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Author: Subject: The Short Questions Thread (4)
idk_something
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[*] posted on 30-5-2018 at 04:27
Question


How well does Helium store? I'd like to buy a tank from a gas supplier for a rainy day as the price of Helium is set to rise in the coming years. How much should I expect to lose if I store it properly in a fairly cool and dry environment? <26c
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DavidJR
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[*] posted on 30-5-2018 at 07:21


I wouldn't have thought you'd lose any at all, the cylinder shouldn't leak appreciably.



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Panache
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[*] posted on 30-5-2018 at 23:30


Quote: Originally posted by mackolol  
So would it work if i tried to steam distill formamide or diethyl sulphate?


The general rule is your substrate (the compound you are wanting to distill) should be between 1-3% soluble in water, any more or less no go. This is if you are using the shit method (no external steam).
I highly endorse using external steam. At home i simply use one of those handheld steam units for cleaning curtains they are like $30. With higher pressures a greater range of compounds can be steam distilled and your efficiency is maximised.
If your current setup can't handle condensing all that steam simply lead the outlet vapours onto a big block of ice sitting in a bowl or something.
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Σldritch
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[*] posted on 4-6-2018 at 04:50


Are carboxylate groups electron donating or withdrawing?
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egret
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[*] posted on 15-6-2018 at 13:41
Question


Hello everybody
Its my first post here. I atempt a reduction of nitrobenzene by zinc in sulphuric acid. I got a purple coloured solution after filtration of unreacted zinc. Do anybody knows why the the filtrate has a such colour? May be an oxidation product of aniline?

filtrate.jpg - 170kB
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ninhydric1
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[*] posted on 17-6-2018 at 19:56


Does methanol and ethanol form an azeotrope? If yes, what temperature and what composition? (I tried googling but I couldn't find any data on it)



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j_sum1
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[*] posted on 17-6-2018 at 21:21


Quote: Originally posted by ninhydric1  
Does methanol and ethanol form an azeotrope? If yes, what temperature and what composition? (I tried googling but I couldn't find any data on it)

Not according to Wikipedia. Not that I would put too much confidence in that -- the data appears to have gaps and is set out like a dog's breakfast. However, if one existed it would surely be mentioned...?




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stamasd
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[*] posted on 18-6-2018 at 03:41


Quote: Originally posted by egret  
Hello everybody
Its my first post here. I atempt a reduction of nitrobenzene by zinc in sulphuric acid. I got a purple coloured solution after filtration of unreacted zinc. Do anybody knows why the the filtrate has a such colour? May be an oxidation product of aniline?


I haven't done anything with aniline for many years (20 or so) but I remember back in the day that aniline stored in non-airtight conditions would become a similar color after a while. So yes, probably oxidation products is correct. Also probably some condensation products caused by the sulfuric acid. IIRC HCl is typically used for the reduction instead of H2SO4 to minimize such side reactions.


[Edited on 18-6-2018 by stamasd]
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ninhydric1
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[*] posted on 18-6-2018 at 11:41


That's what I thought too, j_sum. I'll search around a bit longer and see but there most likely isn't one.



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egret
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[*] posted on 18-6-2018 at 13:36


Quote: Originally posted by ninhydric1  
Does methanol and ethanol form an azeotrope? If yes, what temperature and what composition? (I tried googling but I couldn't find any data on it)


Acording source below it does not form azeotrope
http://www.ddbst.com/en/EED/VLE/VLE%20Ethanol%3BMethanol.php

stamasd thank you for explanation

[Edited on 19-6-2018 by egret]
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CharlieA
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[*] posted on 18-6-2018 at 16:14


My Lange's Handbook of Chemistry, 15th edition, did not have an EtOH/MeOH binary azeotrope, nor a ternary water/EtOH/MeOH azeotrope.
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[*] posted on 19-7-2018 at 03:32


Is there any reagent that helps detecting oximes in mixture? (changes color if oxime is present)
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clearly_not_atara
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[*] posted on 19-7-2018 at 10:53


Quote: Originally posted by egret  
Hello everybody
Its my first post here. I atempt a reduction of nitrobenzene by zinc in sulphuric acid. I got a purple coloured solution after filtration of unreacted zinc. Do anybody knows why the the filtrate has a such colour? May be an oxidation product of aniline?

Likely a complex involving p-aminophenol:

http://labmonk.com/synthesis-of-p-aminophenol-from-nitrobenz...
http://www.sciencemadness.org/talk/viewthread.php?tid=27849
http://shodhganga.inflibnet.ac.in/bitstream/10603/126633/11/...

Apparently zinc and acids converts nitrobenzene to phenylhydroxylamine which rearranges to p-aminophenol. Usually this is done in two steps with Zn/NH4Cl for reduction and H2SO4 for rearrangement.




[Edited on 04-20-1969 by clearly_not_atara]
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clearly_not_atara
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[*] posted on 25-7-2018 at 11:56


Can methylsulfuric acid quaternize amines? For example, could trimethylammonium methylsulfate -- (Me3NH+)(MeOSO3-) -- rearrange to tetramethylammonium bisulfate?

Quote: Originally posted by mackolol  
Is there any reagent that helps detecting oximes in mixture? (changes color if oxime is present)

"Oximes couple in alkaline media with aryldiazonium salts to give arylazobis(oximes) which develop an intense blue color with ferric chloride; 50 micrograms of oxime can be detected in 25 mL of solution"

https://link.springer.com/article/10.1007%2FBF01219641 (attached)

[Edited on 25-7-2018 by clearly_not_atara]

Attachment: bhargava1970.pdf (100kB)
This file has been downloaded 244 times





[Edited on 04-20-1969 by clearly_not_atara]
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[*] posted on 26-7-2018 at 06:22


is the carbonyl on urea reducible with NaBH4?



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clearly_not_atara
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[*] posted on 26-7-2018 at 19:58


Maybe with in situ formation of diborane?

http://www.thevespiary.org/rhodium/Rhodium/chemistry/borohyd...

Are you hoping to obtain formamidine? Or something else? If you reduce to formaldehyde aminal, it will probably rearrange to hexamine + NH3. Maybe it will go all the way to methylamine?

[Edited on 27-7-2018 by clearly_not_atara]




[Edited on 04-20-1969 by clearly_not_atara]
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[*] posted on 27-7-2018 at 08:23


No particular desires. Got 30g NaBH4 and hunting a project and I have lots of clean urea and anhydrous isopropanol. I always forget about the vespiary.....



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JJay
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[*] posted on 4-8-2018 at 01:01


Did Chem Player have a video on making nickel boride? I'm not seeing it on Bitchute....



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[*] posted on 4-8-2018 at 10:09


Quote: Originally posted by JJay  
Did Chem Player have a video on making nickel boride? I'm not seeing it on Bitchute....


I believe they did; https://smvideo.djr.pw/watch/4/nickel-chloride-and-boride/
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[*] posted on 9-8-2018 at 22:49


Damn. Is that one we missed in the Bitchute upload?



Watch some vintage ChemPlayer: https://www.bitchute.com/channel/chemplayer/
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JJay
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[*] posted on 10-8-2018 at 00:43


I think so. I hope you post some more. I keep watching for new Chem Player videos. :cool:



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[*] posted on 10-8-2018 at 08:08


Insanely busy with other projects at the moment unfortunately, but will try to keep them coming!



Watch some vintage ChemPlayer: https://www.bitchute.com/channel/chemplayer/
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[*] posted on 10-8-2018 at 19:57


Just for you ;)
https://www.bitchute.com/video/46uwCCGlPMA1/




Watch some vintage ChemPlayer: https://www.bitchute.com/channel/chemplayer/
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JJay
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[*] posted on 10-8-2018 at 20:21


Thanks! :)



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[*] posted on 13-8-2018 at 00:53
Can sodium metal be used for THF drying?


How to dry tetrahydrofuran (THF)? Can you use sodium metal like you use when drying ether? Or THF will react with the sodium metal?

[Edited on 13-8-2018 by experimenter_]
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