73 replies to this topic

[EnigmaticBiker]

I'm not sure how concentrated the nitric acid was, but I don't know what to do now..Could water be added to dilute the solution before adding more BaCO3?

You could add your paste slowly to a larger amount of water and stir until dissolved.
The reaction should still work but more slowly.
Given you've got a paste I'd guess it was 60-70% conc nitric but, guessing isn't a good idea when dealing with such dangerous chemicals.
Take care.

[Bonny]

You could add your paste slowly to a larger amount of water and stir until dissolved.
The reaction should still work but more slowly.
Given you've got a paste I'd guess it was 60-70% conc nitric but, guessing isn't a good idea when dealing with such dangerous chemicals.
Take care.

I diluted the solution and added BaCO3 until reaction stopped and my litmus no longer turned pink. Regardless of how much water I added, the sludge still collected on the bottom.Could this be a mixture of nitrate and carbonate?I stirred the mixture and filtered it. I will check this weekend to see what is left in my bowl afetr some evaporation. I think I'll filter the solution again, but do you think I should heat the water first to make sure all the nitrate is dissolved before filtering?
thanks

[pyrotrev]

It's difficult to guess what might be in your sludge without knowing how much BaCO3 and acid you used. Ba(NO3)2 has a solubility of about 90g/l t room temp (and a bit over 300g/l at 100C), so if the reaction is trying to produce more than this it won't be in solution. Obviously warming it (post reaction) ought to help, you could filter hot then ccol to precipitate out the nitrate.
Stay green (but NOT 'coz you've got barium poisoning!)

[Andrew]

I diluted the solution and added BaCO3 until reaction stopped and my litmus no longer turned pink.

You should add an excess of Barium Carbonate to make sure the reaction goes to completion. Keep adding until no more dissolves, not until an indicator that is not even that accurate tells you so. The excess can be easily filtered out (because Barium Carbonate is not soluble) and then the solution can be evaporated (either drive the water off using light heating or leave in shallow dishes to evapourate)

As for sludge, you should not have any!!! Try adding an excess of water once the solution is neutral and see if that sludge goes away! If not you've done something dodge!!!

[Bonny]

You should add an excess of Barium Carbonate to make sure the reaction goes to completion. Keep adding until no more dissolves, not until an indicator that is not even that accurate tells you so. The excess can be easily filtered out (because Barium Carbonate is not soluble) and then the solution can be evaporated (either drive the water off using light heating or leave in shallow dishes to evapourate)

As for sludge, you should not have any!!! Try adding an excess of water once the solution is neutral and see if that sludge goes away! If not you've done something dodge!!!

I will add to a large amount of water, as it looks like I have not nearly enough water to dissolve all the nitrate,based on solubility of about 90g/l. Hopefully this will get rid of my white sludge. I'll be trying it this weekend...hope it works.I'll let you know how everything goes. Looks like I should have done some more research before trying this one...
Thanks pyrotrev and andrew

Edited by Bonny, 17 April 2007 - 12:45 PM.

[Bonny]

I will add to a large amount of water, as it looks like I have not nearly enough water to dissolve all the nitrate,based on solubility of about 90g/l. Hopefully this will get rid of my white sludge. I'll be trying it this weekend...hope it works.I'll let you know how everything goes. Looks like I should have done some more research before trying this one...
Thanks pyrotrev and andrew

I added more BaCO3 and the reaction seems complete as nothing happened. I still have some paste in the bottom of 2 large glass pots, but when more water was added the paste was dissloving. I filtered some of the water out of the pots into shallow containers to evaporate...hopefully yielding me some BaNO3. I will still need to add more water but am out of containers to put it in. Can this solution be evaporated in aluminum baking trays? They are cheap, but am concerned about the Al/nitrate.

[Andrew]

Can this solution be evaporated in aluminum baking trays? They are cheap, but am concerned about the Al/nitrate.

Should be fine, but I would not temp fate if it could be avoided!!! they have a thin plastic conformal coating so the Al would not under normal conditions come into contact with the water itself.

But worth saying again, it's worth trying to find something else before resorting to it. It should be perfectly fine and safe, just keep it out of the way of anything you don't what to catch fire! like your house! You know, just in case.

[Bonny]

Should be fine, but I would not temp fate if it could be avoided!!! they have a thin plastic conformal coating so the Al would not under normal conditions come into contact with the water itself.

But worth saying again, it's worth trying to find something else before resorting to it. It should be perfectly fine and safe, just keep it out of the way of anything you don't what to catch fire! like your house! You know, just in case.

After what seemed like forever, the weather here has warmed up and the humidity has dropped enough for my solution to start really evaporating. In several containers I have lots of large crystals forming, but still have some very fine white powder present, that I think is BaCO3 that went through the (coffee) filter paper. As the weather here has not been cooperating, it will take a very long time to redissolve,filter and then evaporate again...Is there a liquid that I can use to "wash" the crystals without the nitrate dissolving? Ice water maybe? I only have so many containers to use and still have a lot of the original "sludge" to water down,filter and evaporate.
Thanks

Edited by Bonny, 18 June 2007 - 01:54 PM.

[lavenatti]

Are you sure the sludge isn't barium sulfate? I've made barium nitrate several times using barium carbonate and ammonium nitrate, there is usually a pretty strong sulfur smell during heating, leading me to believe there is a significant amount of sulfate/sulfide contamination.

[rocket]

IIRC BaSO4 is an impurity in BaCO3 so the may explain the sulphur smell, I would think that CO2 would be given of by the reaction and maybe some H2S too. When you add BaCO3 to HCl you'll get a quit noticeable amount of H2S given off.

Edited by rocket, 21 June 2007 - 12:38 PM.

[Bonny]

IIRC BaSO4 is an impurity in BaCO3 so the may explain the sulphur smell, I would think that CO2 would be given of by the reaction and maybe some H2S too. When you add BaCO3 to HCl you'll get a quit noticeable amount of H2S given off.

I guess it could be BaSO4. I did the reaction using HNO3 and there was a strong sulfur odour. I guess I will have to re-dissolve and filter the crystals to remove this as well as any leftover carbonate.

[lavenatti]

Before you do all that work, why not try it in a formula? Barium compounds contaminating a green star aren't likely to change the color much. It's not like you have sodium compounds contaminating your barium nitrate.

Edited by lavenatti, 24 June 2007 - 12:45 AM.

[Bonny]

Before you do all that work, why not try it in a formula? Barium compounds contaminating a green start aren't likely to change the color much. It's not like you have sodium compounds contaminating your barium nitrate.

Good idea. I'll do a test this weekend if the solution has finished evaporating. I'll just be sure to filter the remaining solution carefully... I still have quite a lot to process and containers and space to evaporate are limited.

The only problem would be that until I purify it, I can't use it in any chlorate based compositions, due to the possibility of sulfide or sulfate contamination.

Edited by Bonny, 22 June 2007 - 05:04 PM.

[YT2095]

if you add a few drops of H2O2 into your acid BaCO3 mix, it will "kill" the H2S and stop it from stinking out the place
filter this soln and then displace it with K2CO3 to leave your nice new pure white BaCO3 as a ppt.
wash well and filter, then dry.

avoid Sodium carbonate like the plague! it only needs a few ions to totally destroy the color

I know it`s a little more expensive to use K carb, but it`s worth it in the long term

[Bonny]

if you add a few drops of H2O2 into your acid BaCO3 mix, it will "kill" the H2S and stop it from stinking out the place
filter this soln and then displace it with K2CO3 to leave your nice new pure white BaCO3 as a ppt.
wash well and filter, then dry.

avoid Sodium carbonate like the plague! it only needs a few ions to totally destroy the color

I know it`s a little more expensive to use K carb, but it`s worth it in the long term

I might try that next time, but hopefully I get enough Barium nitrate to last awhile. I tested a small amount of crystals in a lime green chlorate formula and it seemed good considering, the nitrate was not fully dry or crushed very fine...can only work on this experiment on weekends out of town. I should have quite a lot in another two weeks when I can check again, as long as it stops raining every day so my solution can evaporate.