[hardy]

hi all, i`m new comer here.i need your help about gold chemicals
i`m on experiment about gold
i use HNO3+HCL to make gold change to water but i dont know how to get back my gold because my gold change to water,can someone help me?
one more,how can i sparated gold+iron+copper?what chamicals i need to part this object?
i hope someone read this question can help me to find the solution.
thanks

[tamim83]

I am not sure what you mean by "change gold into water", I guess you mean dissolve the gold in water

If I were you I would find a copy of the metal activity series.  That would definitely help you out.  Gold is not that reactive, so it would be easily dissplaced by another metal. 

[hardy]

i know not everybody believe this.but i see with my eye,my friend can do this but they dont wanna tell me what chemicals they use,so i asked you to help me please...,may be someone know the solution.
i have a jewelry store, so i want know much more about gold chemical
my friend just say they use HNO3 and HCL and another chemical thats secret!!!he dont wanna tell me.i alrady use HNO3 and HCL thats chemical is useful,my gold change in to water,but to get back my gold i dont know what CHEMICALS i must use!!!
thanks!

[Yggdrasil]

The substance your friend used is probably aqua regia.  The mixture will disolve gold, not turn it into water (for example, when you disolve salt in water, the salt crystals are not visible, but the salt is still there in the solution).

[Donaldson Tan]

1. Dilute the solution with a lot of water.

2. Prepare a rod of gold and a rod of cheap metal (maybe iron)

3. Connect both rods with a wire

4. Immerse both rods into your solution.

In this way, the displaced gold will be deposited on the gold rod, instead of being deposited on the cheap metal.

[hardy]

thank you for help me
i thing "yggdrasil" say is right.
but how can i get back my gold?
and "geadome" i will try your method.i hope it can work.
i`m really thanks to you all.

[Yggdrasil]

I think geodome's method (electroplating) is a good one.

[billnotgatez]

Which rod is made do you connect the negative source?

[Borek]

Which rod is made do you connect the negative source?

You don't use external voltage, it will be simple electrochemistry at work - iron gets dissolved, gold is electroplated. That's why you need to connect both rods.

[Donaldson Tan]

Let say the cheap metal rod used is Iron.

If you just immerse the iron rod into the gold solution, the displaced gold ions will form a coating on the unreacted iron, thus preventing furthur reaction. However, if you use the setup I had proposed, the displaced gold ions will deposit on the gold rod instead. In this way, the purity of your product (solid gold) is assured.

Fe (s) -> Fe²⁺ (aq) + 2e
The solvation of Iron is actually an oxidation process, which is described by the equation above. The electrons are then transferred from the Iron rod to the Gold rod via the wire. This makes the Gold rod negatively charged, thus attracting cations to the Gold rod.

Au⁺ (aq) + e -> Au (s)
The aqueous cation which is most susceptible to reduction is in fact the aqueous Au(I) cation in the solution. The Au(I) cation readily accepts the electron from the negatively charged gold rod and reduces to solid gold, thus depositing on the gold rod.

The electromotive force (EMF) driving the flow of electrons from the Iron rod to the Gold rod comes from the potential difference between Gold and Iron.

The overall reaction for the process is:
Fe (s) + 2Au⁺ (aq) -> Fe²⁺ (aq) + 2 Au (s)

[Borek]

Au⁺ (aq) + e -> Au (s)

Or

Au³⁺ (aq) + 3e -> Au (s)

[hardy]

i alrady used electroplate,but i cannot get back my gold.
do you have any method to me
i hope youn halp me plaese...
besides aqua regia,do you have any chemical for disolved gold?

[Donaldson Tan]

Did you dilute your solution?

The electroplating method will not work if you did not dilute the solution with a lot of water because the unreacted aqua regia will dissolve the 2 metal rods.

[billnotgatez]

After reading about the gold being precipitated out in the wiki article, I was wondering why that would not be an easier option. I would think that Sodium hydroxide would bind with the Chlorine more readily than gold. What am I missing?

[EccentricHeather]

I was wondering about this too.  I have a number of broken and tangled gold chains and other pieces of useless scrap from jewelry that I have damaged through clumsiness and/or laziness, and I thought they might be good raw materials for experimentation with aqua regia - they aren't currently useful for anything else.  I searched around and found this thread.  I also found another possibility, and I was wondering if anyone has tried this:

http://www.sas.org/E-Bulletin/2003-10-31/labNotes2/index.html

I have (or can easily get) all of the required chemicals, and I'm thinking of trying this.  If I try it (assuming I get around to it one day), I'll post about my experience.

A safety note to others who might wish to play with aqua regia:  The mixture is extremely corrosive, and it gives off toxic gases.  I would only mix aqua regia under a fume hood or outside.

Heather