Chemistry Lab
Date __________________ Period __ Name ____________________________
CW double replacement lab 042706.doc
rev. 120110
Double Replacement Reactions
Introduction:
The goal of this lab is to observe double replacement reactions and evaluate the usefulness of the
“solubility rules”. In these double replacement reactions two aqueous compounds will potentially
combine to produce an insoluble product. In reality, not all combinations will produce an insoluble
product. Only when there is an insoluble product has a reaction actually occurred. Based on your
observations you will be able to determine if the solubility rules are good predictors of double
replacement reactions.
Instructions:
In this lab you will combine each compound with every other compound and look for the formation of
an insoluble product. Duplicate the table below in your lab notebook. (Record your observations in your
notebook. When you have completed the lab, you will write your results in the table below.) Place 5
drops of a solution in a rinsed test tube, and then add 5 or more drops of a second solution. After
observing the results, rinse the test tube and repeat until the chart below is complete. Write “NR” if there
is “no reaction”. Write RX if there is a reaction and describe the insoluble precipitate.
ZnCl2
AgNO3
Ba(NO3)2
Fe2(SO4)3
NaOH
Pb(C2H3O2)2
Pb(C2H3O2)2
NaOH
Fe2(SO4)3
Ba(NO3)2
Data Analysis:
1. Determine the compounds which we know from the beginning are soluble in water.
2. On notebook paper, write a balanced molecular equation for each combination where a “no reaction”
occurred. This will enable us to expand our list of compounds which are soluble in water. The
“products” of every “no reaction” are soluble in water. Write the formulas of the soluble compounds in
the boxes below.
3. For each combination where a precipitate formed there was an insoluble product. Write a balanced
molecular equation for each and use your list of known soluble compounds to predict the insoluble
product. Write the formulas of the insoluble compounds in the boxes below.
Summary – Write the results of your observations in the appropriate boxes
List the water soluble compounds grouped by anion
Acetate C2H2O2
-
Acetate C2H2O2
-
Chloride Cl-
Hydroxide OH-
Nitrate NO3-
Sulfate SO42-
List the insoluble compounds grouped by anion
Chloride Cl-
Hydroxide OH-
Nitrate NO3-
Sulfate SO42-
Chemistry Worksheet
Date __________________ Period __ Name _____________________________
CW double replacement lab 042706.doc
rev. 112910
Double Replacement Reactions
and the Solubility Rules
Compare the compounds on your lists of soluble and insoluble compounds on your summary page to the
predictions made by the solubility rules which are found in your NCDPI Reference Tables, and reprinted
below.
Part 1. Answer these questions on notebook paper.
1. What is the “indicator” that a double replacement reaction has occurred?
2. Consider the case where solutions of calcium nitrate and aluminum sulfate are combined.
a. Predict the possible products (write the correct formulas) as if a reaction occurred.
b. Using the solubility rules determine if a possible product is insoluble.
c. Write the balanced chemical equation and include state symbols.
3. How could you determine if a double replacement reaction occurs without actually doing the reaction?
4. What might account for the differences between your observations and those predictions based by the
solubility rules? For example, why do the rules predict that PbCl2 is insoluble, but you might not
observe a precipitate when Pb(C2H3O2)2 and ZnCl2 were mixed?
5. A precipitate will form when solutions of potassium hydroxide and copper (II) nitrate are mixed.
Write the balanced molecular equation for the reaction and include state symbols.
6. Write the balanced net ionic equation for the reaction described above.
7. In a similar experiment, students wanted to know if strontium sulfate is soluble or insoluble. Of
course the solubility rules predict that strontium sulfate is insoluble in water. What would be the best
choice for two chemicals that they could mix so that any precipitate that formed would be solely
attributable to strontium sulfate?
8. Using the solubility rules, write balanced molecular and net ionic equations for the reaction between
solutions of copper (II) nitrate and sodium phosphate. Be sure to include state symbols in the
molecular equation.
Part 2. Determine if a reaction occurs, write and balance the molecular equation including state symbols, then
write the net ionic equation below it. If no reaction occurs, write NR. If the equation is balanced as written, write
BAW. Answer either on this sheet or on notebook paper.
1.
Na2SO4(aq) +
LiCl(aq) →
2.
CuCl2(aq) +
AgNO3(aq) →
3.
Sr(OH)2(aq) +
4.
Fe2(SO4)3(aq)
→
AlCl3(aq) +
Zn(C2H3O2)2(aq)
→
5.
K2CO3(aq) +
NiCl3(aq) →
6.
KI(aq) +
7.
Na3PO4(aq) +
8.
HCl(aq) +
9.
H2SO4(aq) +
10.
Pb(NO3)2(aq) +
11.
CuBr2(aq) +
12.
Bi(NO3)3(aq) +
13.
AuCl3(aq) +
LiOH(aq) →
14.
FeBr2(aq) +
Al2(SO4)3(aq) →
15.
(NH4)2S (aq) +
Hg2(NO3)2(aq) →
SnCl2(aq) →
NaOH(aq) →
Ba(OH)2(aq) →
Na2S(aq) →
Fe(C2H3O2)3(aq)
K3PO4(aq) →
ZnCl2(aq) →
→