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Panache
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Does anyone have any actual real experience with the shelf stability of whinchesters of analR conc nitric acid? I picked some up for a song but its
circa late 90's (19 that is not 18, lol). The bottles are all unopened, i opened one and its essentially colourless with the density matching the
range quoted on the label. Vogel 3rd edition suggests running N2 through nitric to flush out the NO, No2's etc but i imagine in that decade the nitric
was far less pure than now.
I also got two whinchesters of analR n-hexane, anyone have suggestions for something interesting to do with this very pure paraffin?
Thirdly i also got a small amount (20L) of (manganese) parkerizing concenetrate. Looking into it it appears as this may be the perfect solution to my
iron retort bases constantly rusting up. Anyone parkerized anything before and subsequently used it in the laboratory? Tips? I'm fairly sure its
managanese base, but the MSDS says it contains nickel salts which is odd?
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UnintentionalChaos
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Why would nitric acid be that much less pure just 12 or so years ago? People have been making it for centuries, and lets face it, no matter what, it's
better than anything you distill yourself. The biggest difference between then and now is probably that nitric acid for trace metals analysis is now
available in PFA and FEP bottles which leach next to nothing (even compared to glass) into the acid.
if it's colorless and the bottle was sealed, it's as good as brand new. It has been properly stored for it's lifetime.
[Edited on 6-10-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Rich_Insane
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| Quote: |
What in the hell, may I ask, is an Ahlinn flask? |
I'm sorry, I meant to say condenser (long night  ). Just a bit on the narrow end
is chipped.
I'm wondering if it can be used , because that's where you would either put a desiccator, a thermometer or something, and there's usually adapters for
those.
Unfortunately the camera's broken (it's all red and fuzzy, probably the lens). By Chipped I meant rather small, perhaps a 1.5 cm2 piece of glass, or
2. The end isn't completely off, and the damage only goes for about 1 cm.
[Edited on 10-6-2009 by Rich_Insane]
[Edited on 10-6-2009 by Rich_Insane]
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UnintentionalChaos
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Narrow end? Is this a condenser with ground glass joints and the male cone is broken? If you can get a strip of grease all the way around the
remainder of the joint, it can still be used, but it may eventually break from strain on the preexisting damage.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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kclo4
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How much do you think this fume hood is worth?
http://www.thevespiary.org/0601091238.jpg
I'll try to get measurements later if its needed, but it is obviously only meant to be used by one person at a time. Maybe 40" wide?
It has an attachment for water, a small cone shaped "sink" below the water inlet. The cone sink my be 250ml? Also has an attachment for some sort of
gas such as natural gas or propane.
The fume hood also has a 24" fluorescent light above the glass on the entrance side.
It has very little rust, works perfectly, the hose has a hole in it, but will be fixed soon I'd think. The glass on the back comes up, and the shield
in front opens up.
Oh also, wtf does this go to, or how does it work? I'm sure it is a water distillation set up for the lab that is incomplete. It plugs in, but it
doesn't seem to do anything since there is no place to heat, etc. I haven't plugged it in yet though.
http://www.thevespiary.org/0601091523.jpg
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hissingnoise
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Panache, UC's reply to your query contained no insult, real, veiled or implied. . .
You, though, do seem to have some kind of problem.
And you owe UC an apology. . .
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Panache
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hmmmm,
perhaps i over-reacted.
UC, i apologise whole-heartedly if your response was meant in an inquisitive manner, if it was meant in a snide manner, i stand by what i accuse you
of. Please respond as to whether it was the former or the latter.
Thank-you hissinghoise for bringing this up.
[Edited on 10-6-2009 by Panache]
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hissingnoise
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We all have "our moments", Panache, and you've done the right thing. . .
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einstein(not)
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I have approx. 5lbs. of calcium sulfate (perhaps calcium hydrogen sulfate) left over from the production of nitric acid via calcium nitrate
(fertilizer grade) and sulfuric acid (drain opener). What do I actually have and what would be the best way to purify it for later use?
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User
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Well if calcium(hydrogen)sulfate is strongly heated one can obtain SO3.
First calciumpyrosulfate will appear due to the loss of water.
When heated further ->500deg pure SO3 will come over.
Heating it very strongly would be a start cleaning it.
Also , when a solid nitrate is added and heated nitric vapors appear. They would be heavily decomposed under influence of the heat required.
[Edited on 11-6-2009 by User]
What a fine day for chemistry this is.
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kclo4
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Solubility, and pH will determine if it is calcium hydrogen sulfate or calcium sulfate.
I personally think if it is calcium hydrogen sulfate you can add it to water to get dilute sulfuric acid as the calcium sulfate precipitates. If you
add calcium sulfate to sulfuric acid/water it doesn't dissolve into calcium hydrogen sulfate the last time I checked. If it does, I am missing out!
So what I would do to purify it is just rinse it with water until it has a neutral pH. Calcium sulfate is hardly soluble in water but it can be very
annoying and remain in the solution as small particles for a long time.
If I were doing this and were serious about yield I would boil/reflux the solution + calcium sulfate to get larger CaSO4 crystals. It would help
break the suspension and make it easier to filter. Attempting to filter CaSO4 is often a mistake, and I would decant off the solution above it then
rinse with distilled water to get rid of any acids or soluble salts, etc.
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einstein(not)
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I'm having trouble with the reaction equation. Ca(NO3)2 + 2H2SO4 -----> 2CaSO4 + 2HNO3 + H I don't beleive any hydrogen was evolved so
obviously I've got something wrong. Right?!?
[Edited on 11-6-2009 by einstein(not)]
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hissingnoise
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That should be: Ca(NO3)2 + H2SO4--->CaSO4 + 2HNO3. . .
Yay! Your H2SO4 is going twice as far!
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einstein(not)
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Thanks!
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UnintentionalChaos
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Calcium sulfate, as it turns out, is appreciably (as appreciable as a typically "completely insoluble" powder can be) soluble in nitric acid
solutions. I learned this the hard way in one of those "identify this white powder" labs in inorganic chemistry. "Oh, a little spatula dissolved in
nitric acid, so it can't be CaSO4" This of course was before I knew what Ksp was. Distillation is in order to get clean acid.
[Edited on 6-12-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Formula409
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Can Methyl Tosylate be made by simple Fischer Esterification of p-Toluenesulfonic acid?
Formula409.
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hissingnoise
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So. . .Thinking I hadda way of making hexamine dinitrate sans HNO3, I dissolved a small quantity of dry NH4NO3 in a little fresh formalin.
I expected the formalin smell to fade as the NH4NO3 reacted but after adding more than enough to bind up the CH2O the choking smell was undiminished.
. .
I decided to evaporate the solution to dryness; the smell of hot aldehyde reached my kitchen door and my ball-and-cha. . .er, my good wife picked up
on it.
At around 100*C the CH2O smell faded somewhat, being replaced largely, by the smell of NO2.
The residue which formed was white at first, slowly becoming orange-coloured and flatly refused to dry, so it was heated strongly again and the NO2
smell began to take on a fishy character.
Now I've got a wet, orangey-amber gloop which smells alternately of HNO3 and CH3NH2.
I dunno, the methanol stabiliser might have complicated things.
The original idea was to nitrolyse the dried HDN to RDX, thereby saving on HNO3.
Has anyone else tried doing this?
Or have any thoughts on the reaction. . .
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UnintentionalChaos
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Does anyone know a cheap supplier or happen to have a spare PTFE stopcock I can buy off of them?
I need a 1:5 taper 15.2/30 with a single 3 or 4mm straight bore. I could also use a single PTFE washer for a 11/25 stopcock, although I can deal
without it. Thanks
hissingnoise-
the reaction of formaldehyde with ammonia to produce hexamine probably proceeds via a methylimine intermediate, which requires nucleophilic ammonia to
react with the formaldehyde. Ammonium ion is not a nucleophile and ammonium nitrate solution is mildly acidic, keeping the concentration of free
ammonia very low.
The gunk left over probably contains a lot of paraformaldehyde and ammonium nitrate. Small amounts of condensation probably occured despite the
acidity, which is where the methylamine smell is coming from. perhaps methylimine copolymerized with the formaldehyde? I'm guessing wildly here.
[Edited on 6-14-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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not_important
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Remember the old standard method for making the methylamines is to heat a mixture of formaldehyde and ammonium chloride, I suspect that the same
reaction is occurring.
Do consider that if secondary amines are formed, then it is likely that nitrosoamines will also be formed.
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hissingnoise
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Thanks guys. Hexamine dinitrate is likely to be thermally unstable so heating the solution was a mistake, it seems. . .
But the ease with which hexamine is obtained from 4NH3 + 6CH2O threw me off.
Evaporation under (greatly) reduced pressure should give the dinitrate but I'm having some work done on my house and the plumbing is in a state of
limbo, right now.
In theory, though, solutions of NH4NO3 in formalin should contain hexamine and enough HNO3 to form RDX.
Adding excess acetic anhydride should precipitate RDX since that is the synthesis that replaced direct nitration. . .
Yes, I know paraform is used in practise but the principle is the same.
If I tried dessicating the solution over H2SO4 would H2O be removed without affecting the HNO3 also present, does anyone know?
[Edited on 14-6-2009 by hissingnoise]
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User
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For the record , why not make HDN out of HCl, AN and hex. ?
It does't give good yields, but kilo's could be made for just a couple a bucks.
It seems cheap enough to me.
What a fine day for chemistry this is.
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hissingnoise
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Two reasons User,---I'm low on HCl and hexamine and I have a surplus of AN and formalin, and the formalin route has a hint of novelty about it. . .
And the reaction of formalin with ammonium salts is supposed to release the acid!
It's also possible that at low pressure, (dilute) HNO3 could be distilled from the solution.
But it's all guesswork. . .
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Rich_Insane
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Would you dissolve menthol with a polar or nonpolar solvent?
I have figured out that the hydroxyl group in menthol makes it polar on that side. The solubility in water is listed as "slightly soluble".
[Edited on 17-6-2009 by Rich_Insane]
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497
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Two questions that shouldn't be too hard to answer:
1. In general, will methods of reductive amination for ketones also apply to aldehydes with similar yields? Are there any general differences?
2. Is there an appreciable difference between oxidation of benzyl alcohols and 2-phenethyl alcohols? For example, a catalytic H2O2 oxidation of benzyl
alcohols yields 95% benzaldehyde, will it be similar for 2-phenethyl alcohol to phenylacetaldehyde?
Edit: I think I've answered #1 for myself, so cancel that one..
[Edited on 19-6-2009 by 497]
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UnintentionalChaos
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Quote: Originally posted by 497  |
2. Is there an appreciable difference between oxidation of benzyl alcohols and 2-phenethyl alcohols? For example, a catalytic H2O2 oxidation of benzyl
alcohols yields 95% benzaldehyde, will it be similar for 2-phenethyl alcohol to phenylacetaldehyde? |
The oxidation of 2-phenylethanol will proceed much like the oxidation of ethanol. The benzylic position confers special reactivity to benzyl alcohols,
halides, etc due to the benzyl carbon's relation with the pi-cloud.
[Edited on 6-19-09 by UnintentionalChaos]
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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