> chemistry > halogènes > dibrome > preparation-of-bromine-doug-s-lab

Preparation of Bromine

Doug's Lab - 2015-05-08

In this video, I prepare bromine from a bromide salt, an acid, and an oxidizer.

3 - 2018-08-11

without glassware,chemistry would be just half the fun

TheNrp8598 - 2015-05-10

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

Doug's Lab - 2015-05-12

@TheNrp8598 Hey, thanks! :)

Jeffrey Schultz - 2015-07-10

@Doug's Lab Yes, Doug, you do produce very good quality and informative videos. There are already videos on YouTube 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.

Stefano - 2018-05-10

Doug's Lab where are youuuuuuuuuuu, please come back

AddisonPhilips - 2015-06-28

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

John Doe - 2015-05-26

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?

Charles Kogan - 2017-06-09

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

Do RC - 2016-09-21

Can you synthesize some wd40 for that jack?:)

∆pertureChromaKey - 2019-10-20

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

Bella Cullen - 2015-12-09

I love chemistry

Science Marshal - 2015-05-08

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.

Random Experiments Int. - Experiments and syntheses - 2015-07-31

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...

Maanuve - 2016-01-03

+Random Experiments International Don't drink it tho xD

Random Experiments Int. - Experiments and syntheses - 2016-01-03

Too late... XD

skyym3 - 2016-10-17

Cool video bro. Thanks for the demonstration. Have you seen how some of the other chemists on YouTube 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

Blu Deat - 2015-05-08

nicee video!

Ronnie BoomBoom - 2017-07-19

And what are you doing with bromine?

ali imran - 2015-11-25

in the reaction you are mentioning Kbr and then while performing practically you said sodium bromate

IP Trainers & Associates - 2020-07-05

He said sodium bromide you’re saying he said sodium bromate

Paolo Suating - 2019-04-28

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

Václav Pflégr - 2016-08-02

Very elegant way. Nice.

buknolan - 2015-09-12

Yikes I hope you were wearing a suitable respirator for that drying step.

Joshua Hunt - 2019-06-05

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

arjunyg - 2016-09-07

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

hariadari chemical1996 - 2018-01-22

thanks

guntotinmedic - 2017-08-25

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

Doug Mapper - 2017-08-26

You bet.

http://www.freewebs.com/doug-admin/

Carl Groat - 2019-07-27

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.

MrItsthething - 2015-05-08

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

Nice video.

Maanuve - 2016-01-03

+MrItsthething Really?

Rage Blanket - 2016-01-03

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

Maanuve - 2016-01-03

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

Rage Blanket - 2016-01-03

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

Maanuve - 2016-01-03

@Rage Blanket Lol xD

FortNikitaBullion - 2020-03-24

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.

Synthol - 2020-06-24

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

Baptiste Boissière - 2015-06-10

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

Baptiste Boissière - 2015-06-22

+Doug's Lab ??????

Held der Moleküle - 2018-10-15

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

Kim Kuy - 2018-12-29

How many percentage is its concentation

Derek Washuck - 2018-11-22

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

Benjamin Joshua Beggs - 2019-04-01

NEVER MAKE FLUORINE. Also, he wouldn't need to clean his glassware after fluorine because the fluorine would set his glassware on fire. For the other ones water or KI dissolved in water will clean them.

196Stefan2 - 2019-12-18

@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).

Benjamin Joshua Beggs - 2019-12-19

@196Stefan2 Yknow I am now questioning why I ever made that comment. He never actually said he was gonna make fluorine, and it should've been obvious that his setup could not make fluorine.


On a side note, could you not make fluorine by electrolyzing molten NaF (or any fluorine salt, for that matter)?

196Stefan2 - 2019-12-19

@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: https://en.wikipedia.org/wiki/Fluorine (s. "isolation")

Paulo Constantino - 2015-09-24

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

ScienceWithJames - 2017-11-22

Can HCl be used instead of H2SO4?

christianvn1 - 2018-04-06

ScienceWithJames Yes, but it might generate small amounts of chlorine from a side-reaction. Also, HCl is quite volatile so some might be carried over along with the bromine.

Colin Ries - 2018-05-16

actually I'm not sure if HCl is even strong enough to make HBr from the bromide salt.

christianvn1 - 2018-05-17

Colin Ries When looking purely at pKa values, neither HCl or sulfuric acid are stronger than HBr. But what's important is that these strong acids complete dissociate in water, so pKa values are less meaningful. As long as bromide ions and hydronium ions are present in solution, the hydrogen peroxide can perform its oxidizing job in making bromine.

Colin Ries - 2018-05-17

christianvn1 oh OK that makes sense, always good to learn something new :)

Tommaso Petrella - 2015-08-20

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

Tommaso Petrella - 2015-11-18

not yet.

xuNsh1ne - 2015-11-18

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

Bigwingrider1800 - 2017-11-09

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

Lizard King - 2020-06-28

i think I prefer chemistry to cooking

阳阳 - 2019-12-26

How much? NaBr

cannagorilla - 2017-03-08

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

Benjamin Joshua Beggs - 2019-04-01

yes

Occy - 2018-10-18

How did you set up your fume hood? I kinda want to make some dangerous crap, and i dont have any ventilation. Pls respond!

Vivi mannequin - 2019-02-24

The Slimy Crew just do it outside

vanlal Dinpuia - 2016-08-13

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

Chemiosmotic Phosphorylation - 2016-11-27

Not possible

Maanuve - 2016-01-03

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!

Maanuve - 2016-01-03

+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.

Trevor Squires - 2016-03-20

+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.

I don't know - 2016-05-16

+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

Anneliese o'callaghan - 2017-02-24

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

Amos Z - 2015-05-11

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.

Davy Zeng - 2015-06-05

@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.

Amos Z - 2015-06-05

@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 - 2015-06-28

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

Amos Z - 2015-06-28

@AddisonPhilips Have you ever tried this? I'm 90% sure that it will not work.

AddisonPhilips - 2015-06-28

@Amos Zoeller Absolutely, I've got some in the freezer right now. Once it rocks up solid, you just take the cap off, and jam a bunch of holes down through the solid ice (it won't be that hard, because the hydrogen peroxide doesn't freeze) with an ice pick type of tool. Make several long thin holes down through the block radiating out from the neck of the peroxide bottle (like the framework of a teepee) and then, while it's still cold tip the bottle upside down and collect the liquid that drains out through the holes. I'm not sure how pure it is – but it's way more than 3%. Try it, it works :-)

Anon - 2015-05-10

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.

Doug's Lab - 2015-05-12

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

Metalhammer1993 - 2016-11-24

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?

Edwin Dudoussat - 2016-05-29

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?

SinisterMinister - 2016-08-06

doesn't matter

Matt D - 2016-08-24

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

SinisterMinister - 2016-08-24

well yeah, of course

King Game - 2016-03-23

why is Bromine so dangerous, shouldnt it be relatively inert in its molecular form?

Zach Z - 2016-04-04

+Brian P (Браян П) It is similar to chlorine as it is a halogen.

A H - 2016-05-12

Actually it should be the opposite of inert. It has 7 valence e- so it's very reactive

Bigcubefan - 2016-03-24

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.

Bigcubefan - 2016-05-12

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

A H - 2016-05-12

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

The Jeffrey 27 - 2016-05-21

+Bigcubefan rut may have made silicon bromide, I don't think so tho. Only thing I can think of.

Colin Ries - 2018-05-16

I have made bromine and I kept it in a glass bottle for about half a year. I have then gotten rid of it because I didn't need it anymore. The glass was perfectly clear like new. I find it hard to believe that your glass stayed brown. Maybe it was bad quality glass and something in it reacted with the bromine. None of my borosilicate glassware got tinted even in the slightest.

Colin Ries - 2018-05-16

silicon bromide should react with water and it is colorless, just like silicon chloride. But anyways, silicon dioxide is really inert and certainly does not react with bromine.

nikos karavitakis - 2016-08-03

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 ?

Andrew Metzger - 2018-04-07

Otc, decomposition of fluorite (CaF) with oleum.

Colin Ries - 2018-05-16

ehm, that would yield HF, not elemental fluorine.

Andrew Metzger - 2018-05-16

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

Colin Ries - 2018-05-16

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.

Colin Ries - 2018-05-17

Andrew Metzger oh just found out that KF*2HF melts at 70C and the electrolysis is done at 70-130C. That's pretty reasonable. Lab scale production is possible though, with potassium permanganate, HF, KF, H2O2 and SbF5 lol

Michael Smith - 2019-07-12

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

Jonathan X - 2017-10-07

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.