The 7-Solution Lab
PRELAB: Due before coming to class to perform the lab
1. Using the Solubility rules predict which combinations will produce a precipitate.
2. Write balanced net ionic equations for each of the potential reactions in this lab.
When you begin the lab, you will be given the 7 known solutions that you will use to create chemical reactions
noting how each reacts and confirming your predictions about precipitate formation.
1. You will use the net ionic equations for each known reaction to confirm your predictions.
2. Next, you will be given a set the same solutions but you will not know which one is which. By mixing small
portions of each solution you are to determine the identity of each unknown solution. No other reagents,
indicators or instruments are to be used.
Materials:
1-micro scale well plate or Glass Plate
The Seven Solutions are:
Solution 1- AgNO3
Solution 5 – NaOH
Solution 2- (NH4)2CO3
Solution 6 – Na3PO4
Solution 3- NaCl
Solution 4 – Pb(NO3)2
Solution 7 – Na2SO4
Procedure:
1. In your clean micro scale well plate (or glass plate) add 2 drops of solution #1 to the first seven cells in the
top row.
2. Next add 2 drops of solution #2 to the first seven cells of the second row.
3. Continue in like manner for each of the rest of the solutions. CAUTION: Avoid cross contamination of the
samples at all cost!
4. Now test each known solution with each of the other solutions. Begin by adding 2 drops of solution #1 to
each cell in the first column of your well plate. Record your observation in each corresponding box on the
table that you constructed. Pay particular attention to the formation of precipitates or other distinctive
changes.
5. Continue testing by adding 2 drops of solution #2 to each of the cells in the second column of the well plate.
Again, record you observations.
6. Test in like manner until all solution combinations have been tested.
7. Using the other data table repeat the testing process as before using the known solutions against the
unknowns.
8. Finally compare the two data tables to determine the unknown solutions.
9. When you have determined the identity of the solutions, fill out a 7-soultion Lab Prediction Page and turn
into your instructor.
Data Tables: Record whether a precipitate (ppt) is formed and record any color that may help when
determining the unknowns.
AgNO3
AgNO3
(NH4)2CO3
NaCl
Pb(NO3)2
NaOH
Na3PO4
Na2SO4
(NH4)2CO3
NaCl
Pb(NO3)2
NaOH
Na3PO4
Na2SO4
Data Tables for testing unknowns against the knowns.
A
AgNO3
(NH4)2CO3
NaCl
Pb(NO3)2
NaOH
Na3PO4
Na2SO4
B
C
D
E
F
G
Seven Solution Problem Prediction Page
Name_________________________
Letter
Rationale
Include at least 1 net ionic equation
A
B
C
D
E
F
G
Period_________
Formula