Sciencemadness Discussion Board

Bromine (?) + saturated copper sulfate solution

mattrod9523 - 23-10-2008 at 19:22

I am doing an experiment of heating potassium bromide and capturing the gas in saturated copper sulfate solution. I know that potassium bromide emits potassium oxide and bromine gas when heated. There's two things. I don't know if the potassium oxide is gas or solid. The MSDS sheets I saw indicatied a solid. Anyway, if the bromine was the only vapor, and it entered saturated copper sulfate solution, what would it produce. And also, what is the chemical formula for saturated copper sulfate solution, because the MSDS sheets said not applicable. ??????????????????

mattrod9523 - 23-10-2008 at 19:25

Anybody?

smuv - 23-10-2008 at 19:32

Why did you wait 3 minutes and then ask 'Anybody' as if 3 minutes is too long of a time to wait for a response.

I vote to have this thread moved to beginnings or detritus, because stuff like this is unacceptable.

Matt, before I compose a response to the question, what do you expect to happen? What is the point of doing this experiment if you have no hypothesis what the outcome will be?

12AX7 - 23-10-2008 at 19:36

Seems to me, KBr melts.

If you got your information from an MSDS, let it be known that they are generally inaccurate.

Tim

mattrod9523 - 23-10-2008 at 19:57

First of all, I put down "anybody" not as an impatient persistance, but as an extra note to ask for opinons and ideas. Second, I do have a hypothesis, just wanted to know what everyone else thought themselves. I hypothesize that potassium oxide, due to its poorly known or identified gas state of matter, would be in a solid state during the experiment. The bromine vapors formulated would enter the saturated copper sulfate solution to form some sort of copper bromide component. That's the part that I posted for. The entering of bromine gas (Br2) in saturated copper sulfate solution, whose formula I am not completely assured of. I estimate that its just CuSO4 * H2O compound, because of its blue color. Well anyway, those are my questions.:D;)

[Edited on 23-10-2008 by mattrod9523]

mattrod9523 - 23-10-2008 at 20:00

If it melted, I do believe it would then boil to give off vapor.

mattrod9523 - 23-10-2008 at 20:08

Also, what I meant was that potassium oxide appears to be solid in most MSDS's. It could also be liquid.

kclo4 - 23-10-2008 at 21:12

Do more research and make sure you know what your doing, and what is going on.
Even a simple wikipedia search would be tons of help to you.

For example: http://en.wikipedia.org/wiki/Potassium_oxide

Potassium Oxide isn't going to form!
IFF the potassium Bromide is oxidized, it would produce Potassium Peroxide.
K2O2 is very very dangerous!

You seriously do not want to be mixing, heating, and doing whatever with different chemicals if you do not have a good Idea as to what is going to happen. Many toxic chemicals, unstable mixtures, etc can be produced easily.

An example is one time I didn't fully understand what Hydrogen Sulfide was.
I knew it was rotten egg gas, and that was enough to start the experimenting for me back then - I didn't bother to read anything much more then that and how it can be produced.

I reduced Calcium Sulfate with carbon, and then added Acid - The first time it seemed to work great, very stinky stuff, so I thought I would do it again, It produced bubbles, but I could not smell it - so? I did it again, still.. no smell of H2S, but it still produced bubbles.

Guess what happens when you get into the toxic level of Hydrogen sulfide? You lose the ability to smell it!
.. so, this was very stupid of me, but it just goes to show you how screwing around with chemicals can get you into a lot of trouble. So please, make sure you know what you are doing, and its probably best/safest if you actually have an experiment instead of just some "i dunno i'll just do it" type of stuff. The Experiment should be with a hypothesis, you should understand the reaction, the dangers of the chemicals, etc.

Edit: Also, Does Br2 form a complex with Copper Sulfate?

" And also, what is the chemical formula for saturated copper sulfate solution, because the MSDS sheets said not applicable. ??????????????????"

What do you use to make a Copper sulfate solution? (Water and Copper sulfate)
Do they react if it is a Copper sulfate solution?
... No!

Do mixtures/solutions have chemical formulas?
http://en.wikipedia.org/wiki/Chemical_formula

That should help you.

Also, 20 question marks doesn't make your question a better question, answered faster, or make it more important. If anything, It causes someone to rant :P

but hey, your knew around here, but you probably want to do some lurking to figure out how the SMDB people like it so you can post with out irritating them and what not, you know what I mean?



[Edited on 23-10-2008 by kclo4]

not_important - 24-10-2008 at 00:28

You can edit your own posts for short period of time, which is much better than posting multiple times.

A quick look at wikepedia would show KBr has both a melting and boiling point listed. This generally means that a compound is stable within that temperature range.

Alkali metal halides are generally pretty stable, iodides being the least and still reasonable stable if oxygen is kept away. It may be possible to form some potassium oxides in a fire, but that's not really a preparative process. As further evidence, older processes for preparing KBr, often as part of a bromine extraction or recovery, was to absorb the Br2 in KOH or K2CO3 solution, then evaporating to dryness and decompose the KBrO3 in the mixed salt by heating to dull redness; the KBrO3 decomposing to oxygen and KBr.

A MSDS should be considered a worst case warning, particularly in decomposition products. Think of it as a speed limit; on a dry sunny day and driving a flat straight road you likely can speed without much chance of harm befalling you, do the same on a rainy night driving a winding mountain road ... The MSDS is a guideline and legal escape hatch, if you know what you are doing you'll understand when you need to be concerned with the MSDS warnings.

woelen - 24-10-2008 at 09:19

Potassium bromide does not give off potassium oxide when heated! There is not even oxygen in potassium bromide, so where would the oxygen come from? From the air? IF any potassium oxide is formed in this way, then it only will be a minor constituent of the products. As mentioned above, potassium bromide is very stable and does not easily decompose by heating.

KBr instead melts and if sufficiently hot, it may even boil, but leading vapor of this through a solution of copper sulfate is not going to happen.

If you are after bromine, then you need to add a suitable oxidizer to an acidified solution of KBr in water. By means of heating, you can easily drive off the bromine and lead the bubbles of gas-mix through clean water to make bromine water.

mattrod9523 - 24-10-2008 at 15:37

Oh crap. My stupid brother logged in as me again! Sorry about the uneccesary inconvenience everyone. He's not exactly very catious or serious about the crazy things he does with his chemistry set. Hey bro, if you are seeing this right now, listen; JUST MAKE AN ACCOUNT! It's free! It's no sweat. JUST DO IT!!!

[Edited on 24-10-2008 by mattrod9523]

kclo4 - 24-10-2008 at 15:48

That post reminded me of Occam's Razor. :P

mattrod9523 - 24-10-2008 at 16:07

Excuse me? What's that supposed to mean?

kclo4 - 24-10-2008 at 16:44

Quote:
Originally posted by mattrod9523
Oh crap. My stupid brother logged in as me again! Sorry about the uneccesary inconvenience everyone. He's not exactly very catious or serious about the crazy things he does with his chemistry set. Hey bro, if you are seeing this right now, listen; JUST MAKE AN ACCOUNT! It's free! It's no sweat. JUST DO IT!!!

[Edited on 24-10-2008 by mattrod9523]



well, I'm just not convinced that it was your brother. If he has done it before, as stated in your post, why would you just not change your password or made precautions so he couldn't get on again, such as log out each time? Plus, how would he have gotten your password in the first place?
Also, if you knew he had logged on before, you would have probably told him not to correct? Seems like it would take quite the person to disregard a simple and logical request like that.

Also the way you have posted in this forum isn't significantly different then your other posts. - unless he has also posted those?

Now, I'm not an expert at that or determining who's at the other end of the line but it just seems like there is a simpler explanation.

Anyways, it doesn't matter we really were just giving you some tips, no biggy.
I won't argue about this subject anymore since trolling is a naughty.

[Edited on 24-10-2008 by kclo4]

Silverado7 - 24-10-2008 at 20:40

I don't buy it. I've looked at your ammonium + sodium hydrogen sulphate page. It's not a surprise that this thread's subject is so random like the last one. It's no biggy, though. Even if what you are saying is the truth, I don't think it is the proper subject for a chemistry discussion board. Let's just reboot this thread and start fresh, OK? there is no use in wasting an already started topic.

OK, although you were wrong, Matt, about the potassium bromide giving off bromine and potassium oxide, the thread is about bromine entering copper sulfate solution. So for your experiment, you should heat an oxidized, acidified solution of potassium bromide in water. That will produce bromine vapor (which is irritating and toxic and causes burns, and isn't something you should be uncatiously playing around with!!!). If this bromine enters copper sulfate solution, which may I point out that even though it is saturated it is still mostly water, it will probably part bromine water and part copper sulfate. But I'm no expert at that type of stuff. You can also condense the vapor to form a small amount of bromine liquid ( still dangerous!), or you can capture the gas in water to form bromine water. JUST BE CAREFUL. Make sure you have proper protection and storage for the bromine water or pure element. Take a look at a trusted MSDS for bromine element. If you can't match the percautions, don't do it. Chemistry is a very serious practice.

kclo4 seems like a very wise person for this. Trust me, you'll thank him/her.

[Edited on 24-10-2008 by Silverado7]

Silverado7 - 24-10-2008 at 20:48

Still, this is an amatuer experimenting discussion board. No hard feelings though, Matt.