Plunkett - 1-5-2017 at 08:19
A while back I was growing some copper crystals with electrolysis and once I was done, I put my fairly concentrated but not saturated copper sulfate
solution in a pickle jar for storage. I forgot about it and came back a few days later to find that the solution had separated into two distinct
layers. The bottom layer was dark blue while the top was nearly colorless. I shook the jar and the layers mixed back together and never separated
again. What could have caused the solution to separate like this?
For reference, the copper sulfate I was using came from Zep Root Kill and I had filtered off all of the insoluble impurities. I had about 2 liters of
the solution. The jar was sealed and kept in my garage at around 27 °C.
Amos - 1-5-2017 at 10:36
Copper being taken into or from your solution via your electrodes likely occurred on a pretty small surface area, right? Moderately concentrated
copper sulfate solutions are significantly more dense than water alone; you can even carefully pour one into water and watch it settle underneath
without mixing. But once they've been manually mixed together and the ions are equally distributed throughout the solution, there's nothing dense to
sink anymore.