvent and solute mix and interact (new IMF between the solute and solvent molecules; releases E)
h-bond acceptor
molecules that can’t h-bond but have a lone pair on F, O, or N, which can accept e-deficient H to form an h-bond
- H-bond acceptors can mix with h-bonding solvents TO A POINT
- solubility is lower the more nonpolars (C) in an acceptor
ionic compound solubility
aka ion-dipole force
polar molecules can surround ions, stabilizing ionic charge and allowing for solvation: only H2O is small and polar enough to do this as a solvent, and most ionic compounds dissolve in it
biphasic liquid mixture
immiscible liquids form distinct layers, with the denser liquid on the bottom
hydrophilic
hydrophobic
amphiphilic
doesn’t mix with water
mixes with water
a molecule with hydrophobic and hydrophilic regions
1 mole
6.023 x 10^23
aka Avagadro’s Number
concentration
the measure of the amount of solute in a solution
percent by mass
better for liquids
%mass = [(mass solute)/(mass solution)] x 100
percent by volume
better for solids
%vol. = [(volume solute/(volume solution)] x 100
mole fraction
X = n (subscript) solute / n (subscript) total)
Usually ends up needing mole mass to set up with volume → like “volume x 1 mole/mm”, then plugging in for the solute; doesn’t end with a unit
molarity
aka M
M = n/v (moles over L)
The moles solute per liter (L) of solution; most common and important for chemists
dilution
a solution with a fixed amount of solute can’t be concentrated in a controlled manner, but can be diluted to have a solution with a desired lesser Molarity
