Copper Ferrocyanide, Copper Hydrogen Ferrocyanide Tetrahydrate, and Sodium Copper Hydrogen Ferrocyanide

A quick comment on the source of my reagents and limitations. Feel free to skip this as it does not pertain to the topic directly. I have been given nearly free range in the lab at school with a few rules (no energetic materials at the top). I have been researching various copper salts I could prepare in my free time for fun. I have decided to begin with copper 2 nitrate trihydrate, which I have already prepared by the reaction of copper (removed from old power cables and wires) and nitric acid (pictures below show a concentrated solution of this salt and and later the solution after being boiled down and cooled to room temperature). Wanting to maintain my promise to not cause a sudden unplanned rapid disassembly of the fume hood I will not keep to my original plan to synthesize tetramine copper 2 nitrate.

According to "http://iron.atomistry.com/copper_ferrocyanide.html", the salt copper ferrocyanide (Cu2[Fe(CN)6]) may be prepared by a double displacement reaction, "by mixing solutions of copper sulphate and potassium ferrocyanide, the former salt being present in excess" The copper ferrocyanide being a brown precipitate. This is supported by the following source: http://www.public.asu.edu/~jpbirk/qual/qualanal/copper.html

Question 1) Would I be able to substitute copper nitrate for copper sulfate? Is there a reference table of the hierarchy of anion strength, or something analogous I can be provided a link to?

The first site (iron.atomistry.com) continues with the claim that an acid salt of copper ferrocyanide can be prepared by boiling the brown precipitate in an acid.

"When boiled with concentrated nitric acid, a ferroferricyanide is obtained of the composition

Cu7[Fe'Fe''(CN)22]2.30H2O.

When boiled with concentrated hydrochloric acid, the acid salt CuH2Fe(CN)6.4H2O, is obtained as a yellow, insoluble substance."

Question 2) Is there any other documentation on this?
Question 3) Why is there no liberation of hydrogen cyanide but instead such a strange reaction? I can not find any other source referring to these acid salts. (note: I am using duckduckgo as a search engine)

The website continue,

"this, when digested with solutions of the chlorides of the alkali metals, liberates hydrochloric, acid, yielding alkali cupriferrocyanides. Thus, for example, with potassium chloride: -

CuH2Fe(CN)6 + 2KCl = CuK2Fe(CN)6 + 2HCl."

I am interested in trying this out and developing a procedure these copper compounds. If anyone has any insight into this or has even prepared similar salts (copper ferrocyanides, acid salts, and so on) I would much appreciate hearing it.




[Edited on 3-3-2018 by VSEPR_VOID]

Quote: Originally posted by Boffis

I have a large number of basic chemistry books. When I am drawn into a new field I simply read-up on the field in these books. I bought nearly all of them from Amazon, though I have since downloaded many in digital form. They were mostly cheap because they are mostly pre-1960. I find that older chemistry books are more fact based and well referenced were as the more recent books tend to be more theoretically driven and less well referenced to specific compound types. While you definitely need the latter text to understand what is going on I often find that abstract theories are hard to comprehend. Sometimes when you want to prepare a compound the older works are better because they give actual details that can't easily be worked out from theory. On the other hand theory sometimes opens up possibilities that need to be followed up with experiments and that's where the fun starts. By the way, I may spend weeks reading and planning before I start mixing chemicals.