Strong Electrolytes ( 100% ionized)
A.
Strong Acids: HCl, HBr, HI, H2SO4, HNO3, HClO4, HClO3
B.
Strong Bases: Hydroxides of group IA and II A, Except Be and Mg
C.
Soluble Salts ( ionic compounds: metal/nonmetal)
Always Soluble if these are in a compound
Except with
NO3-, Group IA, NH4+, CH3COO-, ClO4-, ClO3-
No Exceptions
Cl- Br-, I-
Pb, Ag, Hg22+
SO42-
Ag, Pb, Hg22+
Ca, Sr, Ba
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Concentration Measurements
Molarity = M =
molality = m =
moles of solute
volume of solution in L
moles of solute
mass of solvent in kg
Mole
= X = moles of substance S
Fraction
total moles in solution
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Colligative properties
van’t Hoff factor = i
i = number of ions one unit of substance
will dissociate into in solution
 CaCl2 dissociates into Ca2+, Cl- and Cl-, so i= 3.
Boiling Point Elevation
ΔT = ikbm
ΔT = increase in solution boiling point
kb = boiling point elevation constant for the solvent
m = molality
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Freezing Point Depression
ΔT = ikfm
ΔT = decrease in solution freezing point
kf = freezing point depression constant for the solvent
m = molality
Vapor Pressure Lowering
P = XPº
P = vapor pressure of the solution
X = mole fraction of the solvent
Pº = vapor pressure of the pure solvent
Add solute: Solution’s vapor pressure goes down.
Lower vapor pressure = Raise boiling point
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Solubility Product
For the reaction:
AaBb(s)
a Ab+(aq) + b Ba-(aq)
The solubility expression is:
Ksp = [Ab+]a[Ba-]b
Example: The solubility of strontium fluoride in water is 1 x 10-3
M at room temp. What is the value of its solubility product?
[Sr2+] = 1 x 10-3 M and [F-] = 2 x 10-3 M
SrF2 Sr2+ + 2F- so Ksp = [Sr2+][F-]2
Ksp = [1 x 10-3 M][2 x 10-3 M]2 = 4 x 10-9
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Intermolecular forces:
Generalizing properties
 Low boiling point = particles are more likely to
leave liquid solution
 Weaker IM forces = lower boiling point
 Lower boiling point = more vapor = higher vapor
pressure
 High boiling point = slow evaporation
 If IM forces are the same, look at formula weight.
Heavier molecules have higher boiling points.
 Strength of IM forces:
Hydrogen bond>dipole-dipole>London dispersion
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Intermolecular Forces
(Chart from Chemistry: The Central Science by Brown-LeMay et al.)
Interacting molecules
or ions
Polar molecules?
No
Ions involved?
Yes
Are polar molecules
and ions both present?
Yes
No
Are H atoms bonded to
N,O or F atoms?
No
London Forces
only
Ex. Ar(l), I2(s)
Dipole-Dipole
Ex. H2S
Yes
No
Yes
Hydrogen
Bonding
Ex. NH3, H2O
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Ion-dipole
Forces
Ex. KBr in H2O
Ionic
bonding
Ex. NaCl
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