1. Chemistry XXI Lab Session 10 How can we use chemical reactions to identify substances? (Two-Week Experiment)

2. Chemistry XXI Your Challenge Imagine that you work for a mining company that is about to buy a new mine in Southern Arizona. You have been asked to identify the metals present in samples of the ore extracted from the mine. What different metals are present in the ore?

3. Chemistry XXI Your group will be provided with a ore sample from the Rosemont Ranch area of the Coronado National Forrest (pictured to the right). You assignment is to determine what metals are present in the ore. The Sample

4. Chemistry XXI Your Analysis Scheme Discuss with your group your proposed analysis scheme. Make sure every separation and identification steps are sound and clear. The scheme needs to be tested. The ore needs to be put into solution. A method for re-dissolving the precipitates needs to be identified. Ba 2+, Al 3+, Ni 2+, Cu 2+ C 2 O 4 2- Ni 2+, Al 3+ SolutionPrecipitate Ba 2+, Cu 2+ Separate? Re-dissolve 1 M HNO 3

5. Chemistry XXI Ba 2+ Ca 2+ Co 2+ Cu 2+ Fe +3 Ni 2+ Co 2+, Ba 2+, Cu 2+ SolutionPPT C 2 O 4 2- PPT solution SO 4 2- PPT Cinchonine redissolve HNO 3 vBa 2+ metallic particles v Fe 3+ solution Co 2+ H2H2 Gas DMG pink PPT Ni 2+ excess 6M HCl (4x volume of original solution) blue or green solution confirms Co 2+ Cu 2+ Al 3+, Cu 2+ PPT OH - Co 2+ Al 3+, Fe 3+, Ni 2+ OH - Fe 3+, Ni 2+ solution Al 3+ PO 4 3- Al 3+ Or Cinchonine

6. Chemistry XXI Apply your analysis scheme to a mixture of known cations. Make the necessary modifications to separate and identify the metal cations in the mixture. Skill Building Tests You have 60 minutes Available resources:  Anion and test solutions.  Cation solutions prepared by your fellow students.  A mixed solution of all cations prepared by the preproom.  1 M HNO 3  Test tubes and other glassware.

7. Chemistry XXI Results and Reflections Share with your classmates what worked and what didn’t work in your proposed analysis scheme. Modify your analysis scheme based on all of the information and data that you have gathered.

8. Chemistry XXI Ore Analysis Discuss how do you propose to analyze the ore. Develop a plan that addresses the following points:  How to dissolve the minerals in the ore;  How to separate undesired materials;  How to separate and identify the different metal cations in the ore.

9. Chemistry XXI Your Real Challenge Analyze the ore sample. Available resources:  Anion and test solutions;  Cation solutions prepared by your fellow students;  1 M HNO 3 ;  An ore sample.  Test tubes and other glassware. You have 90 minutes

10. Chemistry XXI Claims and Evidence Based on the results of your experiments, present your major claims and the evidence that you have to support the answer to the challenge.  Are their claims clear?  Is the evidence reliable?  Is the evidence appropriate to support the claims?  How do you explain the results?

11. Chemistry XXI  What did you learn from doing your experiment?  How would you improve what you did?  How have your ideas changed as a result of this lab?  What do you not completely understand?  What new questions do you have? Final Reflections

12. Chemistry XXI  Beginning questions (2 p): What questions guided your explorations?  Safety Considerations (2 p): What did you do to stay safe in the lab?  Procedures and Tests (2 p): What experiments did you do to answer your questions?  Data, calculations, and representations (6 p): What observations did you make? What data did you collect? What calculations and representations helped you make sense of the data? Your Report

13. Chemistry XXI  Claims (2 p): What can you claim to answer your questions?  Evidence and Analysis (6 p): How did you interpret your results to support your claims?  Reflections and additional questions (10 p): What did you learn? What do you not completely understand? How have your ideas changed as a result of this lab? What new questions do you have? How would you improve what you did? Your Report

14. Chemistry XXI Next Week Next week we will be testing a new experiment in all of the Chemistry XXI labs. Necessary information will be posted in D2L. Remember to complete the post-lab quiz for this two-week experiment and complete you lab report.