Apologia Chemistry White Powder Lab: Qualitative Analysis Scheme

We started the white powder lab, or this version, are versions of the Mystery Powder, White Powder, or Forensics Lab.  I began with a brief nomenclature review for several of the white powders: borax, glucose (corn sugar), sucrose (white sugar), cream of tartar, Plaster of Paris, Kosher salt, Epsom salts, baking soda, baking powder, and cornstarch.  Some of the powders are fine and others are more crystalline.  The first thing I did was review a few formulas and their names: sodium hydrogen carbonate or sodium bicarbonate (baking soda), magnesium sulfate (Epsom salts), calcium carbonate (plaster), and sodium biphosphate or sodium hydrogen phospate (baking powder).  We had just begun nomenclature and these were reasonable examples to try.  Next, I explained how the kids would perform the test with these reagents: universal indicator, phenol red, vinegar, water, and iodine.  The kids perform all of these tests on all of these powders.  The technique is to put a few grams into five wells of a reaction plate and then test each sample.  The key is to write detailed descriptions of any changes.  The kids perform these tests (say 10 drops of reagent on each sample of the powder) and make careful notes.  The next step is to identify these same chemicals numbered 1-10 as unknowns.  Be warned, the lab takes a long time.  Allow two-three hours.  We plan to do this lab over several class periods.  I like it because it introduces a qualitative analysis scheme, nomenclature, and lab practices.  The kids learn how important it is not to cross contaminate or pour materials back into their containers.  The kids feel like real scientists.  We had extra participants today join us!