Sciencemadness Discussion Board

Copper in grams per liter

dale_wilson69 - 23-1-2008 at 21:40

I do not have the equipment to test the amount of copper in grams per liter. Can anyone tell me from experience approx. how much copper is in my solution in grams per liter? See image posted

Can anyone email me a pictures of what H2SO4 leached solution looks like with 40 gpl (grams per liter) of copper.

Thanks

Dale
dale_wilson69@hotmail.com

DSCN9983.JPG - 88kB

evil_lurker - 23-1-2008 at 22:20

Dump solution out of flask. Dry and weigh empty flask. Fill up flask back to the ring with solution. Weigh flask again, subract the weight of the flask from the total weight of flask+solution. This gives the total weight for 100mls of solution.

Now subtract another 100g from that weight (100ml of water weighs in at 100g or so depending on temp). The remainder should give you a rough idea of how much copper sulfate is in 100mls of solution (provided most of the H2SO4 has reacted).

To calculate grams of copper in solution, take the total molar weight copper sulfate and figure what percent per mole is copper, then multiply that by the grams of copper sulfate in solution.

Another possible way would might be to add a non-soap coated brillo type scrubbie to 100mls of solution and precipitate all the copper out, filter and weigh.

12AX7 - 23-1-2008 at 22:28

Damnit Jim, I'm a doctor, not a spectrophotometer! :P

I would guess somewhere under 0.2M. Why don't you, oh Idunno, test it? They make spectrophotometers for this.

Tim

not_important - 24-1-2008 at 00:18

Photographs are not very reliable ways of matching colours and intensities. Too much depends on the lighting used and the film + scanner or CCD in digital cameras.

Is sulfate the only anion in the solution? Are there other coloured cations?

If copper is the only strongly coloured cation, and sulfate the only anion except for traces of others, then there is a simple procedure to determine the concentration of copper.

You need two long transparent tubes. Test tubes will work if long enough or the solution is concentrated enough, plastic tubes will work because your solution does sound particularly reactive.

Make up a solution with a known concentration of CuSO4, better if it's in about the same concentration of acid. Also better if it is within a factor of 3 or 4 of the concentration of the solution you want to gage - a simple "eyeballing" of a small amount of water and CuSO4 will get you within that range.

Set up the tubes in the vertical position, with an diffused white light source under them; a piece of white paper lit with a strong light works well. Wrap paper or foil around the outsides of the tubes, leaving just the bottom and opening at top uncovered (keeping out side illumination)

Add whichever solution seems the most concentrated to one tube, filling it 1/5 to 1/4 of the way. Now add the more dilute solution to the other tube, looking down into both tubes to compare the tint and brightness of transmitted light, until they look the same. If the fuller tube is much less that 3/4 full, add more of the concentrated solution to its tube and continue adding the more dilute solution to its tube until the match again. Stop when the fuller tube is roughly 75 to 90 percent full.

Measure the depth of solution in both tubes by removing the wrappings and using a ruler. The ration of the fluid levels and the concentration of the known solution will let you calculate the unknown's concentration to 5% or better.

This works for compounds that do not change too much in amount of ionization or complex formation as you change the concentration.

chemoleo - 24-1-2008 at 18:33

Take i.e. 10 ml of that, and heat in a beaker to dryness, then roast it in a crucible of known weight under a flame until it turns all white (anhydrous CuSO4). Weigh the crucible again. There you have your concentration, i.e. 0.5 g/10 ml, or 50g/l or x mole/l.

chloric1 - 24-1-2008 at 19:05

Quote:
Originally posted by 12AX7
Damnit Jim, I'm a doctor, not a spectrophotometer! :P

Tim


Tim you so silly!:P:P:D

When you figure that one out I got some nickel nitrate solution I forgot to measure out the dissolved solids. I will post a picture of that tomorrow if anyone wants to take a guess.:D

not_important - 24-1-2008 at 22:44

Quote:

Take i.e. 10 ml of that, and heat in a beaker to dryness, then roast it in a crucible of known weight under a flame until it turns all white (anhydrous CuSO4). Weigh the crucible again. There you have your concentration, i.e. 0.5 g/10 ml, or 50g/l or x mole/l.


Works if it's only copper sulfate in the solution, and there's not too much free sulphuric acid. As it was called "H2SO4 leached solution", and the previous thread dealt with extracting metals from a complex mix of metals concentrates, I'd not bet on it being clean CuO4 until told otherwise.