Cliffs AP Chemistry, 3rd Edition

Experiment 14: Separation and Qualitative Analysis of Cations and Anions

Background:Qualitative analysis answers the question “What is and what is not present?”.
Although technology has replaced many of the “wet chemistry” techniques that are employed
in these lab procedures, nevertheless, the technology does not replace the understanding that
comes from knowing the reactions. The techniques employed in “wet chemistry” such as de-
canting, filtering, centrifuging, proper methods of determining pH, washing, and so on. are be-
yond the scope of this review. Furthermore, the detailed qualitative schemes for each reaction,
other than being presented in a condensed flowchart style (see Appendix D), are also beyond
the scope of a review. Instead, a “Test Tube Mystery” problem will be proposed. The solution
of this “mystery” will require you to have mastered the techniques and understanding of some
of the reactions in qualitative analysis.

Scenario:Following is a list of solutions used in this “mystery”.

0.1 M Ni(NO 3 ) 2

0.1 M SnCl 4 in 3 M HCl

0.1 M Cu(NO 3 ) 2

0.1 M Ca(NO 3 ) 2

0.1 M Al(NO 3 ) 3

0.1 M AgNO 3

3 M H 2 SO 4

6 M NH 3

6 M NaOH

6 M HCl

A student was given 10 test tubes labeled 1–10. Each tube contained a different solution from
the list above. Samples of the solutions in each tube were mixed in all possible combinations
and the results presented in the following table. From the information presented and the use of
Appendix D, logically determine the contents of each test tube, write formulas of precipitates
where necessary and support your reasoning.

Part III: AP Chemistry Laboratory Experiments