AP Lab #16 - Mystery of the Thirteen Solutions
One of the most important skills in chemistry is identification of unknowns.
Throughout your years of chemistry, you have learned several techniques to identify
solutions: pH tests, solubility, flame tests, color, odor, precipitation reaction, formation of
gases… just to name a few. In this lab you will identify 13 unknown solutions using any
of the techniques you have learned for identification. However, you are limited to the
equipment and chemicals provided by your instructor only. You may use the internet and
textbooks to look up information such as flame test colors and solubility of salts
precipitates. You are required two perform no fewer than TWO tests to identify each
unknown. Though a single test may not be conclusive, both tests should confirm your
unknown. Some tests may be simple tests such as color identification of a transition
metal, or odor of a solution. However, you will be required to do a minimum of FIVE
reactions to confirm your unknowns. Good Luck!
Here is a list of your unknowns:
CuSO4NH3LiNO3KNO3NaCl
H2SO4Ba(NO3)2NaOH Fe(NO3)3
KHCO3NiCl2KMnO4NaHSO3
Science Practices: [1.B, 4.A, 4.C, 4.D, 5.E, 6.A, 6.B, 6.C ]
Objective
How can we determine the identity of a group of unknown solutions using
physical and chemical properties?
Safety
Always wear safety goggles when working in the lab.
Tie back loose hair when working with a flame.
Wash hands before leaving the lab.
Materials
Phenolphthalein, pH paper, Burner, striker, wooden splint, test tubes, pipettes,
test tube rack, 13 mystery solutions
Procedure
Develop your own procedure to test and identify the unknown solutions.
Observations
68
