Chemistry 12

So far in Chemistry 12 we have been working on Unit 3 and I have assigned questions #1-69.
The lab I will collect from you hopefully before Spring Break (so Friday).

An explanation of the results today.  It turns out that Copper (II) gets turned into Copper (I) in the presence of iodide ions so that explains why a lot of you got the bluish-green copper when burning the first precipitate.

Not sure how to explain the second precipitate though as Strontium should not have precipitated until the Carbonate/Phosphate was added.  Although Maran and Julianna did have some strontium colour in their first precipitate (which shouldn't have happened as Strontium Iodide doesn't precipitate).  So perhaps I just didn't add enough strontium to the original sample.  Which means the Q for Strontium Phosphate/Carbonate was less than the Ksp so nothing precipitated.

Anyways, write your lab report based on your observations, not based on what was supposed to happen.  Knowing what was supposed to happen might help you in your conclusion/discussion but use original observations to direct your answers.