My son (7 at the time) did this experiment using some aluminum cans he found at the park. We started with the KOH, and sulfuric acid drain cleaner to neutralize. Went through a TON of recrystallizations to purify. We used the alum to flocculate some river water, before passing it through a homemade carbon filter (which would have been gunked up by the sediment in the water) and boiling to kill any wildlife that remained. It was delicious water. Ten years later, we still have a bunch that my son uses as a styptic for the occasional shaving cut.
I was reading something about that, I'll probably still give it a shot but from what I read it can take over a week to grow a crystal that way so I didn't include it in the video. Does it really take that long?
Neat! I've had good luck using alum solutions to dissolve broken steel taps or bolts in aluminum parts/castings without hurting the aluminum. Takes patience, but works eventually. Thanks!
I totally forgot to mention that as a use for alum (also haven't tried it myself). Glad to hear it works because that would actually be extremely useful
Which order of reaction do you think would be better if you only had lead contaminated acid available from an old car battery and wanted less lead contamination in the product?
Either one would result in some amount of lead in the final product. Recrystallizations can help, but a good way to remove lead from battery acid (If you don't want to distill it), is to run it under electrolysis with graphite electrodes. The lead sulfate will be reduced to lead metal at the cathode and you can easily filter it off or decant the clean sulfuric acid.
@@integral_chemistry Thanks for the prompt and helpful reply. That is a great idea. Some batteries have Antimony and/or calcium in the plates structure so perhaps in solution as well, not as toxic but I wonder if they would also plate out the same way to some extent?
@Apoptosis Why not trying to make sodium alum? It´s said that it is hard to crystallize because of the drastic difference between the solubility curve of aluminium sulfate and sodium sulfate.
I might just give that a shot, it should be much the same process after all. And yeah from what I read it is the most elusive of all alums because it is so insanely soluble it is nearly impossible to crystallize alone (208g/100mL at 15C)
There is a huge bunch of 🎉alums. They are the double sulfates of a trivalent metal (not a lanthanide) and a univalent metal. The trivalent metal is usually Aluminum or trivalent iron. It can also be trivalent chromium. The univalent metal can be sodium, potassium, ammonium, rubidium or cesium. The rubidium and cesium alums are much less soluble than potassium alum. So if a kilo or so of alum is dissolved in water if about 10% of it is crystalized it should carry down the cesium and rubidium present. This is repeated with the hundred or milligrams of alum. If 10 milligrams are crystalized the amount of cesium rubidium is 100 fold as concentrated. Somewhere the cesium and rubidium will show. Best results should be with technical grade alum. It was a very old book that suggested this. I would like to try it.
I only have the first method left because concentrated sulfuric acid is forbidden for private use here. I recommend adding dilute sulfuric acid until the aluminum hydroxide is completely dissolved, then concentrating the solution, refrigerating it overnight and allowing the product to crystallize and then recrystallizing again. This results in a much purer product. Pure aluminum alum crystallizes in water-clear and structured crystals. A white crystal paste filtered directly from the reaction mixture, on the other hand, can still contain a lot of potassium or aluminum sulfate or even aluminum hydroxide, especially if you worked in a non-stoichiometric approach. Excess sulfuric acid also hinders the growth of beautiful crystals. Recrystallization is always advisable and is very easy, as alum is poorly soluble in cold water. The yellow color actually comes from iron. However, it is only amphoteric in oxidation state 6. The ferrate only forms under highly oxidative conditions, which are not present here. It is also quite unstable, especially in acidic solution. In this country, aluminum foil also contains a fairly high proportion of carbon, which can be filtered off easily. The brown color of the filtration residue after dissolution in sulfuric acid comes primarily from organic impurities in the concentrated technical sulfuric acid of the drain cleaner.
Hm sulfuric acid hindering the growth of crystals would definitely explain some of the issues I had forming crystals at first.. Many of the other things you mention I figured out along the way (although I do think you're right that using dilute sulfuric acid would be the way to go), and as much as I tend to avoid recrystallizations I think I will definitely do one for all this alum since some of the crystals I've seen online are absolutely gorgeous. ... As usual you're right I should just do more recrystallizations lol One thing though I think the brown residue might be due to something in the aluminum foil itself. I'm not sure what they put in it in the US but I've gotten this same brown residue using reagent-grade sulfuric acid and HCl. I've never tried dissolving foil in nitric acid though, and it doesn't result when I dissolve the foil in caustic solutions so I'm not really sure, but it is quite annoying. My suspicion is that its some sort of organic layer that serves the same purpose that the carbon layer they use in aluminum foil serves in your country..
@@integral_chemistry Aluminum is not attacked by nitric acid because it passivates it. To make aluminum nitrate, you can only dissolve aluminum hydroxide in nitric acid. I just noticed the fade in at 0:12. Alums with manganese or vanadium are really difficult to make. Trivalent manganese is barely stable enough for this. Vanadium(III) sulfate also tends to decompose into vanadyl sulfate and is too poorly soluble in water to form double salts. But the other alums are also divas: Gallium is only badly attacked by acids. Trivalent iron in double salts is sensitive to pH, light and heat. Chrome alum is thermochromic in aqueous solutions - if the reduction of dichromate gets a little too warm, you get green chromium sulfate instead of violet chrome alum.
The two chemical equations you show look like you could put an ampule of the one stage in a long glow-stick-like container, and an ampule of the other stage in the other end of that container, and then separate them with an aluminum plug to make a simple Hot Hydrogen Balloon for use in thin, cold atmospheres, such as Mars, upper earth atmospheres, and mountaintop launches. I can see how it would also make a great ballast-to-reheat/refill cartridge for the same. Simply place a one-way valve above the stick (so H goes into the balloon, but doesn't come back out), then pop the KHO (or better yet, K metal onto an excess of water to generate the KOH+H) and use the H to top off the balloon. The KHO releases more H with the Al, and when you want to reheat the gas in the balloon, you break (this would all be done by automated/remote-controlled sprung breaker pin things from the outside) the H2SO4 ampule that's now surrounded by the mixture in the bottom. This generates an additional burst of heat, but also begins to burn through a bottom plate made of copper, or a similar material. When the plate is burned through, the spent contents spill out, relieving the system of the ballast weight, while the one-way valve at the top prevents backflow, which would deflate the balloon. Also, this may be a great compact, lightweight propellant system for long duration missions, such as probes, satellite gyro de-spinning, and trips to Mars, as it would not take nearly as much pressure tank or cryogenic tank/insulation weight, and can also provide a lot of heat for de-hibernating a system in deep space. Of course, if there is no acceleration present to separate the H and other materials so that only the gas gets ejected, the cartridge(s) would need to be in some kind of centrifuge, with some kind of expansion bulb at the top, but things in space love spinning contraptions.
Oh that's a good point! And eh fair, I've heard it pronounced both ways but only ever by people who probably don't know what they're talking about to begin with. I mostly work with/around doctors and scientists who refer to it as nothing but potassium hydroxide so "potash" to me is like calling calcium hydroxide "slaked lime" or sulfuric acid "oil of vitriol". That said, it does make sense that it would be pronounced pot-ash since potassium was discovered by burning plant material in a pot and rendering the hydroxide from the ash.
@@integral_chemistry and the word potassium stems from the english word pot-ash, not the other way round. To me, a german, it's called Kalium and hearing someone call it potassium OR potash is like calling calcium hydroxide 'slaked lime' etc. XD. The reason it has a K in the periodic table is because Martin Heinrich Klaproth called it Kalium, which comes from the word alkali which comes from arabic al-qalyah, meaning 'plant ashes'.
@@khaoliang wow okay so both "potassium", "Alkali", and "Kalium" come from the alkaline product of burning plant material? I knew that potassium came from "pot-ash" but the rest of that is new and fascinating to me.
i cry every time i see someone use metal on teflon and glassware for caustic soda reactions instead of stainless steel we'll get em next time lads.... and then americans add aluminium salts to food? this is why its usa that has to start using metric, and not europe that has to start using imperial ...
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My son (7 at the time) did this experiment using some aluminum cans he found at the park. We started with the KOH, and sulfuric acid drain cleaner to neutralize. Went through a TON of recrystallizations to purify. We used the alum to flocculate some river water, before passing it through a homemade carbon filter (which would have been gunked up by the sediment in the water) and boiling to kill any wildlife that remained. It was delicious water.
Ten years later, we still have a bunch that my son uses as a styptic for the occasional shaving cut.
I was thinking if this was the same stuff used by those wet shavers, and it seems like I was right.
You can furthermore increase the crystal's size by suspending it by a thread submerged in the mother solution, nice video!
I was reading something about that, I'll probably still give it a shot but from what I read it can take over a week to grow a crystal that way so I didn't include it in the video. Does it really take that long?
@@integral_chemistry yeah unfortunately, depends on how big you want it to be, the longer the time, the bigger the crystal
Neat! I've had good luck using alum solutions to dissolve broken steel taps or bolts in aluminum parts/castings without hurting the aluminum. Takes patience, but works eventually. Thanks!
I totally forgot to mention that as a use for alum (also haven't tried it myself). Glad to hear it works because that would actually be extremely useful
@@integral_chemistry Might be an interesting follow up, which alloys it works with and why? Maybe there's a better chemical that works faster?
I made alum using the first method in my gen-chem lab last year. That was the experiment that made me want to be a chemist :)
That's awesome! It's a super satisfying process and you can grow some pretty awesome crystals. Lots of cool jobs in inorganic chem too
Thanks
Loony Tunes taught me that drinking alum makes your mouth and face pucker up like a kissy face.
@0:16 - It's also used in canning to help keep the veg and fruits crisp.
Which order of reaction do you think would be better if you only had lead contaminated acid available from an old car battery and wanted less lead contamination in the product?
Either one would result in some amount of lead in the final product. Recrystallizations can help, but a good way to remove lead from battery acid (If you don't want to distill it), is to run it under electrolysis with graphite electrodes. The lead sulfate will be reduced to lead metal at the cathode and you can easily filter it off or decant the clean sulfuric acid.
@@integral_chemistry Thanks for the prompt and helpful reply. That is a great idea.
Some batteries have Antimony and/or calcium in the plates structure so perhaps in solution as well, not as toxic but I wonder if they would also plate out the same way to some extent?
From some very basic household items...
I see what you did there...
ha I'm glad someone noticed! Love my high-school level chem puns
@Apoptosis Why not trying to make sodium alum? It´s said that it is hard to crystallize because of the drastic difference between the solubility curve of aluminium sulfate and sodium sulfate.
I might just give that a shot, it should be much the same process after all. And yeah from what I read it is the most elusive of all alums because it is so insanely soluble it is nearly impossible to crystallize alone (208g/100mL at 15C)
There is a huge bunch of 🎉alums. They are the double sulfates of a trivalent metal (not a lanthanide) and a univalent metal. The trivalent metal is usually Aluminum or trivalent iron. It can also be trivalent chromium. The univalent metal can be sodium, potassium, ammonium, rubidium or cesium.
The rubidium and cesium alums are much less soluble than potassium alum. So if a kilo or so of alum is dissolved in water if about 10% of it is crystalized it should carry down the cesium and rubidium present. This is repeated with the hundred or milligrams of alum. If 10 milligrams are crystalized the amount of cesium rubidium is 100 fold as concentrated. Somewhere the cesium and rubidium will show. Best results should be with technical grade alum.
It was a very old book that suggested this. I would like to try it.
6 yr old erlenmeyer flask? Mine last for 20 days
Right? I tend to burn through Beakers and boiling flasks super fast
I only have the first method left because concentrated sulfuric acid is forbidden for private use here.
I recommend adding dilute sulfuric acid until the aluminum hydroxide is completely dissolved, then concentrating the solution, refrigerating it overnight and allowing the product to crystallize and then recrystallizing again. This results in a much purer product. Pure aluminum alum crystallizes in water-clear and structured crystals. A white crystal paste filtered directly from the reaction mixture, on the other hand, can still contain a lot of potassium or aluminum sulfate or even aluminum hydroxide, especially if you worked in a non-stoichiometric approach. Excess sulfuric acid also hinders the growth of beautiful crystals. Recrystallization is always advisable and is very easy, as alum is poorly soluble in cold water.
The yellow color actually comes from iron. However, it is only amphoteric in oxidation state 6. The ferrate only forms under highly oxidative conditions, which are not present here. It is also quite unstable, especially in acidic solution.
In this country, aluminum foil also contains a fairly high proportion of carbon, which can be filtered off easily.
The brown color of the filtration residue after dissolution in sulfuric acid comes primarily from organic impurities in the concentrated technical sulfuric acid of the drain cleaner.
Hm sulfuric acid hindering the growth of crystals would definitely explain some of the issues I had forming crystals at first.. Many of the other things you mention I figured out along the way (although I do think you're right that using dilute sulfuric acid would be the way to go), and as much as I tend to avoid recrystallizations I think I will definitely do one for all this alum since some of the crystals I've seen online are absolutely gorgeous.
... As usual you're right I should just do more recrystallizations lol
One thing though I think the brown residue might be due to something in the aluminum foil itself. I'm not sure what they put in it in the US but I've gotten this same brown residue using reagent-grade sulfuric acid and HCl. I've never tried dissolving foil in nitric acid though, and it doesn't result when I dissolve the foil in caustic solutions so I'm not really sure, but it is quite annoying.
My suspicion is that its some sort of organic layer that serves the same purpose that the carbon layer they use in aluminum foil serves in your country..
@@integral_chemistry
Aluminum is not attacked by nitric acid because it passivates it.
To make aluminum nitrate, you can only dissolve aluminum hydroxide in nitric acid.
I just noticed the fade in at 0:12.
Alums with manganese or vanadium are really difficult to make. Trivalent manganese is barely stable enough for this. Vanadium(III) sulfate also tends to decompose into vanadyl sulfate and is too poorly soluble in water to form double salts.
But the other alums are also divas: Gallium is only badly attacked by acids. Trivalent iron in double salts is sensitive to pH, light and heat.
Chrome alum is thermochromic in aqueous solutions - if the reduction of dichromate gets a little too warm, you get green chromium sulfate instead of violet chrome alum.
The two chemical equations you show look like you could put an ampule of the one stage in a long glow-stick-like container, and an ampule of the other stage in the other end of that container, and then separate them with an aluminum plug to make a simple Hot Hydrogen Balloon for use in thin, cold atmospheres, such as Mars, upper earth atmospheres, and mountaintop launches.
I can see how it would also make a great ballast-to-reheat/refill cartridge for the same. Simply place a one-way valve above the stick (so H goes into the balloon, but doesn't come back out), then pop the KHO (or better yet, K metal onto an excess of water to generate the KOH+H) and use the H to top off the balloon. The KHO releases more H with the Al, and when you want to reheat the gas in the balloon, you break (this would all be done by automated/remote-controlled sprung breaker pin things from the outside) the H2SO4 ampule that's now surrounded by the mixture in the bottom. This generates an additional burst of heat, but also begins to burn through a bottom plate made of copper, or a similar material. When the plate is burned through, the spent contents spill out, relieving the system of the ballast weight, while the one-way valve at the top prevents backflow, which would deflate the balloon.
Also, this may be a great compact, lightweight propellant system for long duration missions, such as probes, satellite gyro de-spinning, and trips to Mars, as it would not take nearly as much pressure tank or cryogenic tank/insulation weight, and can also provide a lot of heat for de-hibernating a system in deep space. Of course, if there is no acceleration present to separate the H and other materials so that only the gas gets ejected, the cartridge(s) would need to be in some kind of centrifuge, with some kind of expansion bulb at the top, but things in space love spinning contraptions.
extremely interesting thank you for your time. Very educational.
Exotic Alum ❤
Super! Thank you!
Please make an exotic alum: indium and ammonium or chromium and lithium
the yellow color came from passing a strong base through coffee filter
potash is pronounced pot-ash
not sure how you got that wrong
also, wouldn't hurt to link you kind sponsor
Oh that's a good point!
And eh fair, I've heard it pronounced both ways but only ever by people who probably don't know what they're talking about to begin with. I mostly work with/around doctors and scientists who refer to it as nothing but potassium hydroxide so "potash" to me is like calling calcium hydroxide "slaked lime" or sulfuric acid "oil of vitriol".
That said, it does make sense that it would be pronounced pot-ash since potassium was discovered by burning plant material in a pot and rendering the hydroxide from the ash.
@@integral_chemistry and the word potassium stems from the english word pot-ash, not the other way round. To me, a german, it's called Kalium and hearing someone call it potassium OR potash is like calling calcium hydroxide 'slaked lime' etc. XD. The reason it has a K in the periodic table is because Martin Heinrich Klaproth called it Kalium, which comes from the word alkali which comes from arabic al-qalyah, meaning 'plant ashes'.
@@khaoliang wow okay so both "potassium", "Alkali", and "Kalium" come from the alkaline product of burning plant material? I knew that potassium came from "pot-ash" but the rest of that is new and fascinating to me.
* didn't noticed anything, except the note *
"Sorry for sudden change in vocal"
Literally intolerable, boo
* replayed, still didn't noticed anything *
i cry every time i see someone use metal on teflon
and glassware for caustic soda reactions instead of stainless steel
we'll get em next time lads....
and then americans add aluminium salts to food? this is why its usa that has to start using metric, and not europe that has to start using imperial ...