Aqueous Reactions and
Solution Stoichiometry
(rev. 08/28/10)
Objectives





SWBAT
Write molecular, complete ionic and net ionic
equations.
Distinguish between molecular, complete ionic
and net ionic equations.
Determine the solubility of double replacement
reaction products using the Solubility Rules.
Determine if a single replacement reaction
occurs by using the Activity Series.
Know the symbols
g
s
l
 aq
c
Drill
 What
is the difference between a “liquid
solution” and an “aqueous solution” ?
Which of the following would be an
electrolytic or non-electrolytic solution ?
 NO
 NaCl
 PCl3
 CO2
 MgSO4
 Can
you explain why?
Weak vs Strong Electrolytes
 Use
a single arrow to show a reaction with
a strong electrolyte.
 Use
a double arrow to show a reaction
with a weak electrolyte.
 Does
conducting electricity have anything
to do with this topic?
Are these weak or strong
electrolytes?
http://freshtomarket.com/01-02/electrolytes.jpg
Precipitation Reactions
Precipitation reactions are
reactions that result in the
formation of an insoluble
product.
Make sure to use an “s” to
designate the solid that
precipitates.
How do you determine if two
substances will create a
precipitate?
http://www.iun.edu/~cpanhd/C101webnotes/chemical%20reactions/images/agcl.jpg
Solubility Rules
 Use
the Solubility Rules for Double
Replacement Reactions.
 You
must memorize the solubility rules for
the AP exam and for a quiz in class.
 Distribute


a copy of the
Solubility Rules
Activity Series
Ionic Equations
 You
need to know the difference between
the following types of equations:
 Molecular
equations
 Complete ion equations
 Net ionic equations
 What
is a spectator ion?
How to write a “Net Ionic Equation”
 Write
a balanced molecular equation.
(see next slide for example)
 Rewrite the equation showing all strong
electrolytes that dissociate (or ionize) in
solution.
 Cancel out spectator ions.
Write a Complete Ionic Equation
and a Net Ionic Equation.
KCl (aq) + AgNO3 (aq) → AgCl (s) + KNO3 (aq)
Practice
Write Complete and Net Ionic Equations
AgNO3 (aq) + KI (aq) →
CuSO4 (aq) + Na2S (aq) →
CoCl2 (aq) + NaOH (aq) →
NiCl2 (aq) + KNO3 (aq) →
Net Ionic Equations
 Try
some more practice problems at:
 http://www.nauticus.org/chemistry/chemne
tionques.html
Activity Series

Use the Activity Series for Single Replacement
Reactions.

You can use the activity series to determine if
some reactions involving metals will occur.

An activity series is a list of metals arranged in
order of decreasing ease of oxidation.

See the textbook for the activity series diagram.
Activity Series Practice
 Try
some practice problems. Use the Ch 8
Single Replacement Reactions worksheet.
 Use
the Activity Series to determine if the
reactions occur.
Activity Series
 You
will need to memorize the activity
series for the AP exam.
 Look at the AP Reference packet. Take a
good look at the Standard Reduction
Potential chart.
Strong Acids

You need to memorize the list of strong acids
and bases.

Acids:







HCl
HBr
HI
HClO3
HClO4
HNO3
H2SO4
chloric acid
perchloric acid
nitric acid
sulfuric acid
Strong Bases
 Bases:


Group 1A metal hydroxides (LiOH, NaOH,
KOH, RbOH, CsOH)
Heavy group 2A metal hydroxides
• Ca(OH)2 , Sr(OH)2 , Ba(OH)2
What do you get when you mix an
acid and a base?
 Any
thoughts?
 A neutralization reaction
 Can
you explain how the water is
produced in a neutralization reaction?
Oxidation-Reduction Reactions
 OIL
 RIG
 See
oxidation is loss of electrons
reduction is gain of electrons
the textbook for the rules for
assigning oxidation numbers.
Dilution
MiVi = MfVf
i is the initial concentration
f is the final concentration
Molarity
moles of solute
Molarity = liters of solution
Molarity is another way to express concentration.
Molality
Molality =
moles of solute
kilograms of solvent
Molality is another way to express concentration.
Titrations

Use titrations to determine the concentration of a
solution.

The point in a titration when stoichiometrically amounts
are brought together is called the equivalence point.

You titrate an unknown solution with a standard solution.
Use an indicator to show when the equivalence point has
been reached.

The color change during a titration signals the endpoint
which is very close to the equivalence point.
Titration Calculations
 If
you are given a volume and molarity for
a substance, start the calculation with that.



Convert to moles of what you know
then use the molar ratios to convert to moles
of the unknown substance
Finally, use the volume of the unknown
substance to convert to molarity.
Titrations
 You
can use the dilution equation to solve
titration problems, as long as the molar
ratio is 1 to 1.
Problems to Try
 5,
6, 7, 9, 10, 11, 13, 16, 17, 18, 21, 26,
27, 28, 35, 37, 39, 41, 43, 46, 51, 53, 54,
56, 59, 60, 63, 65, 66, 67, 69, 71, 73, 76,
78, 81, 89, 90