I think I made something new but I have no idea.

[somerandomname]

I was trying to make sulfuric acid from the sulfur in pyrite when somewhere along the way something odd happened. I was dissolving the pyrite in nitric acid while heating it around the nitric acid's boiling point to get a yellowish solution that I am not sure what it is, but I would imagine that it is some mixture of sulfur and something else. I let this happen until there was no more NO₂ being released and a satisfactory amount of the pyrite was dissolved. A small, clear salt was formed during this and everything was filtered so I was left with the yellow solution.

This is the point where this mystery starts. I boiled the solution to make sure none or little water was in it so I was left with a fairly concentrated amount of the solution. I then put about 5ml in a grad cylinder and dropped in 2ml of copper nitrate just for fun. When it made contact with the solution, it started bubbling a bit then stopped (99% sure the copper nitrate had nothing to do with the reaction that is about to happen since the same thing happened without it). I then wanted to see what would happen if it made contact with a base, as up to this point I was unsure of its pH so I added some bleach, and immediately it rapidly shot up and released a very orange foam spilling on the ground. I went to touch the glass to see how it felt and it was fairly cold. I have two questions that I would like answered: What the solution was made of when the pyrite dissolved in nitric acid after being boiled and if I just accidentally created elephant's toothpaste that had sulfur in it?

Edited June 30, 2022 by somerandomname
forgot something

[somerandomname]

UPDATE Always use face protection and long sleeves when doing something you've never done:

Ok, so I still don't know what the sulfur solution is but I did find something interesting about it when I made a new batch. This time I used twice as much nitric acid and 3.5 times as much pyrite. When everything was done it was much redder than the original, probably due to a higher iron concentration. I attempted to recreate what I did originally but in larger amounts so I put in 20ml of the solution into a grad cylinder again and added 10ml of bleach but nothing happened except some chlorine gas was made (Did not happen last time. Probably just didn't get enough of the nitric acid out). The bright idea came to my stupid brain to put some 50% sodium hydroxide solution in it to see if it would make more of a difference. It did exactly what happened originally but a blood red color instead. I then got another grad cylinder and put the same amount of the sulfur solution in and drop in some of the sodium hydroxide. BIG MISTAKE! You could say that the reaction did not like being in the cylinder so it decided to leave. Violently. The glass exploded with the unknown mixture flying everywhere and falling down later getting over my coat and my legs. If I knew that would happen I would have wore pants I swear. But yeah, this just makes me even more confused as to what the sulfur solution could be.

[exchemist]

42 minutes ago, somerandomname said:

UPDATE Always use face protection and long sleeves when doing something you've never done:

Ok, so I still don't know what the sulfur solution is but I did find something interesting about it when I made a new batch. This time I used twice as much nitric acid and 3.5 times as much pyrite. When everything was done it was much redder than the original, probably due to a higher iron concentration. I attempted to recreate what I did originally but in larger amounts so I put in 20ml of the solution into a grad cylinder again and added 10ml of bleach but nothing happened except some chlorine gas was made (Did not happen last time. Probably just didn't get enough of the nitric acid out). The bright idea came to my stupid brain to put some 50% sodium hydroxide solution in it to see if it would make more of a difference. It did exactly what happened originally but a blood red color instead. I then got another grad cylinder and put the same amount of the sulfur solution in and drop in some of the sodium hydroxide. BIG MISTAKE! You could say that the reaction did not like being in the cylinder so it decided to leave. Violently. The glass exploded with the unknown mixture flying everywhere and falling down later getting over my coat and my legs. If I knew that would happen I would have wore pants I swear. But yeah, this just makes me even more confused as to what the sulfur solution could be.

I don't know the reactions of pyrite but found this paper: https://www.mdpi.com/1996-1944/15/12/4181/html which suggests the product of oxidation of pyrite with nitric acid may be FeSO4 and elemental sulphur:

FeS_2(s) + 8 HNO_3(aq) → Fe²⁺_(aq) + SO₄²⁻_(aq) + S⁰_(s) + 8 NO_2(g) + 4 H₂O_(aq) 

 

But the way you are going about this is not very scientific - and not at all safe, as you have now found out. Why are you adding "bleach" and what is the chemistry of this bleach? Doing that is not going to help you determine what is in your yellow or reddish solution, is it? I think you need to weigh the quantities and calculate how much nitric acid to add, knowing its concentration, then test the resulting solution with pH paper before going any further. Then think about what else you might test for to see what is present. If you have excess acid and you start chucking in NaOH, or something nitric acid can decompose (like the hypochlorite often used in bleaches), you are asking for a trip to hospital. Eyesight is a precious thing. 

It's great you are having fun with chemistry but please take care. Test with small quantities, in vessels with wide necks (not a graduated cylinder), so any sudden evolution of gas or heat can escape and with plenty of ventilation or in the open air if you are trying this at home. Gloves, face protection and long sleeves strongly recommended, as you say.

Edited July 1, 2022 by exchemist

[somerandomname]

Thank you for that paper. I do agree with you that what I was doing was very unsafe and should not mix things together when you don't know what they are and how they react. I pulled this experiment off of my main one I was doing, which was done in a much safer manner than this one. I'll take your advice with the pH papers and looking back, it does seem pretty silly doing what I did. About the bleach thing, the reason I was using that is because I wanted to use a fairly tame base, but honestly I should not have added anything at all, especially considering it produces a bit of chlorine. It may not seem like it from my post, but safety is my most important factor so I try to be in ventilated areas and 100% of the time I wear some kind of glasses and coat.

[exchemist]

1 hour ago, somerandomname said:

Thank you for that paper. I do agree with you that what I was doing was very unsafe and should not mix things together when you don't know what they are and how they react. I pulled this experiment off of my main one I was doing, which was done in a much safer manner than this one. I'll take your advice with the pH papers and looking back, it does seem pretty silly doing what I did. About the bleach thing, the reason I was using that is because I wanted to use a fairly tame base, but honestly I should not have added anything at all, especially considering it produces a bit of chlorine. It may not seem like it from my post, but safety is my most important factor so I try to be in ventilated areas and 100% of the time I wear some kind of glasses and coat.

Bleach is a terrible choice if you're just wanting a weak base, as it is highly reactive in its own right and can evolve poisonous gas (Cl2). A good weak base is something like baking soda, NaHCO3. That will fizz and evolve CO2 in contact with an acid, but all it does to what remains is to introduce some Na+ ions.  

What intrigues me about the reaction is the possibility of producing some elemental sulphur. That will be insoluble in aqueous solution so you should get some kind of yellow precipitate if you let it all settle.  

[somerandomname]

Update 2:

Looking back I can't read what I wrote. I just sound so stupid. I eventually figured out everything I needed to know, turns out I completely forgot the basics of how this stuff works. I doubt many people will see this but please do research before you do something and not look like a complete fool.

[Bufofrog]

13 hours ago, somerandomname said:

Update 2:

Looking back I can't read what I wrote. I just sound so stupid. I eventually figured out everything I needed to know, turns out I completely forgot the basics of how this stuff works. I doubt many people will see this but please do research before you do something and not look like a complete fool.

You ran an experiment, made a mistake and are now disregarding the flawed results.  That doesn't sound stupid at all (+1).