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Pyro
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how about an out of control P fire involving 1kg P and a near death?
http://www.sciencemadness.org/talk/viewthread.php?tid=23941#...
all above information is intellectual property of Pyro.  |
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bismuthate
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I accidentaly spilled lead acetate on my desk and dissolved my socks in acid last week. Everyone has their moments.
P.S. in another thread you said that there is still phosphoric acid in the air in your lab. How did it last that long?
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Pyro
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The breath stinging stayed around for a week or so. perhaps you mistook it for bromine vapor
How did you dissolve your socks???
all above information is intellectual property of Pyro. |
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bismuthate
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They fell in a nitrating bath. It made NO2 and turned to a green chunky mixture.
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deltaH
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lol bismuthate classic!
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Cou
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Quote: Originally posted by Cheddite Cheese  | | The electrolysis took 12 hours (overnight). The distillation of the bromine from the acidified solution took about 45 minutes. I ampouled the bromine,
but when I was flame sealing the (cheap) ampoule the glass cracked and some spilled on my hand. I was able to save most of the bromine, though, and
the bromine burn I got has healed completely. |
In the video posted above, it took almost 26 hours
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unionised
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Love the sense of priorities. :-)
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MrHomeScientist
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Man my videos are showing up all over SM today. My fame is growing
My electrolysis took 26 hours because that is how the math worked out to produce the optimum ratio of bromide to bromate. You could certainly run for
less time, but you would get accordingly less product. When it must be electrolyzed for so much time regardless, why not run it to completion?
| Quote: | | I remember reading a method that uses electrolysis, sodium bisulfate and sodium dichromate but I can't find it |
With a bare minimum of effort, you can find all that you seek through Google. Typing in words copied from your description, "bromine electrolysis
sodium bisulfate," yields my video on this method as the first hit.
| Quote: | | I'm too lazy to use stochiometry |
This is a terrible way to approach chemistry. There are some hobbies, like cooking, where exact measurements aren't completely necessary, but
chemistry is not one of them. If you do not do your stoichiometry, very bad things can happen. You waste chemicals, lose products,
and can cause dangerous runaways or unexpected side reactions. Having the skill and patience to do the math beforehand is absolutely essential here.
You also must understand how the reaction works before attempting it. What are the possible products? Does it need cooling/heating? Write out the
balanced equation before you do anything, and see if your plan makes sense. Chemistry is a lot of fun and a great hobby, but can literally kill you if
you do not respect it. If you really are "too lazy," put your chemicals away for a few years before you seriously hurt yourself.
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Metacelsus
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I electrolyzed for less time than you did, but at higher current. I calculated the total amount of charge I needed by Faraday's Law of Electrolysis,
so I'm pretty sure I electrolyzed it for long enough.
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MrHomeScientist
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Of course - you can certainly change parameters around and get the same results as long as the math works out. In my comment I meant that if
everything else was kept the same as my setup but run time was reduced, you'd obtain less bromine at the end. It's also detrimental to run it too
long!
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Cou
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| Quote: Originally posted by Cheddite Cheese | | I electrolyzed for less time than you did, but at higher current. I calculated the total amount of charge I needed by Faraday's Law of Electrolysis,
so I'm pretty sure I electrolyzed it for long enough. |
Just made the solution with 100 grams of sodium bromide in 300 ml of water, and half a gram of sodium dichromate. I was going to do this with a 1 amp
power supply for 40 hours, but I can't start because I only got 1 carbon electrode instead of 2 >_<
Also does the amount of electrode exposed to the solution matter? What if I only submerged a tiny amount of electrode, vs the whole thing? If it
doesn't matter, I can just snap the one carbon electrode I have in two pieces, and use those
[Edited on 29-10-2013 by Cou]
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WGTR
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| Quote: Originally posted by Cou | I can just snap the one carbon electrode I have in two pieces, and use those
[Edited on 29-10-2013 by Cou] |
You might want to hold off snapping your precious carbon
electrode in two. The anode material is more important than
the cathode material, and you can probably use something else
for the cathode.
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Metacelsus
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The amount of electrode in contact with the solution does matter. You don't want to be operating at too high of a current density, or else you will
get side reactions, like formation of oxygen, and excessive anode erosion. As for the electrodes, WGTR is right: you should use something else, like
stainless steel, for your cathode. Personally, I used a MMO anode and titanium cathode, but I'm guessing you don't have those.
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Cou
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Well I already snapped my carbon electrode in two >:-( wonder if there is a place i can buy more, because elemental scientific takes forever to
ship
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ParadoxChem126
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For the carbon electrode:
http://www.youtube.com/watch?v=knc1lSupAwQ
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woelen
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Here is a write-up of the NaBr/NaHSO4 method. I have made this write-up a few years ago, with the goal of making bromine a more accessible chemical
for many home chemists.
http://woelen.homescience.net/science/chem/exps/OTC_bromine/...
The hexavalent chromium, needed in the experiment, now also is not a problem anymore. Use some bleach and chromium sulfate or chrome alum (which both
are available on eBay frequently and are not suspected and have no hazmat properties) to make a solution of hexavalent chromium, which can be added to
the concentrated solution of NaBr as is, without the need to isolate the hexavalent chromium.
[Edited on 29-10-13 by woelen]
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Cou
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| Quote: Originally posted by woelen | Here is a write-up of the NaBr/NaHSO4 method. I have made this write-up a few years ago, with the goal of making bromine a more accessible chemical
for many home chemists.
http://woelen.homescience.net/science/chem/exps/OTC_bromine/...
The hexavalent chromium, needed in the experiment, now also is not a problem anymore. Use some bleach and chromium sulfate or chrome alum (which both
are available on eBay frequently and are not suspected and have no hazmat properties) to make a solution of hexavalent chromium, which can be added to
the concentrated solution of NaBr as is, without the need to isolate the hexavalent chromium.
[Edited on 29-10-13 by woelen] |
YES, that's the website I was looking for. Just curious, what happens to the hexavalent chromium after you get the bromine? And in the part where the
bromine pools in the bottom, what is all the foamy stuff above it?
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woelen
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The hexavalent chromium simply remains in the aqueous layer. It might be that some of it is converted to trivalent chromium. It only plays a role
during the electrolysis, it largely prevents the back-reduction of bromate to bromide.
The 'foamy stuff' above the bromine is not really foam. It is an aqueous layer. It looks foamy, due to small bubbles of air, sticking to the glass
under the liquid, combined with the very bright light of the flash unit from my camera. The lighting of that picture is sub-optimal, it could have
been better.
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