Making Nitric Acid Without Distillation?
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- เผยแพร่เมื่อ 7 เม.ย. 2020
- After making sulfuric acid by diaphragm electrolysis more than a year ago, I've had a few requests to try making nitric acid by the same process, and have decided to give it a go in this video.
By electrolysing a solution of potassium nitrate, we slowly generate nitric acid on the anode, as a result of the electrostatic attraction between the anode and the nitrate ion, and the formation of hydrogen ions on the anode surface. Using a semi-permeable diaphragm between the two electrodes, we can isolate the nitric acid we generate, and collect it after running the cell for a day or two.
Sadly, testing the current setup for this length of time only yields about 250mL of nitric acid at a very low concentration (0.7M at best), which is not particularly useful when compared with the concentrated stuff, in fact, to dissolve copper metal I first had to concentrate the acid by a factor of 3.
In order to be a viable production method, some changes must be made to the process. Possibly, changing the volumes of the chambers, lengthening the run time, or adding a second diaphragm to prevent the reduction of nitrate ions on the cathode may improve the yield, but maybe I'll try that in another video. - วิทยาศาสตร์และเทคโนโลยี
For those that dont know the ions,electrons can pass through the clay pot but no liquid can pass through the clay pot wallls some use a sponge but a clay barrier is much better filter.
Why the copper electrode turned black:
Red clay has a ton of iron(III) oxide in it which reacts with nitric acid. As quickly as you produced nitric acid it was turning the iron(III) oxide into iron(III) nitrate. You were then performing electrolysis on the iron(III) nitrate, resulting in nitric acid in the pot and iron(II) oxide (black) moving across the "membrane" and depositing on the copper. The reason the bath turned yellow is because the iron(II) oxide will somewhat readily turn back into solvated (or eventually suspended) iron(III) oxide.
Almost all of the energy of this process went into dissolving the clay pot. Also nitric acid is really quite volatile, like hydrochloric acid, and will just disappear into the atmosphere. A decent cover over the pot would have prevented this.
I've had better luck with using graphite fiber arrow shafts as electrodes than compacted graphite. They don't degrade at all really but their electrical resistance is quite a bit higher.
where do you buy your graphite arrow shafts?
@@mr.salisbury2435 Any sporting goods store that sells hunting supplies, also just Amazon. Its arguable whether they're really "graphite" or not, but they're extruded carbon fiber/graphite. It looks like they're mostly called "carbon arrows" now. They'll probably have the tip nut and vanes glued on.
I originally bought mine as a bore for a gauss kind of mass driver that wasn't *too* conductive (compared to aluminum).
@@htomerif thank you for clarifying
Couple of points which may help out. The ionic exchange is being drastically limited by the lack of variable voltage and the distribution of current across the anode and cathode. By this I mean when current is low because of the lack of electrolytes in the distilled water it helps to increase the voltage a little to get electron excitement working quicker. When current starts flowing you can then reduce the voltage well below 12vdc. This is slower but it stops cathode and anode annihilation. Professional electrolysis is usually done at about 1.5vdc to avoid cathode/anode annihilation but it also involves better separation materials rather than clay. The shape of the anode and cathode are critical for even current distribution through the solutions otherwise you'll annihilate your equipment. Instead of dropping the anode and cathodes into the solution vertically and creating a concentration in one particular area, consider horizontally mounted rods. Take the graphite rods and drill 4 holes in them evenly spaced half way through and insert graphite pegs into the holes. Then split the source wire for the cathode into a 1 into 4 configuration and the same for the anode, connect each wire to each peg. This distributes the current and voltage across a larger surface area and increases ionic exchange significantly. Because you have a greater surface area to play with, current can be increased without causing too much damage to the graphite. Voltage can also be increased accordingly because current and voltage are distributed evenly and voltage nodes will not appear on the graphite. Pulse width modulation is also a great option for this type of work, look into that.
the decomposition of HNO3 on the anode makes this process not worth it and I do have proper ion exchange membranes.
I instead opted for the oxidation of ammonia since I found a cheap source of Pt catalyst ready made for less than 25 USD for 250cc of catalyst.
I've been looking for an alternative way to make ammonia... nice to see this....
New favorite TH-camr!Love your vids man keep it up!
I appreciate and admire folks that have the balls to admit (like you) when they’re wrong. Unlike the myriads of PhD’s in chemistry from the University of TH-cam commenting and talking shit. Great video and it forms a great basis for us the other half who are not PhD’s with a degree. 😅
As a general note for others, anode wear can be mitigated by controlling the current density the anodes see. A starting point for graphite I like is around 15 mA/sq. cm. On little cylindrical anodes like these though, this reaction would be taking weeks. I'm using blocks that are a few hundred square centimeters. I think that Scrap Science is just willing to let the wear happen to get reasonable reaction speeds.
This is going to be great for my diy lab thank you so much
I finally found an improved but more lengthy process
use a copper anode to produce copper nitrate and continiously remove KOH from the cathode compartment.
make the porous pot area the cathode compartment.
after you obtain copper nitrate crystals from the anode chamber you then run a seperate diapragm cell electrolysis run where you use graphite as the anode and steel or graphite as the cathode and you will produce copper metal in the cathode compartment which you can remove to totally remove and ions in solution to get a very high concentration of Nitric acid.
the cathode compartment ph may drop after some time so a tiny bit of sodium hydroxide may help keep it from becomming acidic if you are using steel as a cathode otherwise if its graphite then there is no problem there.
This method works for sulfuric acid too but sadly not hydrochloric acid
the copper/iron 2 chloride just gets electrolyzed into chlorine sadly
Another option would be to decompose the copper nitrate using heat like NurdRage did in his last video. In fact, the biggest problem was to get the copper nitrate, because he made it from calcium nitrate and copper sulfate, which gives very difficult to filter calcium sulfate.
Also, if you don’t have easy access to HCl, you can always make it from NaCl and H2SO4, as your method works for H2SO4 too.
@@GRBtutorials u know after so long ive made a liter of HNO3 so far and guess what my process is.
Well I found a cheap Pt catalyst sold for fireplaces 22 dollars for like A LOT 5 grams of Pt on ceramic wool which makes a volume of like 250cc which means I can make a lot of reactors.
I then created a setup using an ammonia desorber and airline regulator valves to carefully control the gas composition about the catalyst.
Wonderful! I've been purifying saltpeter which had been crystallizing on a wall of a former pigsty for a while now and I've been looking for something to do with it!
I also wondered what would happen if I were to electrolyze it so yeah, good thinking I guess.
if it requires distillation i am out, shit too expensive
@@VerbenaIDK Plenty of ways to make a homemade distillation apparatus from materials laying around.
@@ryanallen1014 Dont have anything I can use
I must say this guy rly makes science with scrap. Nice work
Thanks for your effort and resource
You can use iron anode in KNO3 to make Fe(NO3)3 and make KOH in the cathode compartment. Then take the Fe(NO3)3 solution and distill HNO3 off leaving Fe(OH)3 in the distilling flask.
Nice idea!
I might give that a go at some point, but if we're going as far as distillation anyway, I'll probably just go for distilling the potassium nitrate over sulfuric acid.
> distill HNO3 off leaving Fe(OH)3 in the distilling flask
sir how are u going to distill? electrolysis?
Found platinum anodes that test as platinum (platinum coated titanium) for 13 USD - 3x4 inch mesh anode with handle. It is more effecient and cleaner, but works great. Carbon rods are my personal second to that one.
I gave this experiment a try, using two small clay pots and a couple of platinum electrodes. Both were the platinum-plated expanded titanium type measuring roughly 4 square inches. I started with a dilute solution of 100G of KNO3 in about 2.5 liters of distilled water, and distilled water in the red clay pots. I used an adjustable digital-display power supply capable of limiting both current and voltage.
I set initial voltage to 8V without a current limit. The anode side became strongly acidic in a very short time once the current ramped up; and the cathode side very strongly basic. My yield of very dilute nitric acid appeared to be fairly pure but with a pink tint probably caused by the material of the pot, and similar in ultimate quantity to yours, after about 40~45 hours of electrolysis. I used the opportunity to experiment quite a bit with voltage and current limits, so it's not possible to give better than a ballpark account of those parameters; I'd say most of the electrolysis was conducted at around 5V and 200mA. I found that if I limited current to 100mA, voltage tended to stabilize at about 3.9V with minimal gas production at the electrodes. Higher current got higher voltage (unless it were limited) and a lot more gas. I stopped the process rather early. I'm sure I did not consume all of the 100grams of KNO3 with which I started. I also boiled down a large volume of water taken from the cathode side, which yielded a gram or so of what must be fairly pure KOH, which of course refuses to dry fully over moderate heat. Incidentally the cathode side didn't appear to lose a significant amount of water.
Likely because my KNO3 wasn't very pure, the KNO3 solution that was NOT inside either of the pots became slimy and cloudy, with a pH of about 9. The KNO3 had come from stump remover, so it contained unknown anti-caking agents. This, and my desire to move on to boiling down my products, prompted me to end the electrolysis early. So I can't really assign anything remotely like a percentage yield.
Presumably this method would produce copper nitrate if a sacrificial copper anode were used. I'm thinking there's a chance that rather than liberating a lot of NO2 as happens when copper is directly added to nitric acid, the NO2 might have a chance to go into solution and thence produce the metal nitrate more efficiently. I'm going to give that a try next. I'll use much purer KNO3. Hopefully the process itself will provide a means to know when the electrolysis is done. I would expect the copper to stop eroding when the KNO3 has been consumed.
Where did you get the pots from?
@@yasyasmarangoz3577 Walmart! It's a seasonal item. About 12cm wide and high. Same as this:
www.walmart.com/ip/5-5-Clay-Pots-Great-for-Plants-and-Crafts/150223887
how is it going?
any success with it?
@@VerbenaIDK Yes, it works well.
The pots are porous enough that there is evident seepage from both pots into the main electrolyte bath. It helps, and it keeps the process going, to extract most of the contents of the pots at intervals and replace with distilled water, thus minimizing that seepage loss. Using copper as the anode makes copper nitrate, and produces no detectable odors or emissions aside from some bubbling of hydrogen at the negative electrode. I ran the experiment at about 3~5 volts .5~1 amp using a copper anode consisting of 10 gauge solid electrical wire for about a week (which consumed a significant amount of wire) which produced, after evaporation of the anode-pot solution, something like 40 grams of very pretty blue copper nitrate, which appears to be quite pure.
When I stopped the experiment, the main bath contained a good deal of "fluffy" mostly-greenish material, apparently consisting of copper hydroxide, probably some copper carbonate from exposure to CO2 in air, AND a dark-brown heavy residue of copper oxide. Experimentally, I tried adding to the electrolyte some of the dilute nitric acid I had extracted from the anode side, and 100% of the material dissolved into copper nitrate, turning the solution a perfectly clear very acidic dilute blue. To then remove the copper, I added some of the KOH that had been extracted from the cathode pot, carefully monitoring until pH was neutral. This resulted in a filterable green copper hydroxide precipitate which, after separation, dried to a cake of very fine dark-green powder. The remaining solution was clear and colorless. It was evaporated to recover the remainder of the potassium nitrate, which appears quite clean.
@@jamesg1367 That seems amazing!
40g I am assuming of yield, and that's a lot!
although not nitric acid, that's great!
Great upload as I'm getting back into it so I can stay home and be a chemist 👍 Now is the pot is the semi-permeable membrane? Thanx💖
Yes, you're correct about the clay pot. :)
the video i wanted thank you!!!
Could you use a aluminum cathode to push the reaction forwards by the potassium hydroxide and aluminum reacting to produce sodium aluminate and more hydrogen ions
I'm afraid not, the reaction of aluminium with potassium hydroxide does not produce hydrogen ions, but hydrogen gas instead. The reaction isn't really influenced by the presence of hydrogen ions anyway, it's pretty much just based on how many nitrate ions you can push through the diaphragm.
I love just being part of your journey into amateur chemistry by watching your videos. I do a lot of chemistry which I should create more videos of like you. I'm most obsessed with extracting elements from rocks and minerals, which is actually quite dangerous because of the many regularly encountered unknowns. It's a bit scary having to treat the hazmat as I've identified arsenic and thallium from ores I've dissolved in acids. God only knows what else I have in my bucket of various sealed unknown product containers.
Is there an easy way to extract the elements in cinnabar from everyday stuff?
@@vivimannequin If you have cinnabar, it is easy enough to extract the mercury. I think it can be displaced using carbon as a reduction agent within a sealed clay vessel. It can also be extracted using acid then cementing the product out by addition of aluminum, zinc or magnesium. Cinnabar tends to carry other contamination products like arsenic, so the mercury needs further purification through distillation. Mercury vapors are really harmful as-is so the toxicity of arsenic probably isn't much of an argument point. Just take the proper precautions as you would with any chemistry experiment to stay safe and avoid contaminating the environment.
@@mwilson14 How do you displace it with carbon?
@@vivimannequin I guess the method is to actually roast the cinnabar with quicklime I was thinking of. The easiest way then would be to roast the cinnabar with oxygen to release sulfur dioxide and mercury.
@@mwilson14 I don't have the equipment to do that though
Nice video!!
agreed! you inspired me to make my own channel
@@davisdean7481 yea your channel has potential just keep uploading and keep up the good work
There's definitely ammonia made in the cathode side. I used a platinum coated electrode on the anode side and steel on the cathode side and calcium nitrate instead of potassium nitrate. I'm glad I kept my garage well ventilated because it smells horrible.
Can you do this opposite , i mean what if you connect positive electrode to the pot and negative to the outside so only k ions would have to move in the pot and rest convert into nitric acid in plastic container outside ? Will it also work or not ?
I'm not really sure what you mean here.
If you want to switch the electrodes over and fill the pot with potassium nitrate solution (and the outer container with distilled water) to generate nitric acid in the outer compartment, you can do that.
The only problem might be the fact that osmotic transfer of water will likely make your solution in the clay pot overflow at some point.
Can you top this up with the potassium like you would a chlorate cell? I'm trying this out but I added the 2nd clay pot like you mentioned
If you're using a double clay pot system, yes! Simply add more potassium nitrate to the centre compartment as it runs.
@@ScrapScience nice I will try topping up next time. The 2 clay pot setup seems to give a slightly stronger result. I used about 200g of nitrate and the acid solution strength test devolved a spec of copper over 4 days with no heating
Where do you get potassium nitrate in Australia.
Online, mainly Ebay.
At this concentration will it react with steel if so could I supersize this with unused 55 gallon barrels and the largest garden pot I can find
Well, while it would be very likely to react with steel there, you could design the cell such that the outer area of the barrel is the cathode chamber (in fact, making the barrel itself into the cathode would allow for very high current). If you then just generate the nitric acid in the clay pot, you'd be keeping the acid away from the steel anyway.
Would it work this method to KCLO3 production , to prevent graphite erode in to the yeld?!
Separating the anode and cathode like this will turn your chlorate cell into a chloralkali cell. So no, I'm afraid you'll end up getting different reaction products, and your graphite electrode will still erode into the anode chamber.
The best technique
Do you think that Copper Nitrate could work with this method ?
You can use Gaseq to calculate the equilibrium yields of NO given compression ratio and
Fuel and air mixture.
I was wondering, since you also produced ammonia on the copper, leavening out the membrane would cause the production of ammonium nitrate right? Or would it just produce ammonia?
Most of the ammonia produced by the process will be in the form of ammonia itself (not ammonium ions). However, a very small fraction will exist as ammonium (due to equilibrium processes), which could technically be interpreted as making up ammonium nitrate in solution. In practical cases though, this ammonium content is more associated with hydroxide ions than nitrate ions.
@@ScrapScience Oh ok, I’ll look into some other methods. Thanks a lot!
Concerning your problem with the conductivity of distilled water - if you already have some HNO3, what about adding a few drops of it (or some other chemical) to the water just to _”jump start”_ the process?
From what I remember from my chemistry class was that electrolysis tends to destroy nitric acid , plus if you left your beaker on open air for 24 to 48 hours, no wonder why you lost some of it.
Is it true nitric acid can be made by pumping air past a spark (like a Jacob's ladder inside a container) then through a bubbler in distilled water?
Yep! That works.
It's not efficient, but it is rather convenient in some cases.
Maybe i missed it in one of your videos...but do you use a membrane (or plug) at the bottom of the clay pot?
Some videos I do forget to say, sorry. The pots are plugged with a stopper or a small amount of silicone sealant before use.
@@ScrapScience Thank you for the fast answer! And no problem you cant explain everything in every video ^^ keep up the great work
I am designing a process and in a stage I get copper nitrate. This method works for regenerating the nitric acid and separating it from copper?
Yep, any nitrate salt will do. In that case, you’ll also plate the copper metal onto the cathode
Grand thinking
I would like to know how to make sodium thiosulfate please reply or make a video about it
Using a slight modification of this apparatus (Porous pot in slightly bigger plastic beaker; together with platinum anode and copper cathode, and 12 volts /1.25 amps) 250 ml of nitric acid is consistently obtained - after running for only ~ 6hr. When boiled down to 50ml, this will readily dissolve copper [when heated] as in the demonstration. Sometimes there is an ammonia smell, and there is always a murky precipitate. The cell also gets quite hot.
For making sulfuric, nitric, phosphoric, acetic, hydrochloric, etc, if using the copper salts of those, is the clay pot still required? i.e. copper sulfate, copper phosphate, copper acetate, copper chloride, etc
If it isn't required when using copper salts, then is there an upper limit?
For sulfuric:
A clay pot is not required, as per my video on that topic. An upper limit exists due to the drastically decreased solubility of copper sulfate as the concentration of acid increases. I’d estimate the limit to be about 50-60% (acid concentration) but I’ve never experimented to see how far it can go.
For nitric:
A clay pot is required, as the generated solution of nitric acid should not be allowed to come into contact with the cathode (which would react with the acid to form unwanted side products).
Using copper nitrate really isn’t practically different to using any other nitrate for this process.
For phosphoric:
A clay pot is not required. This would work similarly to sulfuric acid generation, and would likely have an upper limit for the same reason. I’m not sure what kind of max concentration would be achievable for it though, I’ve never experimented with that reaction.
For acetic:
A clay pot is not required. An upper limit probably exists here from the fact that at high acid concentrations, the acid will react on the anode to form ethane and CO2. It also might suffer from the same low solubility problems as the sulfuric acid process, but I’m unsure because acetic acid is nowhere near as strong as sulfuric.
For hydrochloric:
You cannot make hydrochloric acid directly by electrolysis of a chloride salt, regardless of whether or not you use a clay pot. Chloride will preferentially react on the anode to form chlorine rather than stay in solution and allow the acid to be generated.
The only effective way to do it (somewhat indirectly) by electrolysis is to react chlorine and hydrogen gasses (made by clay pot electrolysis of NaCl) together, forming HCl gas. This reaction is very difficult to do safely however, as it is often explosive. I’ll also hopefully cover the reaction in a future video.
Why does the reaction takes lot of energy while it gives just a small amount of product ?
Would using Hydrogen Peroxide instead of distilled water in the collection chamber produce a better result?
Not by any meaningful amount. It may slightly decrease the voltage required for the process to run (since the peroxide can be oxidised by the anode instead of water), but won't change the current efficiency of the process.
What if I use a lead dioxide anode instead of a carbon or platinum one?
Definitely don’t try that. Lead dioxide, even industrially made ones, are not at all resistant to nitric acid, you’ll quickly end up generating an incredibly toxic solution of lead nitrate. Please don’t poison yourself, carbon/graphite anodes are always a safe alternative.
As the acid concentration rises
H+ goes from the anode to the cathode. The speed of H+ ions is about 10 times faster than K+.
As the HO- concentration around the cathode rises
The HO- goes to the anode.
The speed of OH- is about 9 times faster than NO3-.
So what happens is H+ + HO- = H20
at the membrane.
This is a competing reaction.
Very true.
The reaction will always exhibit this inefficiency, so it's something we just need to accept in this process, unless we want to go for ion selective membranes.
hi what if you just put organic matter in that and soak with water? wait for another day or week perhaps(?) without electricity no3 will move by itself into surrounding water
i've read somwhere porous teracota are one of the elusive things that used by many ancient chemist, in modern time they'll say catalyst and membrane
Its very similar to an process they used with peat and big clay potts filled with koke as anode and around the clay pots was an mix of peat & limestone powder and an cast iron kathode. 10V and the cells had an recistant of 3 Ohm they produced nitric acid or nitrates they added ammonia to the peat in the warming throught the current the microbes could produce more nitrate and the current seperated the ions.
Wat is that in plastic is that borax... i want to learn how to make nitric acid sir pls help me
Neat, but why doesn’t the hydroxide migrate through the semi-permeable membrane like the nitrate ions do? And what stops hydrogen ions migrating back the other way?
Yep, both hydroxide ions and hydrogen ions will migrate through the diaphragm, since it isn't an ion-selective membrane. This is the major source of inefficiency for the process.
You can prevent the transfer of hydrogen ions by using an anion selective membrane, but with a clay pot, it's just something you have to accept.
Would other nitrates work besides potassium nitrate? Also, would J-B Weld or epoxy work well for sealing the clay pot hole? What's produced on the opposite side? Is all the gas produced during the process hydrogen? And lastly, does doing the reaction longer make the yield more concentrated?
1) Yep! Any nitrate will do the job for this type of setup.
2) I'm not really sure, I've never tried J-B weld or epoxy in this process, I always stick with silicone. But I'd imagine they'd do fine in the low concentrations generated here.
3) That's actually a pretty complex question. The product on the cathode side really depends on how the cell is put together. Ideally, the cathode will generate hydrogen gas and hydroxide ions by the reduction of water, producing potassium hydroxide (which should mix with the nitrate salt which is already present in the cathode chamber). However, with this particular setup, it was observed that nitrate was being reduced to ammonia on the cathode (instead of hydrogen production). So if you set up a cell like this, ammonia will be generated on the cathode and will mix with the nitrate salt present in the cathode chamber.
There are ways to avoid the production of ammonia if you desire. Putting each electrode in its own clay pot of pure water (each of these being placed into the bath of nitrate salt solution) will ensure hydrogen is produced on the cathode. I'll be covering this method in a future video.
4) In theory, the process generates oxygen on the anode and hydrogen on the cathode (assuming inert electrodes are used) as a by-product of the acid production. However, as stated before, the hydrogen on the cathode wasn't observed in this case, so for this particular cell, oxygen is the only generated gas.
@@ScrapScience Thank you, would doing it longer make the acid more concentrated?
If sodium nitrate is used, would the other side, in theory, suppose to make sodium hydroxide.
If using 2 pots, do I put the nitrate in the milk carton and water in the clay pots? If so, the anode chamber will make crude nitric acid and cathode chamber will make crude KOH, but what will the milk carton chamber make?
If calcium nitrate is used the opposite side should make calcium hydroxide? Same with the other nitrates?
1) Running the cell longer will make more concentrated acid, yes. However, there may be a limit to the generated concentration due to the fact that nitric acid will slowly react with the clay pot separator, cancelling out the generation of acid. For all I'm aware, 0.2M concentration might be the limit when using a clay pot like this, but I'm really not sure.
2) That's correct.
3) Yes, the nitrate goes in the milk carton and water in the clay pots, generating nitric acid in the anode chamber and KOH (or another hydroxide depending on the nitrate salt) in the cathode chamber. The central chamber (milk carton section) won't actually generate anything, but will slowly be depleted of nitrate salt as nitrate ions are passed into the anode chamber and whatever present cations are passed into the cathode chamber.
4) That's also correct.
@@ScrapScience What's the time around where the cell can no longer generate any more?
Is there a more resistant membrane?
Nitric acid in such low concentration can be stored in any plastics, right?
The time before the concentration of nitric acid reaches some kind of equilibrium (assuming this upper limit of concentration actually exists) is dependent on many factors, and it's not a sharp cut-off but more of a gradual decrease in efficiency. The size of the cell components, the surface area of the separator, how concentrated the nitrate solution is, and how much current you put through the cell will all affect both the equilibrium point and how long it takes to get there. I've got no idea how to predict the desired run-time, and it's almost definitely something you'll just have to find out through trial and error. As a very rough guess, a cell like this one might go for 1-4 days before serious efficiency losses are present.
I've never experimented with any other diaphragms, but the only things I can think of to be more effective would be fritted glass, very thinly woven fibreglass matting, or a thin piece of alumina 'fire brick', if that's available to you.
You can try electolyzing N2 dissolved in water at 150 PSI. This should give HNO3 at the anode and NH3 and H2 at the cathode compartment. It is a bit dicey doing high pressure electrosis.
Yeah, I'm afraid anything involving high pressure is way beyond my skill set at this stage (probably at all stages honestly).
I'm curious, I think I've seen nitrites being used instead of nitrates you'll get Nitrous acid instead of nitric acid, and elsewhere I've seen nitrous acid will turn into nitric acid over time, so could you end up with nitric acid with sodium nitrite as the starting material?
Nitrite is easily oxidised to nitrate under anodic conditions, so you'll almost definitely still get nitric acid as a product in that case. Either way, nitrite salts are a lot more obscure (and usually more expensive) than nitrates, making the process less cost-effective.
What focus did you get this way?
What do you mean by focus?
@@ScrapScience I think the translation was supposed to be concentration. (here liquid in chemistry not light ray in optics/physics)
Where can I get the graphite ?
You can buy graphite electrodes from a welding supply store, from online, or you can get them out of zinc-carbon batteries.
LOL, I never would have ever thought I'd see the day that a pair of hands could this overact. LOL
Great work, even with the spazzie hands! Thanks for being you!
Yeah, I don't know what my hands were doing in this video, it's so crazy that I can't bring myself to watch it again honestly :)
I've switched up how I film my videos now though, so everything's a lot less hectic these days.
Glad you enjoyed it anyway!
Is it any way for homemade scale and tool to produce nitric acid from ammonia ?
On a large scale (ie. kilogram quantities) you'd need a 'nitre bed' which requires a fair bit of work and a very long time. There's also the ostwald process but that's even more challenging.
On a small (multiple gram) scale, I'm currently working on a video which does just that, by an electrochemical process. It won't be for a while though, I'm still putting together the necessary setup.
@@ScrapScience Great! Looking forward for your stet up.
OK on the cathode we have the exact reverse of the reactions in the electrolytic oxidation of ammonia video.
This makes me suspect it might be possible to make nitric acid from ammonia using a copper anode, rather than using a steel anode and copper carbonate ?
I think the two diaphram separation of potassium nitrate is the easiest way. But its going to eat anodes and probably flowerpots too.
Yep. In fact, others have tried the oxidation of ammonia to nitrate with a copper anode and have reported success. The tetraamminecopper catalyst is generated in situ, alongside the nitrate generation. The problem here is that the copper generates a LOT of the tetraammine catalyst, and while this doesn't slow down nitrate production, it does mean that the copper anode will degrade over time. Still works though.
Can't the same process be used to make Hydroiodic acid? Accept using Sodium Iodide instead?
Trying to make hydrochloric, hydrobromic, or hydroiodic acid is a lot trickier with this method. When the halides are present, the anode is able to react with them rather than water. So what ends up happening is that elemental halogens (in this case, iodine) would be formed in the anode chamber, as the iodide ions would be oxidised at the anode instead of water (which would have generated the necessary H+ ions for the acid).
@@ScrapScience -Ok thank you for the clarification!
Im so sorry i was thinking im watching the sulferic acid video so i was talking about that process 😊
Distilled water are you using? Sir
Yep
Could using hydrogen peroxide cause it to react instead of the heat?
Yep, probably. Though if your end goal is simply to dissolve copper rather than make copper nitrate specifically, you could also use a mix of peroxide and hydrochloric acid, which also does the trick and is easier to set up.
@@ScrapScience I wasn't thinking really about how it would change the cu nitrate in the end since I thought it would just disassociate
Why would nitrate ions be reduced at the cathode if they are negative? Aren't they supposed to be attracted to the positive anode?
While that's true, when the concentration of the ions is great enough, the voltage is low enough, and the surface area of the electrode is high enough, there will be enough ions around to have some always close enough to the electrode to become reduced (despite the electric field trying to push them away), especially when the reaction is thermodynamically favourable.
Would like to see the difference when using 2 pots instead of one
Brian Coit, Double the amount on nitric acid.
I don't think one would happen,i shall try and infform you all
Can I use graphite found in pencils as a anode please tell.it's lock down here so I can't buy graphite anode
You can, but you’d need to use up a lot (probably around 50) pencils to get a reasonable quantity of acid. Pencil lead doesn’t last long at all in this kind of reaction.
@@ScrapScience thank you
Yes, carbon zinc batteries have much larger, more pure sticks of graphite inside. They work much better as electrodes than pencil cores.
Would ammonium chloride work the same?
To make nitric acid? No, in the best case scenario, you'd end up generating ammonia in the cathode compartment and chlorine gas off the anode (definitely not ideal and dangerous if you don't have a fume hood). Worst case scenario, you'd end up generating small amounts of dangerously explosive compounds such as nitrogen trichloride (this is the main reason why electrolysis of ammonium chloride should always be avoided). In theory, you may get some small yield of nitrates on the anode if the salt is added to the anode chamber initially, but I'd definitely say it's not worth it to try, given the possible dangers.
@@ScrapScience Ok thank you
I would love to see you take another crack at this. Definitely not using copper, and maybe even finding a diy ion exchange membrane to use, instead of a clay pot
Hi Harry , i finally succeeded in making a toxic cloud of red nitrogen dioxide. I got the idea from Nurd Rage , using fertiliser , hydrochloric acid and copper. Now i just have to circulate it through water to make nitric acid ☺
Nice work! Let me know how it turns out
@@ScrapScience Hi Harry, yes bubbling the gas through water made nitric acid ( dilute ) as it immediately reacts with copper..I also ended up with jet black copper chloride in the reaction chamber. Tested it on copper and it immediately took a layer off the copper. What i dont understand is , How is the copper dissolving reasonably quickly in the fertilser / hydrochloric acid solution to make the nitric dioxide in the first place ?
Good luck
I like the video ☺💪👍
Well all this chemistry is home grown hahaa the chemicals are not lab or hight grade lets thank this guys for effort and im shure that a low grade nitric acid will suffice for most home experiments yeha what do you guys think cause high grade nitric acid is dangerous for the novice.
Hi mate, I have another question for you ... I did what you did with the clay pot , and i used Miracle Grow fertiliserI, I have now made Acid in the clay pot as it reacts with baking soda..But there is a number of different chemicals in Miracle Grow. Would this be nitric acid or some other sort of acid ? As my garage now has a strong smell of chlorine. 😣
Seeing as the fertiliser is a big mix of chemicals, it’s likely that the acid you’ve made is a mix of nitric, sulfuric, and phosphoric acid, as this process pretty much just generates the acids corresponding to each present anion. The chlorine smell is likely due to chlorides in the fertiliser (the chloride anion is an exception, as the anode will generate chlorine gas from it rather than make HCl).
If you’re really keen, you could react your acid product with calcium carbonate, and then filter off the insolubles. That way you’d have a pretty pure solution of calcium nitrate, which you could put through the electrolysis process once again to get more pure nitric acid. The yield would likely be very low though.
@@ScrapScience Ok Thank you for your reply... Im wondering also if i do your method using straight cloudy ammonia in the cathode side and putting something over the cathode , would that produce and collect nitrous dioxide gas ? 🤔
I'm afraid not, firstly, reduction occurs on the cathode, not oxidation, so ammonia definitely won't be oxidised to any other products in the cathode chamber. Even if it were put in the anode chamber, you have three things working against you. The main one being the fact that ammonia (or the ammonium ion) doesn't oxidise to NO2, but instead to NO3-. Also, ammonia is not very conductive and the ammonium ions are repelled by the anode, severely hindering the desired reaction.
You're much more likely to simply generate hydrogen (on the cathode) and oxygen (or possibly small amounts of nitrogen and nitrate on the anode) by the electrolysis of ammonia, whether or not you have a pot separating the electrodes.
@@ScrapScience Bugger... lol... There has to be an easier way 🤔
15:07 it should be mixture of Ammonium and Potassium hydroxide .
It's great idea thanks for that ,
what is membrane made of
It's just a simple terracotta clay pot
If a higher power supply was used would it speed up the process ?
Yep, the reaction rate is proportional to the current through the cell, which in turn is based on voltage. A higher voltage supply (provided it can keep up with the current the cell draws) will make the reaction quicker. However, it will also cause carbon anodes to disintegrate much quicker, but they're cheap so it shouldn't matter too much.
Will this work with amonia nitrate?
Yep! Do keep note that the yield is just as terrible though.
nice
Amazing method!
I have a background in chemistry, worked in a laboratory but I never have heart of this. I'm going to try this method myself. Seeign if it is possible to make hydrochloric acid from regular table salt NaCl.
You can make it, by reacting it with sulfuric-acid or sodium-bisulfate ane then distilling it
what percentage of nitric acid would this be ?
The electrolysis generated a concentration of around 1% or 2% probably
for electrodes, what about MMO electrodes? Will they rot, too?
I'm honestly not sure. Maybe the MMO itself would be fine, but the titanium substrate probably couldn't handle any reasonable concentrations of nitric acid. I personally wouldn't risk it, given how expensive MMO electrodes are.
@@ScrapScience IDK, I'm making sodium chlorate with some MMOs, and was wondering what else I could do.
maybe shoulda just went ahead and got platinum plated electrodes.
Yeah, I'm afraid MMO is excellent at performing oxidation reactions in neutral chloride solutions, but pretty terrible for anything else (though it depends on what type of MMO you have, I suppose).
@@ScrapScience ruthenium-iridium
@@ScrapScience would platinum plated titanium work?
"hello, you can see me in the reflection" don't know why I found that so funny, lel
Does it work with amonia nitrate?
Yep, any nitrate salt will do.
Do you think Calcium Nitrate would work?
Yep, calcium nitrate will do just as well as any other nitrate salt
I think the clay should perform as a barrier means to devide the medium of the container by 2 and to create the clay wall there but it must complete act as an water ion exchange but not sulfate ions from the other side this means the sulfate ions should stay on one side only not get to the other but water ions can move freely between the two sides of the membrane
One side is water and one side the solution of mgso4 dissolved in it and the electrodes must be isolated from one other and then start the hydrolysis
What is the white thing in the bottom of the pot?
It’s a small amount of silicone sealant for plugging the hole in the pot
@@ScrapScience Thank you, by the way is there any other material besides the pot that what still work?
I’ve never found anything quite as cheap and effective as a clay pot, but anything porous and inert should do the job. You could probably rig something up with some fine fibreglass or filter paper to separate the electrodes, I’m not too sure how good the efficiency would be though.
@@ScrapScience Filter paper? Will nitric acid dissolve it?
@@changweihsu Only highly concentrated nitric acid could have a chance at dissolving paper, so the concentrations achieved by this method won't be a problem.
I wonder if electrolyzing epsom salts like this would work for making sulfuric acid...
If you check the most popular video on my channel, you might see an experiment trying exactly that :)
(I will warn you though, I made the video when I was sixteen or something and I'm really not proud of it)
🙏🙏🙏🙏❤️ GOD BLESSED
you can use membrane permiablity proton it is polymere (perfulorure polyethylene glycole)
Cation exchange membranes don't work for transporting anions like this. I'm afraid those membranes won't work for this particular case.
Suppose you have the potassium nitrate solution and distilled water at below, or the same level during electrolysis changing or reducing osmotic pressure.
Can ammonium nitrate be substituted for potassium nitrate????
Yep! But the process is just as inefficient
@@ScrapScience much appreciated ☺️☺️☺️
Would you like to revisit this with two clay pots? One inside the other. I think your yeild will improve.
Furthermore, what if you coil the copper cathode around the outside clay pot a few times and place the anode directly in the center.
I hypothesize that:
1) will provide a more uniform electric field around the pots; and
2) a more uniform electric field will help better push and pull on the ions into their seperate containers; and
3) ion penetration will happen over a larger area of both pots reducing the resistance in the cell; and
4) A lower resistance will let you lower the applied voltage and that will improve the efficency.
I'll definitely be revisiting this process in the future, I'm planning on it being a future video of my diaphragm electrolysis series. Two diaphragms instead of one is the plan to improve efficiency.
The shape of the actual electric field itself isn't really a factor on efficiency, as the reaction rate and efficiency are solely determined by the cell current and it's relation to the cell voltage rather than where the ions are moving. You're 100% correct on points 3 and 4 though, plus the effect of lowering current density on the cathode will further lower resistance and increase efficiency.
@@ScrapScience I am sooooooo looking forward to your next video.
I think point 3 (ion penetration over a larger area of the pot diaphragm) happens because the geometry creates a shaper field gradient "all around" the cell that better pushes and pulles ions over a larger area and better prevents diffusion mixing.
Can we make sulfur??
Nah man just buy that it costs next to nothing
I think your a bit hard on yourself regarding the nitric acid concentration result. I think your method is quite innovative and more realistic to the common man. If boiling the end result is the only extra step then I'm in for sure. Great video and thanks for taking the time.
Doesn't the nitric Acid react with the clay ?
Not at these very low concentrations, it would have to be much, much more concentrated for any reaction to occur, and that's if it does react at all, terracotta is surprisingly resistant.
Water surrounds the pot from all sides which means the diaphram membrane effect didnt work because the clay should perform as a barrier in the electrolyte but when the pot is inside the container this means the same process keep repeating itself.or the product I being created and neutralised at same time
I wonder if anyone has used oil as a barrier in one of the u shaped pipes for electro chemistry, all you would have to do is add something like a stick of graphite that goes through the oil to complete the circuit
I'm not quite sure what you mean, oil is essentially an insulator and won't dissolve ionic compounds, so it can't be used to conduct electricity in an electrolytic cell either as an electrolyte or as a diaphragm/membrane. Or are you talking about a different mechanism?
@@ScrapScience That's why you use graphite, first put in salt water, then a layer of oil on each side put in the graphite rods on both sides to create a bridge through the insulators then top it off with the liquid you want to change
The clay pot is a membrane that lets IONS flow, not only electricity. Oil won't work.
@@EdwardTriesToScience I thought it was the electrons flowing while blocking the ions that do the work
Oops i have connected this the wrong way around, so why is my carbon rod bubbling in the clay pot ? What am i making ?
You'll simply be reducing water into hydrogen gas, so nothing bad happens when you connect it the wrong way. Provided you reconnect it properly soon afterwards, you won't make anything other than the hydrogen bubbling off the carbon rod.
woooooooo..good job!!!!! them clay pots are such a good idea..my go to for sure!!!
Does this have to be distilled water?
will it still work with normal tap water?
It will work with tap water, but depending on which minerals are in your tap water, it won’t be particularly pure
ok thanks!
@@ScrapScience How about bottles water?
@@changweihsu bottled water would do fine, but it's honestly not going to be much more pure than tap water (unless your tap water is particularly hardened or has other high levels of impurities).
Humphry Davy managed to produce tiny amounts of nitric acid in water due to dilute amounts of dissolved nitrogen gas in distilled water. But he was using platinum wire which could have acted as a catalyst for the nitrogen to react with the oxygen and then dissolved into the water. I was thinking that if you were to pump pure nitrogen near the platinum anode, you could get some detectable amount of nitric acid.
Edit: Not to mention he was pumping like 200 volts dc through the distilled water.
Yep! That's one of my all-time favourite experiments actually.
The reaction is generally understood to generate ammonia first - nitrogen gas is reduced on the cathode and then the ammonia is oxidised to nitrate on the anode. Usually, it's the ammonia people care about, but the reaction has remained a novel and somewhat useless process for the last 200 years (due to the extremely low efficiency and high energy/pressure requirements).
It's only in the last couple of years that chemical research has been capable of making the reaction efficient and reliable. In fact, the most recent breakthrough was published only a few months ago:
doi.org/10.1126/science.abg2371
@@ScrapScience thanks for the paper
How much % nitit acid can make by this method...(precentage solution)...68%...,???
This process made a nitric acid concentration of 1-2%, which is not very useful in almost all cases. However, I'm confident that the process can be improved and in the future I'll be attempting to make it better.
Azeotropic acid is definitely not obtainable by this method without an additional distillation step though. I'd be very surprised if anything over 30% could be made, even with the best optimisations of the process.
If you are real ambitious you can bud a reactor out of pipes
And gun barrels
And steel rods with 3 combustion chambers. One on each end and one at the center. The two pistons come forward to compress the reaction mixture in the center combustion chamber. In this way you can get much higher temperatures. The rapid cooling freezes the NO composition at the higher equilibrium temperature.
Can't even obtain potassium nitrate over here without going onto a watch list thanks to the IRA.
Which is a shame because nitric is useful for alot of chemistry, gold refinement and etching.
Know of any process to get nitrates for a home chemist in nanny states beyond the birkeland eyde process
The Ostwald process is one possibility. ( th-cam.com/video/dMV4-CxCyL0/w-d-xo.html and th-cam.com/video/iaNSH89gpPk/w-d-xo.html )
Ammonium sulfate fertilizer can be used as a source of ammonia, with sodium hydroxide. ( th-cam.com/video/gh4gGkk74iU/w-d-xo.html )
Whta a wsate of ym tmie