Purifying Hydrochloric Acid 

@Extractions&ire you mean, explosions is supposed to be writing his thesis.

What's the backstory on the disgust for yellow? I haven't managed to find out exactly why he doesn't like it.

Yes

Yeah I think it is too. It's soluble in hydrochloric acid but not water, so when pH is increased it precipitates.

Bubbling vapors from hot hcl is a poor way of generating hcl gas. Its azeotrope with water is 20%... So 80% of the vapor is water. A better solution is use a ported flask and a funnel with a stopcock. Put regular table salt into the flask and put sulfuric acid into the funnel, adjust the stopcock valve to slowly drip the acid onto the salt. Pure hcl gas will be generated this way. After its been going for a few seconds all of the air in the flask will be pushed out and you can run a tube from the port to your reactor to bubble 100% hcl into.... Hows the saying go.... Cleanliness is next to godliness 😇😎

@@idontknowmyfirstname69 Because HCl builds an azeotrop you definitly CAN drive out the gas from a hot CONCENTRATED hydrochlorid acid. Until its concentration reached 20 % only the gas and nearly no water will come over. If you bubble the gas in COOL 20 % destilled hydrochloric acid, you will get a pure AND contrateted acid! Surely you can also use NaCl and (if you are allowed to in your country...) conc. H2SO4 or easier available NaHSO4 by heating (I just made a video of this method), but why should we use three reagents, when one is also sufficient? 😉

@@experimental_chemistrynow i don't disagree with you but in essence this is a simple distillation we are discussing. You were absolutely right but an actual practice when you have a mixture of two liquids in a solution and distilling the one off of the other when both of their individual boiling temperatures are that close you almost always tend to bring a little bit of one with the other even before it reaches its Asian trope. Personally I avoid distilling HCL it is a god-awful gas that I have got alone full of once and I intend to never again but I have found this short of using reflux column doing a fractional distillation whether I'm distilling ethanol from water or nitric acid from water for HCL from water I found that it always brings a little bit with it even before it hits your true now as far as concentrations go around here it's kind of hit and miss a lot of the products aren't labeled some are as high as 3132% concentration others are 18 to 20% concentration most of which all have organic buffers of some kind some even have detergents in them most won't even tell you what their percentage of concentration is on the bottle you have to look up the data safety sheet I prefer not to leave anything to chance

@@idontknowmyfirstname69 I guess you are principally right, too. It's was just an idea to keep things simple also in increasing the concentration. And never forget to use an inverted funnel when bubbling HCl in liquids containing water... 😉 I tried my method years ago just for fun without any need: in my country you can get relatively pure AND stable concentrated hydrochloric acid in every hardwarestore. It tended to have 24 or 32 % HCl and that's really true - I have tested it by titration. You must have just one thing in focus: don't buy it when it looks yellow. There are enough stores that sell good colourless stuff... A so heavy contaminated acid like Harry's I've never seen here...

I agree with you on HCl bottles leaking acid vapor that will rust every bit of steel or iron in a room.

Yes, an excess of frustration also describes exactly what I’ve experienced, haha.

Woah, electrochemistry with mercury, I'll look forward to seeing it! Honestly, I've never worked with mercury in electrochemistry, nor have I even worked with it at all (aside from one time in high school when my friend and I broke open 100 tilt switches to extract the metal, but that's another story). As a result, I'm not going to be able to give you any practical knowledge here, but nonetheless, there are a few things I'm able to tell you before you start: 1) Yes, I would imagine that electrolysis of any mercury(II) solution would give you mercury on the cathode. Since the oxidation states of mercury are (relatively) simple, and the reduction potential is very high, there's not much that would prevent this from occurring. 2) For your electrodes, You've got different options to pick for your cathode and anode. Since your goal is to make metallic mercury, I assume you'll probably want a cathode which won't be amalgamated by the mercury as it forms. As you might guess, iron is probably a good choice here, though it does have a very low overpotential for hydrogen generation, especially in acidic conditions, which may prevent mercury from being formed (this is very unlikely, but a possible issue). If iron doesn't work, copper should be a good choice, though it will slowly be amalgamated of course. Graphite/carbon may also be a good option. As for your anode, since you're doing this in an acidic solution containing chloride ions, there's only one choice for an anode that won't passivate or contaminate your solution. This is graphite or carbon. It will likely disintegrate and fill your solution with graphite dust as you electrolyse, but there will be no chemical contamination introduced to either your solution or your metallic product, so in my opinion, it's the only valid choice. 3) As a result of electrolysing an acidic solution containing chloride ions, you're going to generate chlorine gas on the graphite anode. Obviously it's nothing you can't deal with, but be prepared to generate a lot of it as a by-product of the reaction. 4) A much bigger safety concern than the generation of chlorine is the generation of aerosolised solution. Since you're generating chlorine on the anode, you'll get the gas coming off the electrode in the form of microbubbles (a common thing to happen in electrolysis reactions), which will throw invisibly small droplets of solution EVERYWHERE. Seriously, it's quite amazing how far this aerosol can travel. From what I've seen of your videos, you appreciate safety measures to a high extent, and I'm sure you'll agree with me when I say that an aerosol of mercury solution would be my absolute worst nightmare! You're probably planning on doing this anyway, but it is essential to perform the reaction in some kind of semi-contained vessel, lest you fill the air with mercury salts. This might be a tricky thing to do since your vessel will probably fill with chlorine as you perform the reaction, but maybe something like Nurdrage's 'electrolysis box' project might work well (possibly with the addition of a constant airflow through it, with some kind of filter to catch the aerosol?). 5) Another thing to remember is that if you're going to use a cathode like iron or copper, it's important to never leave the electrodes in the solution while they're unconnected to your power supply. As you're aware from your 'Recycling mercury from Hg containing solution' video, these metals will replace the mercury in solution when they're not cathodically protected by the voltage you apply, and will contaminate your solution if you turn the power off. 6) I find this unlikely, but it's entirely possible that you might make mercury(I) ions as a by-product of the cathode reaction. I'm not sure what would happen here, since I'm unaware of general mercury chemistry, but maybe mercurous chloride would precipitate? Or maybe mercury(I) ions are unstable in acidic conditions, I don't know. Just be aware that if mercury(I) ions are at all stable in your solution, there's a chance they might be made instead of metallic mercury. 7) If you find that your electrolysis process just doesn't make any mercury at all, and instead makes hydrogen on the cathode, it might be because your solution is too acidic, or some kind of ligand effect is interfering with the reduction of the mercury (Does mercury exist in some stange complex here? Again I'm not sure what's happening with the mercury chemistry). I find it extremely unlikely, but if you don't see any mercury being made, these issues are likely to be the cause. Not really sure how you'd fix these issues, so it's best to just hope they don't happen. 8) The anode reaction will remove chloride ions from solution. Will this possibly decrease the solubility of mercury sulfate as time goes on? You'd definitely know more than me in this regard, so I'll leave the implications of this one to you. 9) Finally, if you want your mercury product to be pure, ensure that there are NO other metallic ions in solution. Mercury has quite an amazing electrochemical ability to reduce pretty much any metallic ion when used as a cathode. Seriously, even if you have sodium ions in solution, the mercury you make on the cathode will allow for the generation of sodium metal on the electrode surface, and you'll end up with a mercury-sodium amalgam. Similar stories follow for pretty much every single other metallic ion, so avoid them all if you can. I feel like I got a little carried away there, and you probably know most of these things already, but that's pretty much all I have to say. Hope it helps, and I wish you the best of luck with your mercury extraction!

only pour Zn or Al or Mg powder into Hg solution, so the Hg precipitate, no energy, no electrochemistry, just ionic interchange.

SOLUBILITY RULES: All Nitrates are soluble All chlorides are soluble, except Ag2Cl2, HgCl, PbCl2*; *it is a little bit soluble

The excess HCl gas can be absorbed in the distillate if you cool the receiver flask with ice. Major impurity in crude HCl is iron and calcium (I presume, but it depends on source)

@@janami-dharmam That should work too and be so simple. Fpr getting 16% solution it is enough to just put in a closed space open beaker of 32% and another beaker with distilled water. At same temp. you'll get 50/50 distribution of hcl to similar amount of water. Very high solubility of HCl gives you so many unusual options.

@@hoggif this too is a form of distillation and works best if (i) air is removed first and (ii) both the vessels are kept on a metal block so that isothermal condition is maintained.

@@janami-dharmam I would not consider a deistillation when it is about dissolved gas escaping or evaporation without boiling. It would be mo effective if HCl source is how (high vapor pressure) and receiver cold (lower vapor pressure and gases dissolve more). Similar temperature is not optimal but temperature difference is often difficult to maintain for a long period.

@@hoggif You forgot the density of hydrochloric acid. 1 ml isn't 1 g. 32 % has a d. of 1,16 g/l, 16 % 1,08 g/l. So you have got to take a smaller volume, if you want to get the correct concentration. Acid isn't moonshine, whose concentration is messured in vol. ;-)

Do two batches and put the first in the scrubber, that'll raise the concentration rather than wasting the excess HCl.

As a matter of fact, I'm in Australia too. And the swimming pool HCl you're talking about is exactly the acid I used in this video (I only store it in one of these black bottles because it's easier to pour from). There's definitely impurity in there, even if it's not visibly obvious.

As a matter of fact, the acid I use in this video is actually from the white bottles from Bunnings (I buy it in the 5 litre containers and then put some of it into this black bottle because it’s easier to pour from). In my experience, there’s little to no difference between the two products (maybe the white bottles have slightly less iron, but it’s pretty much negligible).

​@@ScrapScienceWe used the pool version to experiment with replacing the sulfuric acid with HCl in the carbon snake experiment... had to add heat using a hot plate and got a really odd foam instead of a "snake". Done outdoors due to fumes.

yes, it can be done. That HCl is very pure.

And do it with a laser 😁

I've been planning on doing this for a while. However, the reaction between hydrogen and chlorine can be very dangerous and explosive if not performed properly, so I'm still working my way up to trying it. The full project will probably be a long while away, sorry.

@@ScrapScience The 'very dangerous and explosive'-thing is the reason for the 'boooom' in my message. O:D Don't worry, I'm patient!

to prevent risk of explosion, pack the mixing region with glass wool (free radical chain breaker) and use weak room light.

Yep, if you try to distill the 32% stuff, it will first give off a lot of HCl fumes (which will not condense) before the concentration will decrease to the azeotrope and distill properly. I just find it easier to avoid dealing with the HCl generation, and skip straight to the azeotrope distillation. That way there’s not too much to worry about when capturing the excess gas.

@@ScrapScience yes, but if you put some plain distilled water in the flask, that HCl will happily dissolve in the solution and if you cool the flask you can get more than 20% conc

The 'always add acid to water' rule only really applies when an acid has a highly exothermic reaction upon dissolution in water. The reason we pour the acid into water in these cases is because the high heat capacity of water is capable of absorbing the heat released, and doing it the other way around would cause the mixture to heat up considerably (possibly boiling and spraying everywhere). This is most important when working with concentrated sulfuric acid or nitric acid, since they release a lot of heat when mixed with water. In the case of concentrated hydrochloric acid however, not much heat is released when diluted in water, and the heat capacity of the acid is rather high anyway (since it is already comprised of ~70% water). As such, the 'always add acid to water' rule just doesn't apply in this case, and there are no issues associated with adding water to the acid.

Around 20%. Same as the concentration we diluted it to at the start.

If we left it at 32% concentration, the first stage of the distillation would first release HCl as a gas which would not condense. It's not too hard to collect the gaseous HCl and redissolve it back into water, but it's just simpler to skip that part by distilling the azeotrope directly.

Aluminum and HCl produce hydrogen gas, not hydrogen chloride gas. A little of the HCl gas from the heated acid might carry over, but not much. Just heat the acid to drive off HCl gas. If you have access to sulfuric acid, you can produce nearly dry HCl gas by dripping the acid onto non-iodized kosher table salt.

Again I'll say it. I'm speaking from experience your quoting literature. this is a hotly debated topic among hobby chemists and on paper H2 should be the product but in reality the rxn is so exothermic a massive amount of HCL gas is produced. I've never bothered to find out how much but Its a lot.again I'm speaking from experience. Go fill a bottle 1/4 full of 35%hcl drop in some Al foil and report back

@@ryans3074 reporting back, my dicks now stuck in a coke bottle... thanks.

I could have, but this is just easier honestly. We don't lose any of the acid, we don't have to deal with any significant amounts of HCl gas, and having the acid in a slightly diluted form isn't really a big deal for hydrochloric acid.

It didn't work, but yeah, I have a whole playlist: ru-vid.com/group/PL-HKUYpPsonlaTxeaZi439nTqOcVEuVLF&si=uyLnPxxIRHjZ59QE

@@ScrapScience thanks I’ll check it out

Be extremely careful if you are even thinking of working with potassium cyanide it and solutions of it in water are highly toxic and rapidly blocks the ability of cells in the human body to intake oxygen. Potassium cyanide is also a tightly restricted chemical in most areas and countries. Please if you handle potassium cyanide be extremely careful with it. Ammonia gas is a toxic and corrosive gas and can burn holes in the lungs if large amounts are inhaled so please also be extremely careful handling ammonia gas

@@craigpater6278 I'm okay with ammonia, think I'll avoid KCN for now

@@SodiumInteresting yes I'm not necessarily saying that you should avoid working with ammonia gas or potassium cyanide or any other highly toxic chemicals, I'm simply saying if you do choose to do so just be very careful and use appropriate safety gear and proper safety procedures, practices and protocols

20%. I explain the azeotrope at around 1:51.

This is a common rule, but not one that actually applies under many cases. The 'always add acid to water' rule is only important when an acid has a highly exothermic reaction upon dissolution in water. The reason we pour the acid into water in these cases is because the high heat capacity of water is capable of absorbing the heat released, and doing it the other way around would cause the mixture to heat up considerably (possibly boiling and spraying everywhere). This is most important when working with concentrated sulfuric acid or nitric acid, since they release a lot of heat when mixed with water. In the case of concentrated hydrochloric acid however, not much heat is released when diluted in water, and the heat capacity of the acid is rather high anyway (since it is already comprised of ~70% water). As such, the 'always add acid to water' rule just doesn't apply at all in this case, and there are no issues associated with adding water to the acid.

@@ScrapScience I did wonder if the hardware store bought Hydrochloric was concentrated enough to be a problem with the addition of water. I use it almost everyday at my workshop to remove dross and mill scale from plasma cut steel, I usually further dilute it 20% of volume. At that strength, would you consider short term skin contact to be hazardous, probably more over long term? I quite often grab something without gloves and sure if you have a cut or other skin injury it’s not pleasant and I would typically rinse the exposed skin in a few seconds and it’s never caused any acute or chronic skin issues that I’m aware of and I can’t find anything online about it, obviously nobody is promoting washing in acid solutions for some reason 😂

Getting acid on your skin and then thoroughly washing it off in a matter of seconds will leave no long term effects. The worst thing that could happen is that your skin might get a bit dry for a while. It's always a good idea to wear gloves though. Long term contact and any exposure involving your eyes is a completely different story however.

Think about all the different color variations of the sprcies of iron oxides.... Black to brown to red to gold to yellow.... You'll get similar between the ferrous and ferric chlorides.... In refining the saying never judge a book by its cover translates to never judge a solution by its color 🤓

@@idontknowmyfirstname69 Which is why I suggested trying to test it by its partition coefficient between water and an organic solvent such as DCM, Et2O, pentane, etc. Bromine and iodine will partition into the organic phase, forming colorful solutions. Iron salts will not. You could just do it old school however by carefully wafting and sniffing the air above the beaker. If it's bromine, you'll know it soon enough. The only reason bromine even crossed my mind is the way that it and HCl are manufactured. Bromine is extracted brine wells. The brine contains a mixture of halide salts from which elemental Br2 is extracted. The leftover sodium chloride (and a little residual NaBr) is then used as feedstock for hydrochloric acid manufacture. It is likely that acid so manufactured will contain HBr as an impurity. Here's the process: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kOpC11j1u8w.html

Yes, but the efficiency will probably be terrible, and a taser isn’t built to strike an arc from long periods of time.

The easiest way to make nitrogen oxides including nitrogen dioxide is to react concentrated nitric acid and copper metal turnings or small pieces of copper metal like copper coins. But be extremely careful concentrated nitric acid is highly corrosive and is a strong oxidising agent and nitrogen dioxide is a toxic gas

Impure = 32% Pure ~= 20%

@@ScrapScience means u lost HCl in terms of concentration . Your HCl became pure but it became a lot dilute than before

Correct

The sodium hydroxide is just there to react with any acidic fumes that might make it out of the apparatus. If any acidic fumes were to escape, it would have prevented release into the atmosphere (and more importantly, my lungs). Yes, the final product is reduced in concentration.

Because that reaction would be more difficult, require the use of sulfuric acid, and would not be a quantitative reaction. The direct distillation of hydrochloric acid is simpler, doesn't involve dealing with large amounts of hydrogen chloride gas, and has the capability of recovering virtually all of the initial acid (albeit at a lower concentration). Using a more complex setup only to get a higher concentration in the end product just isn't really justified here, given how simple this was to perform.

Yeah, that's possible if you've got the time. I'm not sure what kind of concentration you'll get though (it will probably depend on the relative volumes of the acid/water you start with).

@@ScrapScience So I think if i start with a 30% concentration of HCl full of impurities and another bottle is just distilled water and the HCl gas will dissolve in this distilled water, the concentration will be 15% in the distilled water Is that how it will be?

I think it's very unlikely that chromate would be added to a chemical that is designed to be used in pools. It's perfectly possible that the colour is added for the reason you've suggested though.

I can't really diagnose the problem with the information you've given, but the most likely reason you're losing your product is because you're not keeping it cold. You need an ice bath for your collection flask, since nitrogen oxides will dissolve in water much better at low temperatures. Allowing your solution to reach boiling temperatures will drastically diminish your yield, and cause you to lose lots of your product.

@@ScrapScience thanks for replying What kind of information you want to know. I can give you any information. But the flask doesn't get very hot it's about 25~30C*. Do you think it's because of the PH I mean I can't make concentred nitric acid just by babbling NO2 gas in water!? It should be a limit for dissolving the gas(NO2) in water (10%or 20 or more 🤔) before the gas start running out of the nitric acid ( how much%of nitric acid I can reach in 100ml of water just by bubbling NO2 in it. If you can help me with that please so I can change the water each time to prevent losing NO2 gas. Thanks alot

The consumable reagents for an HCl generator are going to make that process significantly more expensive than simply distilling hydrochloric acid.

@@ScrapScience no certain I agree. Sodium bisulfate and table salt are both pretty inexpensive. The only other item needed is water.

Prices might be different for you, but I can get sodium bisulfate for about $7/kg. With a 100% yield in an HCl generator, 1 kg of sodium bisulfate can make about 300g of HCl gas, which translates to nearly a litre of concentrated HCl. As a result, this kind of generator would make concentrated HCl at a price of $7 per litre (neglecting the price of sodium chloride), which is being generous. Since I can buy concentrated HCl directly at around half that price, it's definitely simpler for me to just use this distillation method. That might just be for me though. Prices of these chemicals are rather different depending on location.

Correct. I just didn't really want to deal with trying to dissolve HCl gas in water in this case. If things went wrong or the gas were improperly absorbed, it would present a pretty big issue.

There are many plastics that don't react with HCl, so I don't really see why glass is necessary. Also, how could a small degree of exposure to air ruin the purity?

Yeah, I like that idea! Sounds like a plan.

plus is clear, dayum

!!Whaaaaaaaat?!!

17 volt 20.amps

If you achieve that, 340 watts... I hope what ever you're doing is big enough to handle the heat

@@procactus9109 Can you please givee me an explanation on how you measured it out!!! Also will this type of series connection damage any of the power supplies??

@@heisenbergstayouttamyterri1508 the voltage is simple added. The max current is the lowest current of the power supplies... Both have to be electrically isolated, ie. No common ground.. this means you can't use 5 and 12v from a single PC supply.... No damage will occur if both outputs are isolated and you don't over shoot current demand. It's a bit dodgy but will work.

@@procactus9109 Yes, I'm tryin' to say that I am using two different power supplies with different voltage and current!!! Also can a 5V 60Amp power supply be good enough for persulfate cell???

How are you suggesting to make hydrochloric acid? As far as I know, the methods of electrolytic production are difficult and require a rather complex (and somewhat dangerous) setup.

Why does it have to be ripple free? Where do I get a ripple free 27 amp source at 24 volts ?

Have you considered the fact that I might be doing this because I find it fun?

The 'always add acid to water' rule only really applies when an acid has a highly exothermic reaction upon dissolution in water. The reason we pour the acid into water in these cases is because the high heat capacity of water is capable of absorbing the heat released, and doing it the other way around would cause the mixture to heat up considerably (possibly boiling and spraying everywhere). This is most important when working with concentrated sulfuric acid or nitric acid, since they release a lot of heat when mixed with water. In the case of concentrated hydrochloric acid however, not much heat is released when diluted in water, and the heat capacity of the acid is rather high anyway (since it is already comprised of ~70% water). As such, the 'always add acid to water' rule just doesn't apply in this case, and there are no issues associated with adding water to the acid. Like many things, knowledge of 'basic chemistry' will teach you simple rules, but with knowedge of intermediate or advanced chemistry, you'll understand when these rules do and don't apply.