Name_____________________________________________Block_______________
Lab ___: Double Replacement Reactions and Solubility Rules
Objective
To study various double replacement reactions, identifying precipitates and spectator
ions.
Introduction
Combining solutions of soluble ionic compounds often results in a product that
precipitates. The insoluble product can be determined by using the rules of solubility
shown on Table F of your reference tables.
Materials
Well plate, dropper bottles containing the following:
Sodium chloride, ammonium hydroxide, silver nitrate, sodium carbonate, potassium
iodide, copper sulfate, cobalt chloride, lead nitrate; chemistry reference table .
Procedure
Take a well plate and clean it completely. Place 1 drop of the following in a well:
No.
Reactants
Reactant 1 Reactant
Precipitate
Formula
2 Formula Color
1
Sodium chloride and silver nitrate
2
cobalt (II) chloride and silver nitrate
3
sodium carbonate and silver nitrate
4
potassium iodide and silver nitrate
5
6
lead (II) nitrate and ammonium
hydroxide
lead (II) nitrate and sodium chloride
7
lead (II) nitrate and potassium iodide
8
copper (II) sulfate and sodium
carbonate
copper (II) sulfate and ammonium
hydroxide
copper (II) sulfate and lead nitrate
9
10
11
12
cobalt (II) chloride and sodium
carbonate
cobalt (II) chloride and ammonium
hydroxide
Be sure not to mix any of the chemicals accidentally! To avoid this, do not put the
dropper directly on the plastic well – drop the drop a half an inch above the well plate!
Choose a combination of any two solutions that are not combined above. Describe what
happens (or doesn’t happen) below:
There is one other combination that produces a precipitate. Use your reference tables to
figure out what it is for extra credit!
Results
Writing a balanced chemical equation is not that easy. There are a number of simple steps
that you must take. The key is figuring out the formulas of the products.
1.
2.
3.
4.
5.
6.
Write the oxidation numbers of the elements over the chemical formulas of
the reactants. Do the same for the charges on the polyatomic ions – use tables
E and/or for this.
Draw the arrow to the products, and switch partners – the metal ion of one
compound goes with the non metal ion or polyatomic ion of the other
compound.
Write the charges on the product side – they do not change in double
replacement reactions!
Using the criss-cross method, determine the chemical formula of the products.
Use parenthesis when you have more than one polyatomic ion. Check with the
teacher if you’re not sure.
Balance the equations using coefficients.
Determine the identity of the precipitate using Table F. Write a downward
arrow  or (s) after the chemical formula of the precipitate.
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Sodium chloride and silver nitrate
cobalt chloride and silver nitrate
sodium carbonate and silver nitrate
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
Reactant Names
Oxidation #s
Chemical
Equation
potassium iodide and silver nitrate
lead nitrate and ammonium hydroxide
lead nitrate and sodium chloride
lead nitrate and potassium iodide
copper sulfate and sodium carbonate
copper sulfate and ammonium hydroxide
copper sulfate and lead nitrate
cobalt chloride and sodium carbonate
cobalt chloride and ammonium hydroxide
Questions
1.
What are some possible sources of error in this experiment?
2.
One student looked at a precipitate and identified the precipitate as pink. Her
lab partner insisted it was white. Sometimes it isn’t easy to tell what the color
of a precipitate is. Devise a method to find out!
3.
Why do some combinations of solutions not produce precipitates?
Summary of Results
Using Table F, identify the precipitate and give two justifications based on the table. The
first one is done for you.
No.
Precipitate
Justification #1 (soluble product)
1
Silver
Chloride
Sodium is always soluble (Group
1); Nitrate is always soluble
2
3
4
5
6
7
8
9
10
11
12
Justification #2 (insoluble
product)
Silver is insoluble with halides