General Chemistry I
d/n conduct electricity very well.
form ions in solution
be several types of electrolyte
How Compounds Dissolve
apart’ to form ions
not form ions on dissolving
form ions by subsequent reaction with water!
that leaves a significant amount of reactant when complete
of forward reaction equals rate of reverse reaction
º H+ + A-
n º indicates
a ‘reversible reaction’
(but not all) HA forms H+ + A-
not confuse with solubility!
n React or dissociate completely to form ions
n NaCl, HCl, NaOH…
n Form ions in solution, but most molecules remain
n NH3, HC2H3O2,
n No ion formation in solution
n Sugar, ethanol,…
Problems: 1 – 7 odd
Acetate - NO EXCEPTIONS
- EXCEPT Ag+, Pb2+,
Br-, I- add Hg2+ to the Cl- solubilities
- EXCEPT Ca2+, Sr2+, Ba2+,
now, insoluble means less than 0.01M
detail in Chem II
- IA, IIA, and NH4+
Phosphates - IA and NH4+
- IA, Ca2+, Sr2+, Ba2+
+ CD 6 AD + CB
has to happen on the product side!
soluble weak or nonelectrolyte
familiar form is the molecular equation
+ 2KI(aq) 6 PbI2(s)
strong electrolytes as ions
+ 2K+(aq) + 2I-(aq) 6
PbI2(s) + 2K+(aq) +
ions with same formula and charge on both sides of the chemical equation.
2I-(aq) 6 PbI2(s)
balanced molecular equation
all strong electrolytes (soluble ionic species, strong acids, and strong bases)
out spectator ions
to see if stoichiometry is still smallest whole number ratio!
Problems: 9 - 15 odd
one or more H+ in water
called ‘proton donors’
be monoprotic or polyprotic
dissociate to form H+
HBr, HI, HNO3, HClO3, HClO4, H2SO4
some H+ from molecules
equilibrium with unionized molecule
protons from acids
OH- concentration in water
hydroxides (most important)
Ba(OH)2, Sr(OH)2, and Ca(OH)2)
n M is
a Group I cation
properties to weak acids
Strong and Weak Electrolytes
written first in chemical formula
n Not a
(H+) and base (normally OH-) recombine to form water
have other bases
S2-, CO32-, …
n H+ and OH-
will have ions associated with them
‘other’ ions form a salt
= ionic compound
n HCl +
NaOH 6 H2O + NaCl
+ Acid often gives salt + water
n NH3 + HCl 6
detailed look at acids will show presence of water even here!!!!
of a gas
n 2H+ + S2-
n 2H+ + CO32- 6
H2O + CO2
and baking soda!
Problems: 17 - 31 odd
Reaction of Metals
redox observed were metals with oxygen, so metal was ‘oxidized’
discovery of ‘electrons’ a better understanding of the process was obtained
need oxygen for oxidation!
number (ON) assigned by a set of rules.
form – ON = 0
ion – ON = ionic charge
means ON = +2
– number in parenthesis is the oxidation number!
means ON = -1
– ON = -1 in all compounds
halogens usually -1
– ON usually -2
n -1 in
when bonded to nonmetals
when bonded to metals
a neutral compound, the sum of all oxidation numbers is zero.
a polyatomic ion, the sum of all oxidation numbers is equal to the charge on
the polyatomic ion.
Redox Reactions of Metals
n Much more detail in Chapter 20!
n Displacement reactions
n Single replacement reactions
n Reaction with metallic ion or H+
n A + BX 6 AX + B
n Zn + 2AgCl 6 ZnCl2
n Zn + 2HCl 6 ZnCl2+
CAN’T HAVE OXIDATION WITHOUT REDUCTION!
Predicting Displacement Reactions
to predict if reaction will occur.
4.5, pg 124
‘1/2 reactions’ for the metals
a reactant metal is listed above a product ion , the reaction will
n Predict if the following reactions will occur!
Fe + 2HCl 6 FeCl2 + H2
Cu + 2HCl 6 CuCl2 + H2
Mg + FeO 6 MgO + Fe
n Yes – Sacrificial anode
Problems: 33 - 45 odd
of solute to amount of solution or solvent.
of solute to liters of solution.
it is a ratio of moles of solute to L of solution, we have another path to get
as conc. of salt or individual ions
M Na2SO4 or 0.040 M Na+ and 0.020 M SO42-
of more solvent.
can be any unit if they are the same.
volumes are volumes of solution.
for which the concentration of the solute is known very accurately.
equivalent amounts of reactants (neither reactant is the limiting reactant, or
both reactants are the limiting reactant)
M as a conversion factor.
Problems: 47 - 73 odd
n Calculate molarity, solution volume, or moles of
solute given any two of these quantities.
n Calculate the volume of a more concentrated solution
that must be diluted to obtain a given quantity of a more dilute solution.
n Identify substances as acids, bases, or salts.
n Predict whether a substance is a nonelectrolyte, a
weak electrolyte, or a strong electrolyte from its formula.
n Predict the ions formed by electrolytes when they
dissociate or ionize.
n Identify the spectator ions and write the net ionic
equations for solution reactions starting with their molecular equations.
the products of metathesis reactions and write balanced chemical equations for
the driving force for any metathesis reaction.
solubility rules to predict whether a precipitate will form when electrolytes
n Use the activity series to predict whether a reaction
will occur when a metal is added to an aqueous solution of either a metal salt
or an acid; write the balanced chemical molecular and net ionic equations for
n Calculate the concentration or mass of solute in a
sample from titration data.