Drill


What type of chemical reaction uses the
activity series?
What is the activity series used for?
Objective

The student will be able to:

Observe, identify, and write balanced equations
for precipitation reactions.
SAT/HSA Enrichment

a.
b.
c.
d.
Food will stay fresh longer when enzyme activity
is slowed. Which of the following conditions
would most likely slow enzyme activity?
Reducing pH from 8 to 7 by adding a weak acid
Increasing pH from 5 to 6 by adding a weak
base
Reducing temperature from 30C to 20C by
refrigeration
Increasing temperature from 30C to 40C by
heating
Reactions in
Aqueous Solution
How do elements react in water?
Reactions in Aqueous Solution
•
Structures in limestone caverns are
formed when carbon dioxide converts
calcium hydrogen carbonate into
calcium carbonate. The calcium
carbonate precipitates and forms
dramatic stalactites and stalagmites.
You will learn to predict the formation
of precipitates and write equations to
describe the reactions that produce
them.
Net Ionic Equations

A complete ionic equation is an equation
that shows dissolved ionic compounds
as dissociated free ions.
Net Ionic Equations


An ion that appears on both sides of an
equation and is not directly involved in
the reaction is called a spectator ion.
The net ionic equation is an equation for
a reaction in solution that shows only
those particles that are directly involved
in the chemical change.
Net Ionic Equations

A net ionic equation shows only those
particles involved in the reaction and is
balanced with respect to both mass and
charge.
Net Ionic Equations

Sodium ions and nitrate ions are not
changed during the chemical reaction of
silver nitrate and sodium chloride so the
net ionic equation is
Predicting the Formation of a
Precipitate

You can predict the formation of a
precipitate by using the general rules
for solubility of ionic compounds.
Predicting the Formation of a
Precipitate
Predicting the Formation of a
Precipitate

Will a precipitate form when a sodium
carbonate solution is mixed with a barium
nitrate solution?
Predicting the Formation of a
Precipitate

Sodium nitrate is soluble but barium
carbonate is insoluble. The net ionic
equation is
Section Quiz
1. Identify the correct net ionic equation for the
following reaction and the spectator ion, if there is
one.

FeO(s) + 2HClO4(aq)  H2O(l) + Fe(ClO4)2(aq)
a.
b.
c.
d.
FeO(s) + 2H+(aq) + 2ClO4-(aq)  H2O(l) + Fe2+(aq)
+ 2ClO4-(aq); no spectator ion
FeO(s) + 2H+(aq) + 2ClO4-(aq)  H2O(l) + Fe2+(aq)
+ 2ClO4-(aq); ClO4- is a spectator ion
FeO(s) + 2H+(aq)  H2O(l) + Fe2+(aq); ClO4FeO(s) + 2HClO4(aq)  H2O(l) + Fe(ClO4)2(aq); no
spectator ion
Section Quiz
2. Which one of the following products of doublereplacement reactions would NOT form a
precipitate?
a.
b.
c.
d.
AgCl
PbSO4
Mg(OH)2
Mo(NO3)2
Section Quiz
3. Which reaction will NOT produce a precipitate
from aqueous solution?
a.
b.
c.
d.
Hg2(NO3)2 + KCl
FeSO4 + Ba(OH)2
Pb(NO3)2 + Na2CO3
NaBr + Al2(SO4)2
Small-Scale Lab

Precipitation Reactions: Formation of
Solids

Purpose

Students observe, identify, and write balanced
equations for precipitation reactions.
Summary
1.
2.
3.
4.
5.
Did we accomplish the objective? Explain.
What is a net ionic equation?
What type of reactions did you work with
today?
How can you predict the formation of a
precipitate in a double-replacement reaction?
What is a precipitate?
Homework

Net Ionic Equation worksheet

Read Identification of Anions and Cations in
Solutions Lab