Chapter 9: Solutions Flashcards
Solubility rules
1) salt containing ammonium (NH4+) and alkali metal (group 1) cations are water soluable
2) all salts containing nitrate (NO3-) and acetate (CH3COO-) anions are water soluable.
3) Halides are water soluable (excep fluorides), with the exception of those formed with Ag+, Pb+, Hg2^2+
percent composition by mass
mass of solute/ mass of solution x 100%
mole fraction (X)
Xa = moles of a / total moles of all species
Molarity
M = moles of solute / liters of solution
Molality
m = moles of solute / kilograms of solution
Dilution
Mi Vi = Mf Vf
Solubility product constant
K_{sp} = [A^+]^a [B^-]^b
K_{sp} = solubility product constant
A^+ = cation in an aquious solution
B^- = anion in an aqueous solution
a, b = relative concentrations of a and b
Ion Product
IP = [A^+]^a [B^-]^b
IP < Ksp
unsaturated, solute will continue to dissolve
IP = Ksp
saturated, solution is at equilibrium
IP > Ksp
supersaturated, solution will precipitate
Raoult’s Law (vapor pressure depression)
Pa =Xa Pa’
Pa’ = vapor pressure of solvent A in its pure state
Xa = mole fraction
Pa = vapor pressure of solvent A
Boilling point elevation
ΔTb=i Kb m
i = van’t Hoff factor, correspond to the number of particles into which a compound dissociates in solution
Kb = proportionality constant charactheristic of a particular solvent
m = molality of the solution
Freezing point depression
ΔTf=i Kf m
i = van’t Hoff factor, correspond to the number of particles into which a compound dissociates in solution
Kf = proportionality constant charactheristic of a particular solvent
m = molality of the solution
Osmotic pressure
\Pi=i M R T
\Pi = osmotic pressure
i = van ‘t Hoff index
M = molarity
R = ideal gas constant
T = temperature in Kelvin
