Potassium Metal From Bananas!

[Applause] okay that was noisy all right everyone welcome back to cody's lab in this video i'm going to attempt to extract potassium from bananas you can see i have acquired 10 kilograms or 22 pounds of the fruit for the extraction now there is a question do i extract the potassium from the whole banana or just the part do you eat i think i would most like to see both extracted separately so we can compare the amounts weighing the peels gives me 3.44 kilograms or about 34 of the weight of the fruit i will be burning the bananas down to ash in order to have a much smaller volume of material to extract the potassium from now the banana itself has a lot of water in it it's not very flammable so to remove the water i'm going to be cutting it into thin pieces and then drying it out with this dryer here banana peels will also be dried out but to do that i'll just hang them up on a drying rack to keep the bananas from sticking together and to each other i am cutting them into a bowl of corn starch and water the corn starch does not contain potassium so it will not change the amount of potassium in the bananas but it will make it much easier to work with later on here we are the next day is now dry tail cat is making a mess just in case anyone still isn't sold on the cornstarch watch this there we are while the banana is now dried out it is so hard to keep myself from eating them these are so good i think i'm gonna go get some more bananas and make a few batches on my own after this the six and a half kilos of banana has been converted to just over one and a half and my scale just turned off that weight does include about 100 grams of corn starch so here's one of the dried banana chips here's a blow torch as you can see it doesn't stay lit turns out the bananas are very hard to burn fortunately i have an idea to make them a little bit easier since i'm going to be running my charcoal port anyway i figured i'd throw the banana chips and skins into some paint cans load them in along with the sticks so they get converted into charcoal so foreign here's the banana char put on the scale and see what it weighs looks like we're down to just under half a kilo now sounds cool it's like glass but now they should be much easier to burn because all the volatiles have been removed including every last bit of water let's uh put them back in the bag for a minute and weigh the peels as well peels 120 grams okay come outside i got a metal pan set just up put the banana chips on top of it we're gonna get a lighter fluid [Applause] and light it up [Applause] i put a chair over top of it to keep the snow off on fire and burning so here's the banana charcoal burned not all of it did burn there's still a lot of little bits of charcoal inside of this so i think to finish it off i'm going to use the furnace so i just put it in a stainless steel dish here to kind of spread it out then we'll cook it up until it's red hot use the electrical heating there are of course a few larger pieces that didn't burn i'll throw those in there as well so that's finishing i'm going to do the same thing with the peels run those dash as well it's been a couple of hours see how the banana ash is doing it's still got a little bit of carbon in it but i think we'll call that good okay so that's just under 67 grams of ash here's the ash from the peels we get 51 52 grams that's almost as much as the fruit even though the peels weighed significantly less to begin with that is interesting so here's the ash from the banana peels and the banana flesh you'll notice that this flesh ash is a little bit darker that's just because it has a little bit more carbon left over in it the peels were a lot easier to burn down that shouldn't bother things too much and let's uh dissolve out the potassium with a little bit of water i got some distilled water here let's just pour it in about yeah much get the lids back on give it a bit of a stir i'll let it settle out pour off the clear liquid assuming we get clear liquid and then i'll add some more water to kind of rinse things through all right looks like it's settling out okay so here's the banana flesh ash water containing the soluble portion of the ash so this water now contains probably mostly potassium carbonate with a little bit of sodium carbonate some hydroxides and various trace minerals you can see if i take some ph paper it is strongly alkaline but it is fairly dilute so we need to concentrate the solution some okay here it is it's cooled down a bit you can see some uh whitish material has precipitated now that is likely potassium carbonate so i'm gonna add a little bit of water just to get everything to dissolve again i've also boiled down the material taken from the banana peels i don't like how contaminated my solution is it's mostly soot and really wouldn't cause much of a problem but i'm gonna remove it so i've got this little vacuum filter set up here i'll just pull it through that should clarify the solution well it's clearer so now i've got a solution containing mostly sodium and potassium carbonate but i want just the potassium so to separate out the sodium i'm going to take advantage of the fact that the chlorate salts are usually very soluble ammonium perchlorate very soluble sodium perchlorate soluble calcium perchlorate etc but potassium perchlorate is an exception potassium chlorate is only it's very slightly soluble so if i add some ammonium chlorate to the solution potassium chlorate should fall out i'll dissolve it in water first just to make things more obvious all right here we go if potassium is present in sufficient quantity it should precipitate as a white cloud yeah that looks like it works so the ammonium chloride has been added and the potassium chlorate is settling out of solution that's about just over 200 milliliters so it is possible there's about four grams of potassium chlorate still dissolved i can reduce that by cooling it down so let's go pop this in the freezer see the potassium perchlorate is settled out of solution i'm just about to pour off the liquid on top now one thing you might have noticed is there actually appears to be more potassium in the peels see this one was from the peels and there wasn't the actual flesh of the bananas that's interesting so i'm just going to spoon this into the vacuum filter so we can remove the remaining liquid i also have some cold water to rinse with use a little bit of that rinse that cold water through so so i just baked the potassium chlorate dry now it's time to put it in my little dish and weigh it let's put it on the scale we got we got 33 grams of potassium perchlorate and let's uh weigh the potassium i extracted from the peels 41 grams from the peels so i actually recovered more potassium from the peels than the actual part of the banana that you eat yeah unless i've mixed something up it actually might make sense to eat the peel if you want potassium now there's not really any reason to keep these separated anymore let's just combine the two there's all the potassium i extracted from the bananas of course this is still not pure potassium it's over half oxygen for one so i'm going to remove the oxygen next stainless steel flask here we're going to put it in and potassium chlorate decomposes at about 500 degrees celsius so i'll just go pop this into the furnace and boil off the oxygen nice just hoping it doesn't overreact yeah so this should be potassium chloride it looks to me like it foamed up but didn't boil over so it got kind of lucky there you can see the spots where oxygen bubbles would have been coming out let's uh i might have to dissolve it out with water that's probably better anyway get rid of all the contamination from the stainless steel didn't hold up as well as i thought it would maybe it was all the extra oxygen so it looks like all the potassium perchlorate was converted to chloride which i have in a water solution now let's pop that out of the thing i'm going to place potassium chloride solution in a glass dish and we're going to evaporate the water once again so let's uh transfer it over to this other dish so i can weigh it and see how much i was able to recover there we go put it on the scale that's 35.7 grams it's roughly half the weight of the original perchlorate so i've managed to remove all the oxygen and i'm left with pretty much pure potassium chloride now this is still about half chlorine by weight i'd like to remove that and be left with the pure potassium but before we do that i think it's in the best form right now to measure the radioactivity you can see i've got a geiger counter going over here let's put this on the potash and see if we can pick up any other radiation so the background is about 20 counts per minute let's see if it increases from there i can already hear it clicking more often i'll just speed up the video it takes a minute or two for the counts to come in so yeah it's about double the background radiation when i pull it away you hear it stops clicking so much so the stuff i have here is definitely slightly radioactive that proves that bananas are radioactive let's do the small amount of the potassium 40 isotope of course there's not very much of it so they're not really radioactive enough to worry about to pull the chlorine off the potassium i'm going to use my alkali metal converter which i've shown in another video and i'm going to add eight grams of lithium i should only need like three grams but turns out lithium is very reactive to even nitrogen so it's fairly hard to get a 100 conversion so here's the potassium chloride which will be extracted from the bananas put it in there on top of the lithium there it is we have metallic potassium here is a close-up on the potassium when pure it is a soft silvery white metal which rapidly tarnishes to form a gold color and then with more tarnish a blue color that you see here and eventually it'll end up a grayish white as more oxides build up i for one think it is rather pretty now unfortunately this is only about half the potassium i was expecting uh if i got full conversion on the potassium chloride i should have expected around 18 grams instead of this nine here i have figured out what happened though you see the potassium vapor is supposed to come down this tube condense into a liquid and then drip out into my bottle of mineral oil but the end of the tube got a little bit too cold and some of the potassium solidified once solidified it plugged the tort and the potassium vapor had nowhere to go except out through the liquid tin seal the molten tin absorbed most of the potassium vapor only a little bit of it looks like it burned inside the furnace obviously i need to redesign this a little bit i think this is probably the last time i'll use this particular torque but it did fail safe you know that's exactly what i wanted it to do in the event that this had occurred so speaking of yield losses according to the fda a banana has approximately 360 milligrams of potassium per 100 grams of the fruit and judging by the perchlorate that i managed to extract i had about half that now i don't think my yield to that point was actually 50 percent like the burning it to ash washing it out i can't imagine the losses being more than a few percent you know you've got transfer losses and things but you're not going to lose half of it doing that so i think the banana actually didn't have as much as they said it would and you know fruit can have a wide range of potassium content depending on the conditions it's grown in perhaps the soil that it was grown in was a little bit potassium deficient i'd say that's likely so anyway now it's time for the part of the video you've all been waiting for i have made a tiny banana out of potassium extracted from bananas let's just chuck it into the water and see what happens nice the power of bananas i think potassium is one of my favorite alkali metals it's got a good mix of reactivity and energy density anyway hope you enjoyed i'll see you next time [Music] [Music] you

Channel: Cody'sLab

Views: 2,351,229

Rating: 4.9425702 out of 5

Keywords: Potassium, Banana, bananas, Element, Chemistry, science, alkali metal

Id: fmaZdEq-Xzs

Length: 22min 30sec (1350 seconds)

Published: Sun Dec 20 2020

Reddit Comments

[u/AyatollahDan]

The charcoal was really spicy today

[u/[deleted]]

Wow, that’s a pretty solid yield Cody. I was expecting like just a little bead of potassium.

[u/stevethewanker]

Wow, Cody is looking good these days

[u/idontchooseanid]

This show has finally gone bananas

[u/VirtualMountain]

That was fascinating.

And explosive.

ETA: It would make sense that the potassium yield was lower than expected, since growing bananas would deplete the amount of potassium in the soil and if its not replaced completely between harvests you'd end up with potassium-deficient bananas.

[u/squarecoinman]

Great video , in these covid times being locked up , there is nothing better than Cody and some explosive banana metal . Thank you for putting a smile on my face