After Exam 3 Flashcards
if you’re making a buffer with a W/S species, the ___ will always be in the greater amount
weak species
if you’re making a buffer with a CA/CB and the pKa of the acid is > than the pH you want…
the acid will be greater in amount
if you’re making a buffer with a CA/CB and the pKa of the acid is < than the pH you want…
the base will be in greater amount
the sign of G will always be the same as…
the sign of H
at the switch temp, what changes?
the sign of delta G (either spontaneous –> not spontaneous or vise-versa)
spontaneity will only switch temps if…
ΔH and ΔS have the same sign
if ΔH = (+) and ΔS = (+)…
there is a switch temp at T = ΔH/ΔS
if ΔH = (-) and ΔS = (-)…
there is a switch temp at T = ΔH/ΔS
if ΔG > 0…
K < 1, ΔS < 0, not spontaneous
if ΔG < 0…
K > 1 (Kforward > Kbackwards), ΔS > 0, spontaneous
if ΔH = (-), the reaction is…
exothermic (releases energy)
if ΔH = (+), the reaction is…
endothermic (absorbs energy)
order of strength of IMF bonds
London < dipole < H-bond
E = (-) Voltage =
NOT spontaneous
E = (+) Voltage =
spontaneous
A + B –> C + D = __/ __ || __/__
A / C || B / D
loss of electrons =
LEO
- oxidation
- reducing agent
reducing agent is a ___
product
gain of electrons =
GER
- reduction
- oxidizing agent
oxidizing agent is a ___
reactant
Reduction Table: if the slope from the reducing agent –> oxidizing agent is (-)…
NOT spontaneous
Reduction Table: if the slope from the reducing agent –> oxidizing agent is (+)…
spontaneous!
voltaic (galvanic) cell =
(E) Voltage = (+) = spontaneous!
electrolytic cell =
(E) Voltage = (-) = NOT spontaneous
breaking bonds…
requires energy = endothermic
exothermic =
release heat/energy = ΔH = (-)
making bonds…
releases energy = exothermic
endothermic =
requires heat/energy = ΔH = (+)
molality
mol / kg
colligative properties
depends on concentration ONLY
- generally: [solute]*(constant)
vapor pressure
VPL = molality solute
osmotic pressure
pressure(∏) = molality(T)
boiling point elevation
BPE - ΔTb = Kb * [molality]
increase (largest) in molality causes a…
↑ in boiling point and a ↓ in freezing point
freezing point depression
FPD - ΔTf = Kf * [molality]
calculating molality for colligative properties you…
(number of ions in solution)*(original molality)
the lowest freezing point?
largest molality
the highest boiling point?
largest molality
in order for a substance to have colligative properties, it must be..
a SOLUTION, not a pure substance (ie: NOT water or methanol)
4 colligative properties
vapor pressure, osmotic pressure, boiling point (elevation), freezing point (depression)
