| Pages:
1
..
84
85
86
87
88
..
103 |
idk_something
Harmless
Posts: 3
Registered: 21-4-2018
Member Is Offline
Mood: No Mood
|
|
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
|
|
|
DavidJR
National Hazard
Posts: 908
Registered: 1-1-2018
Location: Scotland
Member Is Offline
Mood: Tired
|
|
I wouldn't have thought you'd lose any at all, the cylinder shouldn't leak appreciably.
|
|
|
Panache
International Hazard
Posts: 1290
Registered: 18-10-2007
Member Is Offline
Mood: Instead of being my deliverance, she had a resemblance to a Kat named Frankenstein
|
|
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.
|
|
|
Σldritch
Hazard to Others
Posts: 309
Registered: 22-3-2016
Member Is Offline
Mood: No Mood
|
|
Are carboxylate groups electron donating or withdrawing?
|
|
|
egret
Harmless
Posts: 20
Registered: 22-2-2018
Member Is Offline
Mood: No Mood
|
|
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?
|
|
|
ninhydric1
Hazard to Others
Posts: 345
Registered: 21-4-2017
Location: Western US
Member Is Offline
Mood: Bleached
|
|
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)
The philosophy of one century is the common sense of the next.
|
|
|
j_sum1
Administrator
Posts: 6219
Registered: 4-10-2014
Location: Unmoved
Member Is Offline
Mood: Organised
|
|
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...?
|
|
|
stamasd
Hazard to Others
Posts: 133
Registered: 24-5-2018
Location: in the crosshairs
Member Is Offline
Mood: moody
|
|
| 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]
|
|
|
ninhydric1
Hazard to Others
Posts: 345
Registered: 21-4-2017
Location: Western US
Member Is Offline
Mood: Bleached
|
|
That's what I thought too, j_sum. I'll search around a bit longer and see but there most likely isn't one.
The philosophy of one century is the common sense of the next.
|
|
|
egret
Harmless
Posts: 20
Registered: 22-2-2018
Member Is Offline
Mood: No Mood
|
|
| 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]
|
|
|
CharlieA
National Hazard
Posts: 645
Registered: 11-8-2015
Location: Missouri, USA
Member Is Offline
Mood: No Mood
|
|
My Lange's Handbook of Chemistry, 15th edition, did not have an EtOH/MeOH binary azeotrope, nor a ternary water/EtOH/MeOH azeotrope.
|
|
|
mackolol
Hazard to Others
Posts: 458
Registered: 26-10-2017
Member Is Offline
Mood: Funky
|
|
Is there any reagent that helps detecting oximes in mixture? (changes color if oxime is present)
|
|
|
clearly_not_atara
International Hazard
Posts: 2692
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
| 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]
|
|
|
clearly_not_atara
International Hazard
Posts: 2692
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
Can methylsulfuric acid quaternize amines? For example, could trimethylammonium methylsulfate -- (Me3NH+)(MeOSO3-) -- rearrange to tetramethylammonium
bisulfate?
"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 457 times
[Edited on 04-20-1969 by clearly_not_atara]
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
is the carbonyl on urea reducible with NaBH4?
"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
|
|
|
clearly_not_atara
International Hazard
Posts: 2692
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
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]
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
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.....
"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
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Did Chem Player have a video on making nickel boride? I'm not seeing it on Bitchute....
|
|
|
Σldritch
Hazard to Others
Posts: 309
Registered: 22-3-2016
Member Is Offline
Mood: No Mood
|
|
I believe they did; https://smvideo.djr.pw/watch/4/nickel-chloride-and-boride/
|
|
|
chemplayer...
Hazard to Others
Posts: 191
Registered: 25-4-2016
Location: Away from the secret island
Member Is Offline
Mood: No Mood
|
|
Damn. Is that one we missed in the Bitchute upload?
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
I think so. I hope you post some more. I keep watching for new Chem Player videos. 
|
|
|
chemplayer...
Hazard to Others
Posts: 191
Registered: 25-4-2016
Location: Away from the secret island
Member Is Offline
Mood: No Mood
|
|
Insanely busy with other projects at the moment unfortunately, but will try to keep them coming!
|
|
|
chemplayer...
Hazard to Others
Posts: 191
Registered: 25-4-2016
Location: Away from the secret island
Member Is Offline
Mood: No Mood
|
|
Just for you 
https://www.bitchute.com/video/46uwCCGlPMA1/
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Thanks! 
|
|
|
experimenter_
Harmless
Posts: 38
Registered: 18-2-2016
Member Is Offline
Mood: No Mood
|
|
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_]
|
|
|
| Pages:
1
..
84
85
86
87
88
..
103 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
