Rhodium (et al),
Some questions:
1) If you have a lower concentration of formic, distillation of the excess water at 100C, followed by distillation of the azeotrope should yield 77% formic (bp107C), correct? The literature talks about vac distillation, but isn't that is only for higher concentrations? Formic acid thermal decomposition occurs at 160C, and I thought I remember a BASF document that stated that 85% formic exposed to atmosphere would only degrade a few percentages over a couple of months. This would indicate (to me) that simple distillation should be fine for 77%.
2) Assuming you wanted higher concentration (why?), does anyone have any idea of how much more water copper sulfate would draw out of the solution? I would imagine it would be around 85%, but thats just a guess.
Thanks,
fc
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