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j_sum1
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Quote: Originally posted by The Chemistry Kingdom  | Is it possible to obtain hydrogen peroxide from sodium persulfate
If you know the answer please reply I am cuurently looking at alternative methods for obtaining hydrogen peroxide because it is a bit costly
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I was wondering about this a couple of days ago. I hadn't gotten to looking it up though.
If there is an answer, I would love to know it.
In answer to my own question. Arrowroot is a good soluble starch.
Ingredients: Tapioca Flour
Contains sulfites
I managed to get half a teaspoon to dissolve in less than 100mL of water. It is slightly cloudy but no sediment has formed overnight.
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Texium
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6-1-2016 at 16:55 |
The Volatile Chemist
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In regards to the persulfate, I know it works because it came up in an electrolysis book in the SM library. Sorry, I can't provide a reference as it
is late.
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Sulaiman
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for H2O2 maybe use sodium percarbonate ?
OTC OxiClean, Oxy Clean etc. non-bio whitener
(bleach, e.g. 2Na2CO3.3H2O2 → 2Na2CO3 + 3H2O2 ,when added to water)
better to buy 'pure' sodium percarbonate as the OTC is 15% to 30%
EDIT e.g. http://www.ebay.co.uk/itm/172032224041?_trksid=p2060353.m143...
[Edited on 7-1-2016 by Sulaiman]
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crystal grower
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I want to grow sulfur crystals from toluene solution
What do you think is the best technique?
Cooling heated solution or slow vaporisation of toluene ??
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j_sum1
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| Quote: Originally posted by crystal grower | I want to grow sulfur crystals from toluene solution
What do you think is the best technique?
Cooling heated solution or slow vaporisation of toluene ?? |
I did it with xylene a couple of months ago. Pix are in the pretty pictures thread.
Procedure was simple. I heated the xylene in a beaker and stirred in sulfur as it heated. At about 110C I had a nice yellow solution with a lot of S
in it. Maybe 40% by mass. Crystals grew as it cooled.
Interested in your results. Mine were long needles. I think toluene gives a more regular shape.
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crystal grower
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| Quote: Originally posted by j_sum1 | | Quote: Originally posted by crystal grower | I want to grow sulfur crystals from toluene solution
What do you think is the best technique?
Cooling heated solution or slow vaporisation of toluene ?? |
I did it with xylene a couple of months ago. Pix are in the pretty pictures thread.
Procedure was simple. I heated the xylene in a beaker and stirred in sulfur as it heated. At about 110C I had a nice yellow solution with a lot of S
in it. Maybe 40% by mass. Crystals grew as it cooled.
Interested in your results. Mine were long needles. I think toluene gives a more regular shape. |
Thanks for answer .
Aren't long needles more likely caused by high temperature than by type of dissolvent ??
[Edited on 7-1-2016 by crystal grower]
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arkoma
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have crude, dark KOH from oak ashes--decolorizing advice?
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
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blogfast25
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What you have is crude, dark K2CO3 from oak ashes.
Oak ashes don't contain any KOH, mainly K2CO3.
Try active charcoal or a bit of hydrogen peroxide to get rid of the brown stuff.
[Edited on 9-1-2016 by blogfast25]
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arkoma
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Thanx Blog. So to get KOH:
K2CO3 + HCl then electrolyze the resultant salt?
It was throwing me because of the high pH and the fact the leachate is referred to as "lye".
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
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blogfast25
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Easier: react it with slaked lime:
Ca(OH)2(s,aq) + K2CO3(aq) === > CaCO3(s) + 2 KOH(aq)
Filter off CaCO3.
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highpower48
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Ordering 1st ground glass joint glassware
I'm ordering my 1st ground glass joint glassware. It will be Chinese made( all I can afford right now) I know it's not the best, but I have a
question. Should I go with 24/29 or 24/40 joint sizes both seem to be about the same in pricing? I know that 24/40 is suppost to be the best, But
there does seem to be more variety in the 24/29 joint sizes. Just ordering a distillation kit and a vacuum filtering kit.
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Pyro
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It doesn't really matter, both are pretty much interchangeable.
If you really want to pick one, pick the one most used in your region. (US or Europe?)
all above information is intellectual property of Pyro.  |
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Texium
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9-1-2016 at 16:03 |
j_sum1
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I like 24/40. I think it gives a more robust joint. I have a little 24/29 and have not had any compatibility issues.
One advantage of the larger size: I chipped the edge of a flask. It is still usable. With a smaller joint there would have been insufficient surface
left to make a join.
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j_sum1
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I recently obtained some pool sanitiser -- active ingredient lithium hypochlorite.
On reading the MSDS I have found that it is only 30% LiOCl with the remainder, "alkaline components". A flame test gives the characteristic colour of sodium --
sufficient to mask any Li to the naked eye. I am going to guess in the absence of better information that the additional compound is either sodium
hydroxide or sodium carbonate. I intend some stage soon to do a titration to determine how much hypochlorite is there.
Any suggestions on how I might best determine the composition of what I have and also how to obtain a relatively pure lithium compound from this mix?
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Tabun
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Is there any book or something where I can check a substance's important proprierties like...toxicity?Especially related to nitro groups and
single/triple bonds.
[Edited on 12-1-2016 by Tabun]
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CitricAcid
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Sources of Phosphorus?
I would like to know about any other sources of phosphorus besides matchboxes. There is a website called onyxmet.com. I ordered a few grams of red P
to make phosphorus tribromide,which I ultimately used for methyl bromide. Since I will likely be visited by police if I try to order any more
phosphorus,I would like to know about any possible sources of P besides scraping matchboxes.
[Edited on 13-1-2016 by CitricAcid]
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macckone
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See the thread on making phosphorus using an aluminothermic reaction.
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UC235
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Why on earth would you use PBr3 for methyl bromide. A mixture of methanol, sulfuric acid, and NaBr is quite sufficient.
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j_sum1
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An answer
| Quote: Originally posted by The Chemistry Kingdom | Is it possible to obtain hydrogen peroxide from sodium persulfate
If you know the answer please reply I am cuurently looking at alternative methods for obtaining hydrogen peroxide because it is a bit costly
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| Quote: Originally posted by The Volatile Chemist | | In regards to the persulfate, I know it works because it came up in an electrolysis book in the SM library. Sorry, I can't provide a reference as it
is late. |
I have done a bit of research on this. See this thread and the resource I added.
http://www.sciencemadness.org/talk/viewthread.php?tid=16151&...
Another answer
| Quote: Originally posted by kemster90 | | Is there a chemical which can decompose bleach into oxygen without being consumed like maganese dioxide for sodium chlorate |
You can use CoCl2 as a catalyst. The hypochlorite will decompose quite readily liberating wet O2 gas. I don't think much Cl2 is liberated in the
process -- certainly not enough to smell.
If you are careful to not let the container overflow, then you can attempt to recover the CoCl2.
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Texium
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14-1-2016 at 06:01 |
HeYBrO
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| Quote: Originally posted by j_sum1 | Soluble starch
I have searched the forum and a few other places but have not found good answers to this question.
I am after some soluble starch for use in redox titrations. I know I can buy some from a chemical supplier but I was wondering about otc sources and
preparations. I didn't think it would be too hard -- in fact, it is probably so basic that no one writes much on it. Here is what I have tried and
my thoughts so far.
1. I have thus far used white rice and washed it with cold water and collected the water from it. This has been somewhat successful in the past but
my last attempt produced something that was not sensitive enough. I have also used hot water but always gotten a cloudy mixture that was not really
any better for the task.
2. I have read a few very simple procedures for obtaining potato starch. Basically juice a potato and dry it. I am not sure how good this would be
for iodometry. It is usually presented as a the first step in making a simple plastic product. I think that the starch obtained is quite soluble
though.
3. There are quite a number of starchy products available at the supermarket. What the Americans call cornstarch is called cornflour here and I am
not sure how it is processed or how it will act. Again, it is not that soluble. Arrowroot seems like it would be a better option. Alas,
old-fashioned laundry starch has been replaced by ezi-iron.
4. There are numerous papers available that describe ways of making starch more soluble. There are modified starches. There are procedures for
separating it from gluten and other proteins. It can be made into pre-gelatinised starch through a laborious process of soaking in DMSO and then
baking for a long period. There is also the possibility of treating it with alkali or "a salt" to make it more soluble. I am not sure how one then
effectively gets rid of the alkali or salt or even if it matters too much. I guess if I used ammonia then any excess would evaporate away.
So, (and I know I am probably overthinking this) what is the best course of action? Is juicing a potato ok? Or should I buy some tapioca flour? Is
it worth treating it in any way? Or is best to spend a couple of bucks at a chem supplier? |
did you see this: https://www.youtube.com/watch?v=rypuMg-r3zM?
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j_sum1
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Thanks HeYBrO.
That is a cool procedure with the glycerine. I have found that arrowroot is pretty soluble and seems to work quite well. I wonder if I could get an
even better product by combining the two approaches.
I also bookmarked that channel. It seems that there is quite a bit of good stuff there. Might be a language barrier in places however.
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RogueRose
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How do I identify ammonium bisulfate vs ammonium sulfate (has it converted to bisulfate)
When I was working on purification of Amm Sulfate, I wasn't aware that it would decompose to bisulfate at 212F. I allowed a pot of water/amm sulfate
solution to reach boiling and then evap'd some in an open glass dish at a temp above 212 (about 350 in oven actually). I had misread the properties
of sulfate and didn't know about this on my first run and in the middle of second.
I'm curious if everything in the pot that was in solution would have decomposed into the bisulfate or if it should be alright. Also what about the
part that was evap'd at 350.
I've tried finding info about the bisulfate and there is very little info about it and it's uses.
I can say that I noticed VERY little ammonia smell at any time during this process. I would say that the scent from a single spray of Windex would
have smelled stronger and lasted longer than the boiling and I noticed no smell during evap.
I would think that since the bisulfate looses 1/2 the ammonia per weight then I would have had a pretty strong smell of ammonia when doing this.
What do you guys think? Is there a way to test this?
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DraconicAcid
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If you dissolve some in water, ammonium bisulphate will be much more acidic than ammonium sulphate.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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annaandherdad
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Yes, and then you could neutralize it with ammonia and be back to ammonium sulfate.
Any other SF Bay chemists?
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Texium
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14-1-2016 at 21:20 |
RogueRose
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Removing water from Ammonia Cleaner
I was thinking about how corn meal is used in removing the last bit of water from alcohol, I think I have read that things like anhydrous MgSO4 can be
used as well.
Could either of these be used to absorb water from a standard ammonia cleaning solution?
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