Copper Nitrate?

[cplmac]

I was wondering if it was possible to create copper nitrate with a synthesis using nitric acid. Just bouncing it off the sounding board.

[justanotherpyro]

Depending on concentration which I'll assume you have a high molar HNO3, then you could nitrate Cu metal I believe. However, I have a feeling this is unfavorable. I know that you can synthesize it by reacting Cu metal with AgNO3 though which could be a hassle. Perhaps someone can elaborate/give a better answer.

[Sylar]

Copper nitrate can be made quite easily with 40% HNO3 and metallic copper, yielding a blue solution from which crystals can be obtained.

 

However, it's pretty hygroscopic for practical use in pyrotechnics ... perhaps in a composition with dissolved wax or vaseline?

Anhydrous copper nitrate should be (like copper sulfate) allmost white when dry, depending on purity.

 

A complex can be made with ammonia which is far less hygroscopic I believe, also commonly known as tetraamine copper nitrate, TACN.

 

EDIT: allmost forgot about the reaction between Cu and HNO3 => LOTS of deadly NOx !!

Do the reaction outside and downwind, in a fume hood or with several gas traps!

[WarezWally]

Not hard to do but as above do it down wind!

 

 

 

 

 

[edit]I removed the second link. It was more focused on how stupid people are than the reaction itself.

Edited March 26, 2008 by Mumbles

[cplmac]

Thanks everyone! I hadn't even thought of searching google for it but there's gotta be a dozen Cu+HNo3 videos on there.

[tentacles]

I wouldn't bother wasting HNO3 on making copper nitrate; get some calcium nitrate, and react it with copper sulfate. Keep in mind the stuff is nearly impossible to dry.

[InRainbows]

cpl, can I ask why you would need copper nitrate?

 

I bought copper nitrate since it can give fairly pure NO2 fumes, ideal for nitric acid.

 

But other than that, I can't see any reason you need it in pyrotechnics.

[asilentbob]

You don't use copper nitrate to make nitric acid... There is a difference between NO2 and HNO3... You would have to dissolve your NO2 in water... which really doesn't result in a very good yield. Simple distillation of HNO3 is much higher yielding, and safer so long as you watch temps.

[oskarchem]

You can't distill HNO3 over I think it is 65% (up to it's azetope(sorry don't know the exact name in english)). But unless you mean distilling H2SO4+KNO3.

[Mumbles]

It's still azeotrope in english.

 

Anyway, if you distill a mix of nitric and sulfuric you can approach pretty close to 100% concentration

[InRainbows]

Heating copper nitrate and passing the fumes over water would give pretty good yields, unless you need very high percent nitric, I mean, nitric around the azeotrope is OK for most of the synthesis I do.

[asilentbob]

No it wouldn't. Your not getting what I mean here. Dissolving a gas in a liquid generally doesn't work very well. You are going to dissolve literally like 5-15% of the NO2 the first pass through ice water, subsequent passes will dissolve even less NO2. Your looking at a total yield based on captured NO2 that is ridiculously low.

 

1lb Cu(NO3)2 = 2.42 mol

Assuming 2 mols of NO2 produced from every mol of copper(II) nitrate gives us 4.84 mols of NO2. In reality it will be lower since NO2 isn't strictly NO2 at STP, its in equilibrium with NO and other nitrogen oxides that may or may not dissolve in water forming nitric acid... Ok...

H2O + 2NO2 ---> HNO2 + HNO3

3HNO2 ----> HNO3 + 2NO + H2O

So theoretically you are getting 2.42 mol of HNO3 and 2.42 mol of HNO2, which will turn into a further .807 mol of HNO3 and 1.61 mol of NO if my calcs are correct. Thats 3.23mol of HNO3... thats ~203g of HNO3... Now since the losses are high...

 

For 5% NO2 created absorbed:

203*.05 = 10.2g HNO3

For 10%:

203*.10 = 20.3g HNO3

For 15%:

203*.15 = 30.5g HNO3

For 20%:

203*.20 = 40.6g HNO3

40.6g HNO3 =

1.51 g/ml for 100%...

40.6g * 1.51 = 61 ml of 100% HNO3...

 

So your willing to use up a full pound of copper(II) nitrate to make probably less than the dilute equivalent of 61mls of 100% nitric?

 

 

If you distilled:

H2SO4 + Cu(NO3)2 ---> 2HNO3 + CuSO4

2.42 mol of Cu(NO3)2 makes 4.84 mol of HNO3...

4.84 mol HNO3 = 302.4g HNO3

302.4g* 1.51 = 456.6 ml of 100% HNO3 for a full pound of Cu(NO3)2.

Assuming only 70% yeild would give:

456.6ml*.70 = 319.6ml of 100% HNO3 or the dilute equivalent.

 

Distilling is 5x more efficient.

(319.6ml / 61ml = 5.2)

 

Distill. NO2 is NOT your friend.

[cplmac]

cpl, can I ask why you would need copper nitrate?

I don't really know, just bouncing ideas around. I did find copper nitrate for sale, but it sounds like a somewhat useless chemical for pyro. I have read that dissolving it in water will yield nitric acid, but seeing as how I just ordered a liter of 70% nitric acid I don't really need to go through that headache. I think I was hoping for a blue formula oxidizer.

[Mumbles]

Like others have said, I think it's too hygroscopic to really be of much use in compositions. Perhaps with some sort of resin binder. I know there is something useful that can be done with it, but I am drawing a blank right now. This post will probably be edited later.

[TheSidewinder]

This thread tickled a VERY faint memory.

 

Seems to me Copper Nitrate was used in Medicine for something, maybe a crude disinfectant? Or as a "carrier" for some other ingredient in an oinment/salve?

 

Been too long.

 

M

[tentacles]

It can be used to make lead nitrate easily. Just take lead metal and put it in a copper nitrate solution. The lead will displace the copper, and the copper will precipitate out. Useful if you're trying to make a lead dioxide anode, and have a workable game plan to do so.