Lab #9  Double Displacement Reactions 
Introduction:   A double displacement reaction or metathesis reaction involves the reaction of two compounds to form two new compounds. In effect, the compounds change partners with each other.  This experiment will provide you with opportunities to observe several of these double displacement reactions.
 
Purpose: To observe the formation of new substances in double displacement reactions.
 
Hazardous chemicals: silver nitrate, iron (III) chloride, sodium hydroxide
 
Equipment: 10 test tubes, 20 X 150 mm; test tube rack
 
Materials:  sodium chloride, silver nitrate, potassium iodide, iron(III) chloride, sodium hydroxide, potassium nitrate, sodium carbonate, and calcium chloride.
 
Procedure:
1. Before you get to the lab have the following information ready. You need solutions with a concentration of 0.1 M.  Calculate the number of grams of each substance required to make the correct volume of each 0.1 M solution required.
 
Compound
Molecular Formula Molecular Mass Number of 
mL's Required
Number of 
Grams Required
Sodium chloride
                10    
Silver nitrate
                10    
Potassium iodide
                  5    
Iron(III) chloride
                  5    
Sodium hydroxide                   5    
Potassium nitrate                   5    
Sodium carbonate                   5    
Calcium chloride
                  5    
2.   Label ten test tubes 1 through 10 and place them in the test tube rack.
 
3.   Weigh out the appropriate amount of each chemical and place them the correct test tube.
 
4.   Add the indicated amount of water and swirl to dissolve the crystals.
 
5.   Split the 10 mL's of silver nitrate solution evenly into test tubes #2 and #3.  Split the sodium chloride solution evenly into test tubes #1 and #7.
 Test Tube # 
Solution
    1
Sodium chloride
    2
Silver nitrate
    3
Silver nitrate
    4
Potassium iodide
    5
Iron(III) chloride
    6
 Sodium hydroxide 
    7
Sodium chloride
    8
Potassium nitrate
    9
 Sodium carbonate
    10
Calcium chloride

 
6.  Record the appearance of each reactant solution before mixing.
 
7.  Mix the contents of tubes 1 and 2 by carefully pouring the contents of one tube into the other.
 
8.  Repeat procedure 7 for the following pairs of tubes:
       3 and 4
       5 and 6
       7 and 8
       9 and 10
 
9.   Observe each of the mixtures, and record any evidence of a reaction.
 
10.  Describe the appearance and colour of any product that may be formed.
 
11. Clean the test tubes and dispose of the wastes in the waste container provided.
 
Questions:
1.  For each reaction:
     a) What evidence is there that a chemical change occurred?
     b) Write a balanced equation for the reaction.

2.  Suggest how you might be able to determine which of the products is the precipitate.

3.  Using the information from above fill in the table of solubilities.