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Author: Subject: The short questions thread (3)
dann2
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[*] posted on 28-8-2010 at 14:46


Hello,

I have SnCl4:5H2O (white solid) and I want to get to SnCl4 (clear liquid).

Can this be done?

TIA,
Dann2
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chemrox
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[*] posted on 28-8-2010 at 22:31


If it's soluble in toluene you could reflux it with a dean-stark until 5 eq of water are collected and distill to separate. The latter step under N2



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kuro96inlaila
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[*] posted on 31-8-2010 at 19:24


Hello,
Anyone have information(density,melting point,solubility etc) on silver(I) dichromate?
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jokull
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[*] posted on 31-8-2010 at 20:15


Hope these data would be helpful.

Silver dichromate:

Formula: Ag2Cr2O7
Solubility in water (15ÂșC): 0.083g/L
Density: 4.77 g/cm3
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kuro96inlaila
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[*] posted on 1-9-2010 at 15:27


Thanks.It do help.but I would love to receive any other data like its toxicity and uses.....
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hector2000
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[*] posted on 2-9-2010 at 01:40


We can make KİO3 by Oxidation of Kİ using KClO3 or KMnO4?



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Picric-A
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[*] posted on 2-9-2010 at 09:13


Does anybody know of an OTC source of methyl acrylate?

I am attempting to perform a Michael addition and i need this compound. If not, does anybody know of a synthesis for it that can be performed at lab scale?
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crazyboy
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[*] posted on 5-9-2010 at 17:22


I am looking for a vacuum controller so I can accurately measure and control the vacuum of my pump. There is a vacuum controller at the lab I worked at which connected the vacuum to the rotovap. It was small about 6" by 8" by 2". It had an simple digital display and several buttons, two arrows one up one down, two set point buttons, a run/stop button, a max vac button and a vent button.

The vacuum connected directly to the back of the controller and then went to the rotovap. I have looked on eBay but despite having several pages of vacuum controllers none have a vacuum port at the back, only electronic ports. Any advice? I can't have a computer in my lab.




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[*] posted on 12-9-2010 at 14:50


I use the jkem dvr to regulate my vacuum. Bought one off of ebay. It has two ports on the back. A vacuum in and the out port. It connects to the vacuum source and cycles a solenoid valve to control the vacuum precisely based on the setting.
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[*] posted on 16-9-2010 at 01:26


Making chloro-phenols can be done by simply bubbling Cl2 through a solution of phenol in water. I am only interested in making 2,4,6 trichlorophenol and don't want the others. Is this last compound the main product, or even the only product when Cl2 is passed through an aqueous solution of phenol?

Another more convenient method of making 2,4,6 trichlorophenol could be adding a solution of NaOCl or Ca(OCl)2 to a solution of phenol and then adding slight excess of HCl. The chlorine, formed in the solution, then immediately is used up by making chlorophenol. I tried this and the clear colorless solution becomes turbid on adding HCl and after a few minutes a big oily yellow/orange blob collects at the bottom. I used excess hypochlorite and after the reaction there is a faint smell of chlorine and some other somewhat "burned phenolic" smell. This smell is VERY persistent. Is this oily blob the desired 2,4,6 trichlorophenol?

[Edited on 16-9-10 by woelen]




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Jor
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[*] posted on 16-9-2010 at 06:10


You want the 2,4,6-trichlorophenol to make TCPO, the oxalate ester? If so, I would extract with DCM, wash the DCM with water, and distill off the DCM. This should give reasonably pure 2,4,6-trichlorophenol if this is your purpose, and some di- or mono-chlorinated impurities shouldn't really be a problem for the chemiluminescent experiment purpose.
You could use other solvents, but because it's so smelly I would want a solvent that boils of at an as low temperature as possible to prevent excessive evaporation of the compound.

I think it is trichlorphenol, because I have read somewhere that it indeed has a very persistent smell, and can be detected at around 1ppb. A reason why I would never make it, because I live near neighbours. And AFAIK, phenol and aniline are so reactive that they are directly chlorinated to the trichloro-compound with chlorine.

Maybe you could test it's acidity. It have not searched it, but it should be a quite acidic compound.



[Edited on 16-9-2010 by Jor]
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[*] posted on 16-9-2010 at 11:27


is there anyway of estimating the volume of an underground tank without emptying or filling it? The only viewing point i have for it is the standard 3 inch petroleum pipe coming up out of the floor, its full of diesel and is about 2 metres deep but have no idea of the girth.



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manimal
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[*] posted on 18-9-2010 at 23:30


I am going to try making a sealed stirrer out of a blender blade unit, tentatively by placing the housing over an appropriately-sized pvc pipe and tightening a hollowed-out endcap over it to seal the gasket, then by manipulating the blades so as to affix a stirring shaft.

I guess my question is, can anyone think of a better way in which to make a diy sealed stirrer?
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Panache
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[*] posted on 19-9-2010 at 16:38


Quote: Originally posted by manimal  
I am going to try making a sealed stirrer out of a blender blade unit, tentatively by placing the housing over an appropriately-sized pvc pipe and tightening a hollowed-out endcap over it to seal the gasket, then by manipulating the blades so as to affix a stirring shaft.

I guess my question is, can anyone think of a better way in which to make a diy sealed stirrer?


i would answer differently depending upon whether your system in under vacuum or pressure and if it is imperative for nothing to ingress or exit.

However i have designed and made and used over a couple of years now a 'sealed' stirrer that can be used for either with decent efficacy. There are some limitations however there are some ways those also.
I need to draw a diagram, i'll edit this post later after i have drawn and scanned it.




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Formula409
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[*] posted on 19-9-2010 at 19:45


Does anyone have any solubility data for n,n-dimethyltryptophan? Basically I'm looking for a way to separate it from tryptophan. I'm thinking the addition of the methyl groups should make it even less soluble in water (tryptophan is 11.4g/L (http://www.drugs.com/mmx/l-trytophan.html)).

Cheers!
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[*] posted on 20-9-2010 at 12:49


Would phenyl-2-propanol-1-one if formed possibly rearrange to phenylacetylcarbinol?
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ayush
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[*] posted on 25-9-2010 at 06:29




Will any one write what is the software used to generate this image?




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[*] posted on 25-9-2010 at 07:29


Can I extract Ethane1,2,diol from antifreeze safely by distillation?
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crazyboy
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[*] posted on 25-9-2010 at 07:41


Quote: Originally posted by ayush  


Will any one write what is the software used to generate this image?


I don't know the exact program used to create those images but a program called Mercury is apparently quite good and free.

Search for "Mercury - Crystal Structure Visualisation and Exploration Made Easy" It should be the first result.




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ayush
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[*] posted on 25-9-2010 at 09:13


Thank you crazyboy.



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entropy51
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[*] posted on 25-9-2010 at 11:11


Quote: Originally posted by Mossydie  
Can I extract Ethane1,2,diol from antifreeze safely by distillation?
I don't know if you can or not, but I have done it without problems. I used vacuum distillation since the BP is nearly 200 C at atmospheric pressure, which is quite a bit above the flash point. I used magnetic stirring because a solid separates out of the antifreeze that I distilled. Don't pour the waste out where animals could drink it. Dogs like it because it tastes sweet, but ingestion causes kidney failure.
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[*] posted on 25-9-2010 at 11:42


Would you consider it too dangerous at 1atm then? I have a mantle, so there won't be any sparks / flames anywhere around.
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[*] posted on 25-9-2010 at 12:11


You may get some decomposition depending on the additives. You can try it on a smaller scale with the brand you're planning to use; worth doing anyhow just to determine the rough amount of di- and tri ethylene glycols and other low volatility components.

Quote:
is there anyway of estimating the volume of an underground tank without emptying or filling it?

There's a method that's been used for spacecraft and such; basically you use a piston - a loudspeaker even - to change the air pressure, the pressure change in the system vs the piston excursion allows you to calculate the void space (air). To get the total volume you need to know the tank geometry, or do this when the tank is nearly empty, or do it at several differing depths of fill and estimate the geometry from the void/depth data.

Another possibility is to stick a bright LED and a video camera (webcam grade) in something like a large test tube, and lower that into the tank to image the interior. Only give you a rough idea, but perhaps good enough for corporation work.


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entropy51
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[*] posted on 25-9-2010 at 14:10


Quote: Originally posted by Mossydie  
Would you consider it too dangerous at 1atm then? I have a mantle, so there won't be any sparks / flames anywhere around.
I don't like to heat distillations to high temperatures if it can be avoided. I haven't looked up the autoignition temperature, but I have a feeling that it's too close for (my) comfort. If the glassware should break when the vapors are above the autoignition temperature it will flash without an ignition source.

If distilled at atmospheric pressure, don't run cooling water through the condenser, lest it break. Better to cool it with the air from a small fan.

Better to set yourself up for vacuum distillations.

Edit: After reading bbartlog's post, I looked up the autoignition temperature and found that it's 400 C. So perhaps an atmospheric distillation is safe after all. But I still just don't like to heat chemicals to a higher temperature than I have to. I'm getting too old to enjoy the excitement of a fire in the basement!

[Edited on 26-9-2010 by entropy51]

[Edited on 26-9-2010 by entropy51]
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[*] posted on 25-9-2010 at 17:30


Quote:

Would you consider it too dangerous at 1atm then? I have a mantle, so there won't be any sparks / flames anywhere around.


I've distilled ethylene glycol from commercial antifreeze at regular atmospheric pressure a number of times. Seems to work fine. I'm not sure why the flash point should be of particular interest; I mean people distill ethanol on a regular basis and it has a flash point below room temperature. In fact, based on a messy incident I had back before I even had (all) glass equipment (ethylene glycol and HCl spouting out of a flask which was above an open flame) I'd say that ethylene glycol is simply not very flammable at all.

But by all means distill at reduced pressure if you have the gear for it. Maintaining 197C (at least in my case) required using a fairly short path and insulating the neck of the flask. Lower temperature seems preferable if it's convenient.

[Edited on 26-9-2010 by bbartlog]
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