I am making zinc sulfate to use in electroplating and went about it two different methods because I had the material for both laying around and didn't want to buy some. First method was zinc in copper sulfate, and the second was zinc in sulfuric acid.
However, during recrystalization I got 2 very different results. I am reasonably certain that the zinc in sulfuric acid resulted in zinc sulfate. It looks right, and the solubility is in the right range. However, the other reaction has resulted in beautiful, massive crystals that look nothing like zinc sulfate.
As a side note, the second solution has a pale blue tinge to it after boiling it down to 1/3 the original volume.
This leads me think that there is copper still in there. I ran the reaction for 3 days until I could see no more copper building up on the zinc piece, and the solution was clear.
Based on the solubility of copper sulfate and that the crystals are clear, any idea as to what it could be? I will post pictures when I get back to my computer.