#1 Science Forum For Lab Technicians

Hi just been asked for Bromine Water for second period on Monday, and my trusted bible says use ampules which we dont have!!!! Ive never made it and have no idea how please help asap as have about three hours to make it in,

cheers MariaC

There's a real easy method under 'Bromine' in CSIS Appendix F: just add a few drops of H2O2 & H2SO4 to dilute KBr solution.

Add a few crystals of of Potassium bromide in 5mls of 1M H2SO4
Add a few drops of 10 vol H2O2
Adjust accordingly to the volume needed

Thanks all Ive found a recipe and instructions on how to do, will let you know how it goes, panic over for now!!

Cheers Maria

So made it and still alive to tell the tale!!Thanks for the help,

Cheers Maria

For those who refuse to make up bromine water from scratch. (had a bad accident).
Georgia Deretic who co-wrote Foschem Senior Chemistry gave me a substitute that works just as well and less dangerous.

Bromine in Situ
100 mls 2m Sulfuric Acid
50 gms Potassium Bromide
Dissolve
Add drop by drop of Hydrogen Peroxide (100 vol) till deep brown colour.

Ok next question, after making the Bromine water I left all the equipment dismantled in the fume cupboard for a few hours to get rid of the gas. However when I went to clean up more gas appeared from the round botton flask I had produced it in, as I moved it the flask. How am I going to clean this up without gasing myself any ideas gratefully recieved.

Cheers Maria

URGENT NOW
making bromine with ampoule (1ml in tablet form)
what volume does it make
Please help?

Rita

Hi everyone

Panic over! Teacher asked for wrong timeslot. However, I do have the ampoules but not the volume they make up to. Appreciate your help.

Rita

Hi Rita, how much is in the ampule? it should say on it, cheers MariaC

Opps just read 1ml!!!

A 1ml ampoule makes up 200ml of bromine water.
Do you have safety instructions for making up Bromine water from an ampoule?
Check out http://www.practicalchemistry.org>Standard Techniques
If my chemistry teacher requires Bromine water to be made up I show them the Bromine ampoules and tell them that they can make up their own solution. This is one chemical that I won't prepare.
I have a number of these ampoules in stock and would like to know if the bromine in the ampoules has a particular shelf life.
Lyn.

I refuse to prepare this chemical too.
I buy the solution ready made when required, and hang the expense!!
Julie

buy it already made.....its too dangerous to prepare.....its OH&S .........OR.....the teacher prepares the bromine water from the ampule
REMEMBER.........OH&S

Some time back I had a chemistry teacher who really did know his stuff and was pretty competent. He prepared his own bromine water using an ampoule of bromine. I watched from a safe distance as he crushed the ampoule in the water. Neither of us could really remember what happened next but something backfired in the process and there was a cloud of brown smoke and a certain amount of splashback. I backed out the prep room door because of the fumes and he ended up with burns to his arms and some blistering to his neck and face. So even those who know what to do can have mishaps. The gas wouldn't have been good for his lungs either.
The next time bromine water was asked for I gave the chemistry teacher the ampoule of bromine and the instructions and she made it herself without any problems. I don't think I am being unreasonable about not making this chemical solution from the ampoules. I will be glad when the bromine ampoules have been used up and I can use the alternatives which have been suggested in other threads about bromine water.
Lyn.

I have just been asked for this prac too ARGHHHH I have been in 3 schools in a year and have been 'lucky' enough to do it in all 3 of them.

It is the most stinkiest, headache inducing prac...and i am wondering if it really needs to be done? Can't they just watch a video on you tube?
I have to talk to the chem teacher here....i have previously set the prac up in the fume cupboard (so 1 set of everything except test tubes), stduents come to fumer cupboard 2 at a time...but this teacher wants 10 dropper bottles of bromine water...
Will be glad when this prac is over hopefully for a year this time!!!!

No way! Why would they want 10 dropper bottles? Are they going to inflict the fumes on the whole school?
I would absolutely refuse to even make up 10 dropper bottles of bromine water.
My last delivery of the made up solution arrived broken. You could smell it before the box was open. I refused to open it. I'm not usually that hard to get along with, but there are limits, and that crosses the line.
Does this teacher even know what he/she is dealing with?
Julie

from the prac order form it looks like she has ordered 10 sets of everything, so it can be done at the work benches...but as i said i have to talk to her about it when she is off class - and yes, i do not want to prepare 10 dropper bottles...they only use 2 drops per reaction anyway don't they??

I have the prac instructions from my Chem teacher, and they say 20 drops of each chemical.
We only have a small group, they will gather round the fume cupboard while the teacher does the experiment as a dem. (She is very pregnant by the way, so hope she is careful.)
Julie

spoken to the teacher - she is going with the prac at the work benches, but they will open all the windows.

Glad it is the lab furthest away from my prep room.

The bromine water i have is sufficient enough for this prac....so i escape making fresh stuff for this year....next year could be another matter....

Oh well better go do some work...