Making copper carbonate crystals

[kc8ual]

OK, it has been a while since I have done anything with chemicals...

 

But I am bored and that is usually not a good thing in my case. But I figure playing with chemicals may be a little safer for my wife's sake then playing with electricity since 230v does make a pretty nasty pop when you do not ground something right

 

Anyway, I have been playing around and making crystals. I have done some sugars and various salts and even made some boron crystals but that ended up becoming a very big mess. I wanted to make something nice and while researching, the copper sulfate crystals caught my eye; until I saw the toxic hazard warning which is not a good thing when you have a 2 year old in the house. I then took the time looking at the other ores of copper before finding azurite and decided I wanted to make some. I have a lot of time on my hands so I really wanted to see how big I could make one.

 

I spent a while looking for information but I guess not many people attempt to grow them. That's too bad because they are very lovely. I saw a video showing how to make small ones, and I tried to recreate the process to make my own but have had very little success.

 

My attempt was via electrolysis.

 

150mL Pyrex beaker

Sodium Bicarbonate (this is what the guy used to make his in the video)

Water

Power Supply (converted PII supply 12v at 2A, 5v at 12A & 3.3v at 6A)

 

My first attempt made a pretty blue liquid but it was not a dark cobalt color and nothing formed at all even after 2 days. I made this by saturating the distilled water with baking soda (sodium bicarbonate) and made use of 2 copper electrodes at 5 volts.

 

My second attempt did not turn out very well either. This attempt I used less baking soda and used copper and aluminum electrodes at 12v. This attempt gave me more copper II oxide then it gave me crystals. I burned through 2 copper electrodes before deciding it was time to go ahead and filter out the sludge.

 

After some more research I read that making copper carbonate is much easier if I took copper sulfate and mixed it with the sodium carbonate as both the copper sulfate and sodium carbonate are water soluble whereas the copper carbonate is not.

 

So I figured great, this will be much easier, I will simply purchase some sulfuric acid (battery acid) and use copper electrodes and create a nice copper pentahydrate solution then stir in some baking soda; slowly until the reaction stops which would leave me with copper carbonate. Simply filter the solution and wait for a good seed crystal to grow and go from there. The only problem is that making the copper sulfate is taking forever.

 

Someone said to take some copper pipe and heat it up to make copper II oxide (the black stuff). Heat the pipe till it glows and drop it into a bucket of water... rinse lather repeat... until I have oxidized all of the copper i need. Then filter the water, take the black sludge, heat it up and wait for it to dry out.

 

OK, so this has turned out to be a long post, but my question is...

 

What is the easiest way to make the copper carbonate so I can grow some crystals???

 

No, I cannot readily find the chemicals ready to go. I know that they are here in the city somewhere, but cant find them as of yet. So going out and purchasing copper sulfate powder, copper carbonate powder or even copper II oxide is out of the question. Besides, I have too much time on my hands and I would love making the stuff myself. I just do not want my electric bill to go through the roof this month running an electrolysis set-up nor do I want to spend all of my money on LPG for my kitchen stove.

 

Should the sodium bicarbonate be sodium carbonate? If so, then can't I just put the distilled water in a pot, heat it up and super saturate it with the baking soda until it stops releasing CO2 and then go straight into the electrolysis? The sodium carbonate should be a 1:1 mix with the copper if I am not mistaken and if so, then at 100°C 305g of copper sulfate would dissolve in 150g of water (based on 1L of pure water weighing 1kg).

 

I think that maybe I am over thinking this one which is why I am getting stumped...

 

If you wanted to make copper carbonate crystals, with minimal materials and rudimentary tools (that's all I have. A bunch of Pyrex beakers I bought from a lab supply, some glass stirring rods, coffee filters and an old computer power supply with exposed wiring: +5v 12A, +3.3v 6A, +12v 2A, -12v 200mA), how would you go about it?

 

-Nick

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I think I may have found the problem...

 

A suspension of fine calcium hydroxide particles in water is called milk of lime. The solution is called lime water and is a medium strength base that reacts violently with acids and attacks many metals in presence of water. It turns milky if carbon dioxide is passed through, due to precipitation of calcium carbonate.

 

I remember seeing particles that I filtered out after adding the baking soda. Also as I started the electrolysis and the water heated up, it became cloudy and required additional filtering.

 

Would this be the reason the crystals are not forming? Could it be that it is reacting with the electrodes somehow and preventing the solution from being saturated properly?

 

If it does have an impact, can I remove the slack from the baking soda; oe should I go out and purchase a reputable named (Arm & Hammer) product instead?

 

-Nick

[UC]

The only way you'll be able to grow basic copper carbonate crystals is maybe in a pressurized high temperature tube with a temperature gradient and the solution saturated with carbon dioxide or bicarbonate.

 

Everyone thinks electrolysis is some sort of magic bullet. It's not.