Metal Solubility and Solvent

maybe you can try to dissolve in DMSO (Dimethyl Sulfoxide) is abit acidic at room temperature. so it could be a good solvent for most metal or metal complex.

Copper sulphate is quite soluble (in water)

P.S.

actually i didn't put much effort in getting the copper, i ask the school to give it to me since they were throwing it away after experiment (like replacement with zinc or something similar, then filtration)

The point of this thread is that i would like to recrystalise Copper, not any of is salt, so turning it into a sulfate is effectively a step back

No. Copper isnt soluble - as metal - in any solvent known to me. It maybe soluble in some hightemp. saltmelts though.
Copper is soluble is quite a lot of other metals when those are in a molten state

But the usual way to get copper metal is by first transforming it into one of its salts and then to precipitate it again a process called "cementation". You can guess in what form copper precipitates from the word.
If you want to get finely divided copper I suggest to form the CuCl2 salt and then to put some steel/ironwool or zincwool into the solution. Dont forget to add some NaCl!
Works like a charm. Promised, thats tried and true.

Quote:

Originally posted by Blind AngelThe point of this thread is that i would like to recrystalise Copper, not any of is salt, so turning it into a sulfate is effectively a step back

Hmm yeah, i see, actually i already knew much of this about crystal, but i wanted to be sure. My idea came from this site which as sort of "Bismuth Crystal", but as i can see it's isn't. So is there a way to do this with all metal or only some, and since I own a lot of Cu i told myselft that maybe i could try with it. Thx anyway

I disagree.

I beleive your x-ray scattering and lattice formations are actually showing Crystal-like structure that indicates closest packed arrangements that may superficially look like crystals.

But these metal "crystals" lack the ionic character of true crystals.

And that's why a real crystal shatters, and a metal "crystal" just dents.

IMHO

Hmmm...

Isn't the definition of a crystal the formation of regular molecular lattices, with defined space groups that result in the regular 'crystalline' geometric look?

Isn't it this property that allows the X-ray diffraction, in order to work out the 3D structure of the unit cell (the smallest repeating unit in the crystal)? If it wasn't crystalline and regular, X-ray diffraction wouldnt produce interpretable results! Who is to say that crystals are defined by distinct ionic regular patterns?

For instance, in protein science, proteins, which are highly heterogenous molecules, readily crystallise under the right conditions. Crystallisation is defintely not exclusively a result of ionic interactions only, instead it's the packing that matters. Often empty spaces are simply bridged by water/buffer molecules.

Yet these are univerally called crystals, and not regular non-ionic aggregates or something, with no real crystal structure. Same for benzene - it also should crystallise under the right conditions. No polarity present whatsoever.

I dont see why metals shouldnt form crystals (indeed I have seen them myself), and why they are not 'true' crystals. Even though valence electrons can move about freely, there is some order to it - at any instance in time there are electron holes and electrons, which all 'magically' are in equilibrium with each other. This is the same in ionic crystals, such as Na+ and Cl-.

Anyway - the point is - as far as i know, any molecular/atomic arrangement in a repetitive, regular manner, with defined space groups and coordinates, are crystals

[Edited on 28-4-2004 by chemoleo]

T_Pyro

I didn't claim that all crystals were formed by ionic solids, but rather that all crystals had an ionic character.

there is a charge differential between the different atoms of the molecules that make up a sugar or protein crystal this would allow for the ordered arrangement. There is none in a pure metal. All of the atoms have an equal charge.

The stronger the ionic character, the faster the crystal formation.
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But I might as well mention the fly in the ointment of my argument. Diamonds.

Diamonds are inarguably crystals, and yet, like a pure metal, they all have an equal charge.

And then there is the fact that diamonds are not stable, but at surface temperature and pressure revert to graphite.
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I am going to try and find a crystallographer to strictly define a crystal for me.

I don't beleive that the single definition of a crystal is closest packed arrangement.


I'm confused.

[Edited on 29-4-2004 by Hermes_Trismegistus]

crystals:
- a homogenous solid formed by a repeating three-dimensional pattern of atoms, ions, or molecules and having fixed distances between constituent parts, from http://natural-history.uoregon.edu/Pages/web/glossary.htm

Crystals are materials which has its molecules arranged in a specific, highly ordered internal pattern. This pattern is reflected in the crystal's external structure which typically has symmetrical planar surfaces . Many common substances, from salt to sugar, from diamonds to quartz form crystals. - from www.teachinghearts.org/dre00glossary.html

Noun 1. crystal - a solid formed by the solidification of a chemical and having a highly regular atomic structure from http://www.thefreedictionary.com/crystal

From The Structures of Crystals
A M Glazer, Clarendon Laboratory, Oxford, UK:
The crystalline state is the most stable form of all solids and is very common in nature.

Admittedly, the definition of crystals is not clear cut when it comes to permitted space groups.
Check this: http://www.siam.org/siamnews/01-98/gem.htm
The most important bit:
In the early 1980s, Dany Shechtman, a materials scientist at the Technion in Israel and the National Bureau of Standards (now the National Institute of Standards and Technology) in the United States, got some very strange diffraction patterns from an alloy of aluminum and manganese. The pictures very clearly exhibited the forbidden 5-fold symmetry. (To be precise, the symmetry was 10-fold, as if a pair of interdigitating starfish had crept into the field of view.) This couldn't be, Shechtman reasoned, so he repeated the experiment. But the starfish symmetry wouldn't go away. Shechtman then did what any sensible scientist would do: He shelved the result and started asking around.

Also, a little tour in crystallography. http://www.mse.uiuc.edu/info/mse182/t97.html
The apt reader will notice that GRAPHITE is CRYSTALLINE, despite it's homoatomic nature.
The fact that diamond is thermodynamically less stable than graphite does not mean that graphite is not crystalline.

As I already said above - the verification of whether a body is a crystal resides NOT in the closest possible packing. Noone said this.
Instead, it resides in REGULAR packing, with defined space groups.
Noone equally said that something that LOOKS like a crystal really IS a crystal. It is very likely, however, as a regular naturally formed body with defined and reproducible spacial symmetries is equally likely to have defined spacial symmetries at the molecular level, or more precisely, at the level of the unit cell (the smallest repeating unit).

And this is independent of whether it's a metal, non-metal, ionic or non ionic compound, or even antimatter.

I repeat, how do we verify this?
X-ray diffraction is the way to go. If packing is not regular (which equals amorphous), you won't get a distinct diffrication pattern, from which you can deduce the 3 D structure.
Here you got your definition.

I don't know why I bother... you seem to pointlessly resist overwhelming evidence

PS as to crystallographers, I can offer you 4 different ones to ask - shall I?

Well........that's that then.....

Quote:

Originally posted by chemoleo I don't know why I bother...

Because you luv me!!!

Quote:

Originally posted by chemoleo you seem to pointlessly resist overwhelming evidence

Not so....Look, I just rolled over.