Preparation of Bromine

[@TheNrp8598]

Hey doug you need to make a video that will go viral so people will finally find you. You make great quality content and don't get the recognition you deserve

[@DougsLab]

TheNrp8598 Hey, thanks! :)

[@morningstarsci]

Doug's Lab Yes, Doug, you do produce very good quality and informative videos. There are already videos on KZbin regarding SO3, so all that is left is SCl2, and then thionyl chloride. To be honest, I would rather purchase it, but it would be nice to see a demonstration of its preparation. I also don't fancy working with SO3, in particular.

[@stefano9939]

Doug's Lab where are youuuuuuuuuuu, please come back

[@jhyland87]

@@stefano9939 He seems to have disappeared :-(

[@1495978707]

Problem is that any chemistry KZbinr that gets big starts getting harassed a lot more by KZbin and such

[@AddisonPhilips]

your continuing respiration is a good testament to your fume hood arrangement :-)

[@JohnDoe-qm5uo]

Even though you froze it, I'm amazed that you managed to store your bromine in a bottle with a PP or PE seal. I've always needed to use the VWR bottles with a Teflon lined cap and Teflon tape around the seals or the bromine escapes and starts oxidizing everything in the near vicinity. Do you have any issues with this?

[@SciDOCMBC]

Even frozen, bromine will escape from any vented container (even if sealed and secured with PTFE). To store elemental bromine safely, it must be sealed in glass ampoules.

[@Ambient_Scenes]

Awesome! My favourite chemistry channel on YT!

[@RaExpIn]

I've prepared some bromine at a small scale a few weeks ago with sulfuric acid, manganese dioxide and sodium bromide. It's such a fascinating element! Btw I really like your channel! You definitely need more subscribers...

[@xxilluminatixxxx]

+Random Experiments International Don't drink it tho xD

[@RaExpIn]

Too late... XD

[@promet247]

Basically, a well made video. A couple things--in your equation diagram you used KBr, but in your demonstration you mentioned adding NaBr--so which one, and also no mention of the quantity of whichever bromide you used. Also it seems like you used an excess of H2O2 based on the KBr equations --am I wrong about this? Thanks for making the video.

[@PauloConstantino167]

I've never seen anyone handling bromine as uncarefully as you have done here. Brilliant video though

[@vaclavpflegr4894]

Very elegant way. Nice.

[@ScienceMarshall]

Great video! Very informative and engaging. I love synthesizing bromine. It is one of my favorite reactions for sure. I've made a video on it too, but I used a few different chemicals.

[@Metalhammer1993]

dumb question, but shouldn´t you be able to directly oxidize the bromide ion in the potassium bromide or am i missing out on something? i would anticipate KOH with some sideproducts depending on how the H2O2 reacts. if it acts as a radical starter as it does when reacting H2O2 with Fe(II) things get funny but i still ould think i get KOH and some HBrO which immediately should react with bromide in the solution to bromine as well, right?

[@ckimsey77]

PLEASE READ>>>>>> I know H2SO4 is a decent oxidizer on its own, but the main oxidation rxn is driven by the strong ox. peroxide...so why cant you directly oxidize the free Br- ions in solution with peroxide and skip the sulfuric?? It should work the same, though i have not yet sat down and worked out the details of rxn mechanism (I plan to make Br2 soon for a synthesis of bromoacetone to prep it for C-C bond formation). Is the acid needed as a catalyst to get the peroxide to activate more easily? If it acts as catalyst, couldnt u use much less? Unless the presence of H+ ion somehow aids peroxide by forming a more potent oxidizing intermediate, which it may, i dont see the difference of free Br- in solution not reacting w peroxide vs free Br- in acidic solution being oxidized. Have u tried w/o sulfuric? Also, doesnt peroxide react and break down into O2 gas and water in presence of H+?? The proton attaches a lone pair of O in h2o2, creating + charged leaving group water radical (most all peroxide mechasms is O-O bond radical cleavage ). This radical hits another h2o2 and the O of water radical pulls electron from one side releasing the H as an ion and forming neutral water. Now the O that lost electron and H shifts from sp3 hybridization to sp2 b/c of lone pair electron repulsion, promoting the single e- into empth p orbital. Do all this again with the other half, and when 2nd water is formed the leftover O-O bonds a second pi bond through p orbital generating O2.... In total, h2o2 + h2o2 + 2H+ yields 2 H2O + O2 + 2 H+ (catalyst regenerated). This is correct mechanism im quite sure, do u agree? ( peroxides can do other radical mechanisms but still same end result w trace other products w other species present). It also self degrades slowly into O2 and water by similar mechanism, h2o2 splits as two hydroxyl radicals, which attack another h2o2 in same fashion; this is much slower though So in theory, the radical can attack Br- ion as well, stripping an e- as so: h2o2 >> 2 HO. radicals 2 HO. + 2 Br- >> 2 OH- + Br2 Geez, i just answered my own question working out this mechanism...If no acid were present, hydroxide ions would build up and high pH they would begin to react w product into multiple species...back to ion as well as BrOH and other strange bromine oxides. Well, being a chemist too, do you think my logic here is correct? If so maybe an acid easier to get than 98% sulfuric could work too; possibly starting with addition of h2o2 to br- solution to start rxn and prevent peroxide being wasted in side rxn w acid breaking itself down. Then once started, drop in acid at a rate to keep pH slightly acidic. What are your thoughts? I will definitely play with this when i make my Br2 and try to fully solve the problem and test for more optimal way and/or method to use less chemicals etc. If you by some miracle actually see/read this, let me know if ur curious and ill share my results with ya. Great video man. Why i love chemistry: even this simple redox rxn is actually way more complex than most would think if you go deeper into understanding the "how and why" of this reaction. To those of you non-chemists, seeing a taste of figuring out mechanisms to get desired product, proper pH, not showing calculations and other work needed to get a successful run....try doing an 8 step organic synthesis where each step requires all this plus much more; and one mistake at step 7 after a week of work and its back to beginning!! I love chemistry b/c its a great challenge

[@firstboy5479]

write for my viber [phone]

[@Alexjaeger1024]

I see you used a dimroth (might be friedrich, couldn't tell) condenser for the Br preparation. Could a less efficient condenser like a graham condenser still be used? Or would there be too much product loss? Thanks Doug, I love your videos

[@skyym3629]

Cool video bro. Thanks for the demonstration. Have you seen how some of the other chemists on KZbin store there bromine in vials that they seal themselves with a propane torch? That way, I guess you can store it at room temp without worrying about loss of product. Cheers

[@gold.keng1]

شكرآلك انت شخص رائع وتستحق ان ارفع لك قبعتي

[@helddermolekule5503]

A little bit of calculation would be nice, how is your yield?

[@Ambient_Scenes]

I would also attach a hose to the prong above the collection flask that leads into a vitamin C solution. That way any Br2 fumes that evolve out of the collection flask will bubble through the vitamin C solution and will be reduced to harmless bromide. (Vitamin C reduces elemental bromine) Also, if you're adding hydrogen peroxide to sulphuric acid, won't you run the risk of making piranha solution???

[@alexslab.4875]

No, piranha wont form, as the acid was diluted previously with water. Piranha only forms with concentrated sulfuric , not dilute

[@Angrychemist666-g4x]

Really Doug???😮 you're going to put the most evil, Mr. Catch me if you can, perfect escape artist in a 4 for 50 cents Boston bottle 😂😂😂😂😂😅😅

[@beanlets]

I have hbr acid . but what about 29 % h2o2?

[@Prchemist06]

You can also use NaOH to neutralise Br

[@Angrychemist666-g4x]

I'm starting a go fund me page so we can get Doug a few pyrex media storage bottles with the PVC coating, for added protection! This is what happens when you watch Indian chemistry videos, I'm glad he's not far gone to the point where he uses a used Sprite soda 2liter bottle!😢😢😢😢

[@3er24t4g1]

There are a lot of great oxidizers to use in this reaction. Almost any reaction will work. I have no ampules so I only store bromine water. For my bromine genesis I use calcium hypochlorite. Speaking of acids I am trying to easily make 70% HNO3 using calcium nitrate from amazon and sulfuric acid. My greatest challenge is filtration maybe I will let the Ca(SO4)2 settle and then simple decant. Any way I just have not have and good yields recently in HNO3 experimentation.

[@DougsLab]

JMAPScience I have a nitric acid video planned for the near future. Do you have the ability to distill?

[@bludeat7398]

nicee video!

[@Angrychemist666]

Couldnt i just use a regular distillation apparatus?

[@guntotinmedic]

dude, are you the same Doug that used to post on association of backyard metalcasters?

[@baptisteboissiere]

Hello Doug's Lab, how many grams of potassium bromide did you use ?

[@baptisteboissiere]

+Doug's Lab ??????

[@UltrafunkAmsterdam]

200 grams

[@amosz5726]

What's your source for hydrogen peroxide? And also, do you know if 3% hydrogen peroxide will be enough to oxidize the HBr if used in sufficient quantity? It worked just fine for producing elemental iodine but I think bromide is less prone to oxidation than iodide.

[@DougsLab]

Amos Zoeller I get mine at the local hydroponics shop.They sell it as 29%. The hair care aisle at the grocery store sells 12% for bleaching hair. 3% might be problematic because bromine is slightly soluble in water. With a boiling vessel large enough, you can probably still coax the bromine out, but your batch runs are going to be very small.

[@amosz5726]

Interesting, I'll do some searching at my hydroponics store. Also, why aren't you ever on skype anymore :(

[@davyzeng6232]

Amos Zoeller Also, you can heat 3% hydrogen peroxide and evaporate the water until it reaches ~30% concentration. Also it is SUPER IMPORTANT to add the hydrogen peroxide slowly. When I was adding mine the ground glass stopper of the addition funnel fell out and ALL of the H2O2 entered the reaction flask. Super violent boiling with huge plumes of bromine everywhere.

[@amosz5726]

Davy Zeng Well hi there, Davy. Yeah, I was aware of concentrating hydrogen peroxide that way, but I haven't really thought to do it myself, yet. Maybe I'll prepare some and store it for these kinds of things.

[@AddisonPhilips]

Davy Zeng you can also purify the hydrogen peroxide by way of fractional crystallization (in other words, chuck it in the freezer)

[@xxilluminatixxxx]

What is Bromine used for? I mean,what kind of uses doe's it have to offer? I mean,it's toxic and all-so i don't really see a mainstream use for it,i guess it's use to make some compound's and other chemicals.Anyways-great video!

[@xxilluminatixxxx]

+Maanuve Also, how toxic is it? You said it's fumes are just as toxic as chlorine,and i've used and worked with chlorine before and had to real danger with it.Tho i did take precautions wen handling it.

[@trevorsquires6976]

+Maanuve Bromine is used for the brominating of some compounds, especially organic compounds. Some bromine-containing, organic molecules are flame resistant and are used in children's clothing to protect kids from catching fire by their clothes.

[@petrolak]

+Maanuve you need halogenated carbohydrates for Friedel-Crafts and Grignard reactions, which are some of the most common reactions for organic synthesis using chlorine (let alone fluorine) for it is problematic and iodine isn't reactive enough so it kinda leaves you to use bromine

[@bellacullen1228]

I love chemistry

[@Bigwingrider1800]

LIKE A MAD SCIENTIST BROTHER. COME ACROSS THE CHANNEL WITH THE FURNACE. STILL COOL CHANNEL..

[@nikoskaravitakis9437]

what do you believe is the best method to make fluorine .i ve seen on wikipedia that copper difluoride will decompose to copper and fluorine at high temperatures . electrolysis of khf2 seems appealing.also will electrolysis of molten fluoride salt like potassium fluoride work ?

[@MuzikBike]

Fluorine is super reactive. If you store it with a noble gas, it will probably react with the noble gas. The only ways to store it make it so you can't see it. Not to mention it eats glass. That said, I want to see a synthesis of it even more badly.

[@Druicidal]

Otc, decomposition of fluorite (CaF) with oleum.

[@ColinRies]

ehm, that would yield HF, not elemental fluorine.

[@Druicidal]

Colin Ries whoops. KOH+HF yields KF, which can be electrolyzed to potassium and fluorine though, assuming my memory hasn't crapped out again.

[@ColinRies]

Andrew Metzger that could be possible (like chlorine can be made my electrolysis of NaCl), but it's not very practical since you need to do it in molten state and working at these temperatures with fluorine is probably anything but a good idea. I actually have no idea how to make fluorine at a lab scale, but I think it wouldn't be wise making it anyway.

[@derekwashuck7691]

When you make elemental bromine or iodine or chlorine or fluorine what do you use to clean you glassware ?

[@196Stefan2]

@Benjamin Joshua Beggs No one would be able to make fluorine with this set-up. Fluorine can only (almost *) be prepared elektrochemically by elcetrolysis of a KHF2/H2F2-mixture (* there's a way to reduce CoF3 to CoF2, but cobalt(III)-fluoride isn't accessible to mortals).

[@196Stefan2]

@Benjamin Joshua Beggs Not really. I think a reason why a KHF2/H2F2-mixture is preffered, is the relatively low melting point of this mixture compared to NaF (993 °C). Further details: en.wikipedia.org/wiki/Fluorine (s. "isolation")

[@gold.keng1]

شكرآلك❤

[@ronnieboomboom2040]

And what are you doing with bromine?

[@ThePeterDislikeShow]

Does it work with chlorine, H2O2 + 2HCl -> 2H2O + Cl2 ? I can swear I've used mixtures of HCl and peroxide to clean and I've never seen chlorine form.

[@synthol9635]

Yes, but to some very low extent , becouse Cl2 in presence of water goes back to HCl

[@ThePeterDislikeShow]

@@Paonporteur I could swear aqua regia gives off chlorine! You need pretty good ventilation to use it.

[@cannagorilla]

hey Doug, can I use sodium bromide that is powder and is 99% NaBr

[@alexslab.4875]

yes

[@阳阳-c4v]

How much? NaBr

[@DoRC]

Can you synthesize some wd40 for that jack?:)

[@bitterlemonboy]

Nobody exactly knows what wd 40 is made of, its a trade secret

[@geeder9086]

@@bitterlemonboy I hear it's derived from fish oil

[@arjunyg4655]

Those nitrile gloves aren't gonna do anything against that bromine lol...they'll last about as long as tissue paper in a bonfire...

[@geeder9086]

You need a little graphite powder for the lab jack

[@darealjoff19]

So, how much Sodium Bromide was added? If it's a 2M solution (1M=102.894/L) and 170ml solvent, would it be ~35g NaBr? This is from VERY rough calculations in a coffee shop, but it sounds right... unless I'm missing something.

[@mr.suphathin1638]

How many percentage is its concentation

[@dpchannel8442]

do you know how to change the color of metal mercury(not losing its liquid state) or gallium

[@chemiosmoticphosphorylatio3198]

Not possible

[@edwindudoussat1279]

Doug in the beginning of the video you gave the equation using potassium bromine. But later in the video while performing the reaction you said that you where using sodium bromine. So which one did you use?

[@mduckernz]

+Hillebrand1 So long as you adjust the relative masses/molecular weight, that is. Though this should be obvious

[@AnnaBerlin4008]

🧡

[@hariadarichemical]

thanks

[@gabrielmotoc1234]

How many grams of sodium bromide did he add ?

[@UltrafunkAmsterdam]

200 grams

[@sleepychemist2701]

I would've quenched everything with dithionite or thiosulfate instead of letting everything escape.

[@tommasopetrella4856]

My Bromine salt is only 25% sodium bromide, can I still use it in this synth?

[@tommasopetrella4856]

not yet.

[@xuNsh1ne]

Tommaso Petrella thats good :) be careful - bromine is something you don't want to have at home...

[@MrItsthething]

I got bromine on my hand, and it didn't burn. Nice video.

[@rageblanket2139]

MrItsthething the bromine you got on your hand was fake and gay and obviously photoshopped! IMPOSSIBRUUUUUUUUUUUUUUUUUUUUU

[@xxilluminatixxxx]

+MrItsthething Really?

[@rageblanket2139]

Maanuve Yep. That's what is said on KZbin if you're disagreeing and you're full of shit. " fake and gay and obviously photoshopped"

[@xxilluminatixxxx]

Rage Blanket Lol,the word "gay" isn't even an insult.These is the Internet i guess.

[@rageblanket2139]

Maanuve your opinion on the word gay is fake and gay and obviously photoshopped

[@Bigcubefan]

Why does every glass surface that gets touched by bromine stay a redish/brown color even after the liquid bromine is gone? That's been bothering me eversince highschool.

[@joshl1350]

I think it's from the bromine fumes

[@Bigcubefan]

Josh Lukowicz Even if you empty them and clean them, the glass stays brown. :(

[@joshl1350]

+Bigcubefan it shouldnt

[@Bigcubefan]

Josh Lukowicz That doesn't really help, you know.

[@joshl1350]

+Bigcubefan well if the bromine vapors are gone the glass shouldn't still be reddish brown

[@annelieseocallaghan801]

In the introduction, why is he putting copper sulphate in a Buchner flask?

[@alexslab.4875]

it does not matter too much, its just for a intro

[@isbestlizard]

i think I prefer chemistry to cooking

[@festerwalter]

D-lsd-25

[@ckimsey77]

I trying to start channel, but not far in my camera broke and cant afford another yet.._I first was doing in depth how to extracting DMT from bark, explaining how it works not just providing instructions like everyone else, and why skipping simple steps like defatting is devastating to your yields and purity etc. Check it out if u get bored, being a chemist u may like it. Ive a MS in chemical engineering w minor in biochemistry and polymers; done several years of R&D so im pretty complete on knowing processes generally

[@MichaelSmith-hh6ox]

Does 29% have to be used, or could less concentrated, but higher volume H2O2 be used?

[@alexslab.4875]

nah probably use greater than 25 or use kmno4 or mno2

[@williammekhjian354]

was this before or after ya robbed me with 321 and all those hobos.

[@thomasfink2385]

The intro is too long