binaryclock - 11-4-2013 at 06:18
Hello all:
I created some zinc sulfate from making a saturated copper sulfate and water solution and adding pure zinc. The zinc I used was from some
zinc-manganese(iv) oxide batteries and even though I spent about 20 minutes scrubbing the manganese(iv) oxide off the zinc of the battery, still some
traces remained.
After leaving the blue liquid and zinc overnight, the mixture has now fully reacted and I'm left with a clear solution.
Question 1: After filtering out the zinc and running it through a coffee filter, how can I further purify this solution to make the solution even
stronger?
Question 2: How can I test for the strength or purity of the mixture? Is there a way an amateur with limited equipment can do this?
I don't have any fancy glassware yet as this is still a new hobby to me and my son but I'm willing to make purchases as our knowledge advances.
Thanks!
[Edited on 11-4-2013 by binaryclock]
MrHomeScientist - 11-4-2013 at 08:21
What exactly do you mean by strength? Concentration? If that's the case, simply reducing the solution's volume by boiling the solution down a bit or
evaporating will concentrate it.
If you want high purity, a recrystallization or two will do the trick. I have a video on purification by recrystallization on my YouTube channel, and
I'm sure lots of others have done the same there. Just evaporate the solution down until it crystallizes and about 10% of the liquid remains, then
discard the liquid and rinse your crystals with ice cold distilled water. Repeated recrystallization leads to higher and higher purity, but you lose
some product each time.
When you have crystals, you can make any concentration of solution you wish. If you need to test the conc. of a solution, you can titrate a sample of
it with a soluble barium salt (usually barium chloride). Keep adding until it stops precipitating barium sulfate, then you can use stoichiometry to
calculate the zinc content.
I haven't worked with zinc sulfate, but zinc chloride is extremely hygroscopic so it's very hard to crystallize. I'm not sure if you'll run into that
problem here or not.
Sciencevamos - 2-2-2014 at 08:00
To make pure zinc sulfate just make an auqeous solution of copper sulfate an add zinc metal and fliter it off.
Here's a video:
http://www.youtube.com/watch?v=niRb5bm0mAo