Question about long term storage of Nitric Acid vs Muriatic

[TommyP]

I am new to this forum so excuse me if I do anything wrong or out of the ordinary. A quick push in the right direction and I should be good to go. Also, hello to everyone and I hope in time I will be able to be an asset to this community - time will tell.<br><br> Anyways, I have been getting a lab set up and collecting chemicals for the last two months and I am almost complete. Just a few more chemicals that are hard to get and I should be well stocked. Two of the last acids I needed were muriatic and nitric. My friends father use to work at a metal plating factory and his son has taken over his home as he was moved to an elderly community. He has found numerous chemicals in his fathers basement and he was more than happy to give them to me than to pay a disposal fee. To my surprise he also had fuming white nitric acid and muriatic acid. The only problem was the two 5 gallon jugs of each were stored outside under his pool deck. We live in Canada with temperature fluctuations from minus 30 to over 30 degree's C. Also, they were stored this way for the past 23 years!<br><br> I took samples of both home to test. So far I tested the muriatic and it is as strong as it has always been. The nitric I am testing tomorrow.<br><br> My question is, what are the chances of the nitric being as potent as the muriatic? Also, is it a norm for muriatic to last under these conditions without loosing potency? Both are five gallon drums and full to the rim and capped well. May be this contributed to the preservation? I have far less hopes for the nitric as I think it is not as robust a chemical when time and temperature are not on its side. One good thing is I have found nitric acid very easy to distill, so it could possibly be saved?. I think it would be worth the extra effort as it's almost impossible to get around here and have not found a place that will ship to me. Thank you very much in advance and I look forward to hearing your response. I will get back to you all and let you know how the nitric acid test goes - that is if anyone is interested lol.<br><br>TommyP

[WSM]

Nice Find. Let us know how the testing goes.

 

WSM

[Mumbles]

The muriatic acid (hydrochloric acid) should be fine. It will be a clear to slightly yellow/green color. The actual compound in muriatic acid is hydrogen chloride, which is actually a gas. It might not be quite as strong as it once was, but should be pretty good still. It seems to store reasonably well.

 

Nitric acid might still be okay. The biggest indicator is the color. Clear should mean minimal degradation. More than likely it will have some shade of yellow or orange to it. This is common, and is particularly accelerated by light. A little color will be fine, a lot of color might require a little purification. The color is from nitrogen oxide decomposition products. Distillation should yield good acid, but there are some tricks to decolorize it if you need to. There are a few sensitive reactions that may need very clean nitric acid.

 

I'm not sure what sort of chemistry background you have, but a titration will probably be required to get some idea of current concentration. You might also try to measure the density. The biggest form of "degradation" you're likely to encounter with these is just dilution from label concentration over time if they were stored properly.

 

It sounds like you got quite the find.

[TommyP]

Thanks for the response and sorry to get back to this thread so late. I did examine the nitric and it is as clear as water, which I am quite surprised by the years and temperature changes. One thing I did notice is it doesn't seem to be white fuming acid like it is labelled as when air is blown in or over it, there is only a slight mist or fuming. I guess it could be due to the cold temperature it was outside when I tried it? I tried dissolving a copper penny in it and it reacted slowly at first, then I put a couple drops of water in and it heated up instantly and dissolved the penny in about 2 minutes. So I guess I made copper nitrate as my first experiment with it as the solution is dark blue. I continued dissolving pennies until the reaction came to a hault. I dissolved three in a very small amount of acid. If I heat this will I get crystals of copper nitrate that will stay in crystal form, or is copper nitrate highly hydroscopic? Or, should I add ammonia in small drops in a fume hood to create copper hydroxide as I need both? Which is less hydroscopic and easier to store would be the one I want now, so which is easier to store? Sorry for all the questions again and thanks in advance. I am very excited to go through all the chem's as I picked them all up late last night. Edited June 29, 2013 by TommyP

[taiwanluthiers]

I think white fuming reacts slowly with copper because the reaction was so fast that it passivates the copper. When you dilute it the passivation no longer happens and the reaction proceeds quickly. Be careful with this reaction (I hope you did this under a fume hood) because nitrogen dioxide is very bad for you, and the reaction produces a lot of it.

[Mumbles]

It sounds like it's still pretty concentrated. Maybe not fuming, but probably 90+% Concentrated acid, as Taiwanluthier alluded to, reacts differently than more dilute acid. It ionizes differently.

[WSM]

Thanks for the response and sorry to get back to this thread so late. I did examine the nitric and it is as clear as water, which I am quite surprised by the years and temperature changes. One thing I did notice is it doesn't seem to be white fuming acid like it is labelled as when air is blown in or over it, there is only a slight mist or fuming. I guess it could be due to the cold temperature it was outside when I tried it? I tried dissolving a copper penny in it and it reacted slowly at first, then I put a couple drops of water in and it heated up instantly and dissolved the penny in about 2 minutes. So I guess I made copper nitrate as my first experiment with it as the solution is dark blue. I continued dissolving pennies until the reaction came to a hault. I dissolved three in a very small amount of acid. If I heat this will I get crystals of copper nitrate that will stay in crystal form, or is copper nitrate highly hydroscopic? Or, should I add ammonia in small drops in a fume hood to create copper hydroxide as I need both? Which is less hydroscopic and easier to store would be the one I want now, so which is easier to store? Sorry for all the questions again and thanks in advance. I am very excited to go through all the chem's as I picked them all up late last night.

 

In my experience copper (II) nitrate is more hygroscopic than copper (II) hydroxide. That said, I find that copper (II) nitrate is more useful for reactions overall.

 

Neither are used in pyrotechnics directly, but as precursors for other salts and compounds.

 

As stated by others, it sounds as if the material you've acquired is in fine shape and useful. Congratulations on an excellent score! Enjoy your experiments, but please be careful (and tell us all about it ).

 

WSM

Edited July 1, 2013 by WSM

[TommyP]

Thank you all for the response and info. I was curious as to find the percentage of nitric acid so a friend that is a lab tech took some home and did a titration to find the percentage. He came up with 85%. I was hoping for more, but because of the age and clarity I really can't complain. Also, he told me there could be a slight inaccuracy so it's possible to be as high as 90%. Earlier I said it was as clear as water and this isn't totally true. While placed in a coffee jar and looking from the side it looks totally clear, but when put in a larger proper bottle it does show an extremely slight tint of yellow while looking through the deepest parts. But as taiwunluthiers has suggested, it takes a few drops of water to prevent passivation on copper so it has to be fairly strong - and thank you for that info!

 

Mumbles, if it wouldn't be too much trouble could you point me in the right direction on finding how to purify nitric acid? I also have another smaller jug not as strong and clean I intend making more concentrated through distillation, but I don't think that will take care of the deep yellow colour. I would like to clean up as much as possible. I did look on google for a solution, but I only found a method for sulfuric acid purification using 30% peroxide and heating. Will this also work for the nitric? If not, a little tip would be highly appreciated.

 

And then... (sorry for such a long post) recently with the copper nitrate I had made out of the nitric acid and copper, I decided to add an excess amount of ammonia to it to create crystals of tetrammine copper(II)nitrate as I had successfully accomplished a while back. Unfortunately, I think I added to much ammonia as it was just a regular store bottle and highly diluted with water. It has worked in the past (same brand), but only when I added ammonia to the solution slowly until all sediment disappeared and formed a dark, deep, clear blue colour. This time I added the copper nitrate to the ammonia as I read this prevented copper hydroxide from forming and giving a better yield. I should have known as my original way never produced any copper hydroxide as long as all precipitate was dissolved. I soon realized I had made a mistake and my old way of doing it was the proper way for me as now I get no crystal formation after three days and just a useless liquid of copper nitrate. (Could putting it in the fridge work?) I guess I could just let it evaporate and create copper nitrate crystals, but I was hoping for the other complex salt TACN.

 

It seems logical to me that adding ethanol to the solution might solidify the crystals. Do you think this option might work or any other suggestions to fix my mess?

 

PS: I just wanted to let you all know I am not looking to make TACN for an explosive as I have played with it before and it seems negligible at best. I just would like a good amount of crystals to jar for my chemical collection and to say I did it.

 

Thanks all for taking the time to help!

 

 

[NeuroticNurse]

My guess would have been, so long as you stored them in shaded glass containers that their strength wouldnt have degraded significantly.

 

If the yellow tint is caused by nitrogen dioxide dissolved in it. If it bothers you, I have heard that the addition of a (VERY) small amount of urea, to the tune of 0.5g-1g of urea per litre will remove it quicksmart, as will bubbling CO2. That said, I haven't tried it myself because its never bothered me. But if you do decide to go down that path, let us know how that works, because I would be very interested in finding out of it is real or one of those urban myths.

[Mumbles]

I can't speak toward nitric acid itself, but I have used urea to decolorize attempt to stabilize some nitrated products. It works to some degree. A quick search shows that it's used to remove NOx from industrial exhaust gasses too. Again, not nitric acid, but it has precedent.

[NeuroticNurse]

I've heard of that as well. But I've never tried it myself because I'm wondering and I'm not quite sure that it wouldn't remove the NO2 only for more NO2 to come out of the HNO3 and weaken the acid.

I'd love to hear how people have gone with it if they've tried it, just that I personally never needed to bother. But I've heard of that precedent as well being used to remove NO and NO2 from Flue gas, but just not from nitric acid either.