Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
 Pages:  1  ..  3    5    7  ..  104
Author: Subject: The Short Questions Thread (4)
bbartlog
International Hazard
*****




Posts: 1139
Registered: 27-8-2009
Location: Unmoored in time
Member Is Offline

Mood: No Mood

[*] posted on 10-11-2013 at 12:15


Seems like you'd first need to hydrolyze it to monomers, and then convert it to dioxane via some means such as heating with sulfuric acid. Those individual steps should be easy enough to research, I know that the latter at least has been discussed on this forum.



The less you bet, the more you lose when you win.
View user's profile View All Posts By User
confused
Hazard to Others
***




Posts: 244
Registered: 17-3-2013
Location: Singapore
Member Is Offline

Mood: tired

[*] posted on 17-11-2013 at 15:54
Question


would calcium hydroxide work for a base catalysed hydrolysis of acetylsalicyclic acid to salicyclic acid?
is there any way to know when the reaction has come to completion?
View user's profile View All Posts By User
UnintentionalChaos
International Hazard
*****




Posts: 1454
Registered: 9-12-2006
Location: Mars
Member Is Offline

Mood: Nucleophilic

[*] posted on 17-11-2013 at 16:16


Quote: Originally posted by confused  
would calcium hydroxide work for a base catalysed hydrolysis of acetylsalicyclic acid to salicyclic acid?
is there any way to know when the reaction has come to completion?


Boiling water is enough to get the decomposition going, so I'm going to say "yes."




Department of Redundancy Department - Now with paperwork!

'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
View user's profile View All Posts By User
Lambda-Eyde
National Hazard
****




Posts: 860
Registered: 20-11-2008
Location: Norway
Member Is Offline

Mood: Cleaved

[*] posted on 17-11-2013 at 16:20


If I'm going to guess, calcium salicylate won't be very soluble. Boiling water works, but adding a few drops HCl speeds it up and makes the workup easier.



This just in: 95,5 % of the world population lives outside the USA
Please drop by our IRC channel: #sciencemadness @ irc.efnet.org
View user's profile View All Posts By User
I Like Dots
Hazard to Self
**




Posts: 69
Registered: 10-4-2013
Member Is Offline

Mood: frisky

[*] posted on 19-11-2013 at 17:24


Where can I find general a procedure on forming ketone and aldehyde sodium bisulfite adducts?
http://www.erowid.org/archive/rhodium/chemistry/eleusis/bisu... This is the closest I have gotten.

I plan on separating the benzaldehyde from almond extract. Im going to try with acetone also.




View user's profile View All Posts By User
SHADYCHASE54
Hazard to Others
***




Posts: 150
Registered: 16-12-2010
Location: CaNaDay!
Member Is Offline

Mood: No Mood

[*] posted on 27-11-2013 at 08:06


I have a quick question regarding removing the acetyl group from n-acetyl-4-piperidone what I am wondering is were I to reflux with a slight molar excess of potassium hydroxide will I shed the acetyl leaving the 4-piperidone in tact? If you have any experience I would love to hear from you as well if you might have any pertinent refs all aid would be appreciated.
View user's profile View All Posts By User
plante1999
International Hazard
*****




Posts: 1936
Registered: 27-12-2010
Member Is Offline

Mood: Mad as a hatter

[*] posted on 28-11-2013 at 14:29


Does anyone know where I can find a good preparation for:

Diethyl azodicarboxylate

Thanks!




I never asked for this.
View user's profile View All Posts By User
plante1999
International Hazard
*****




Posts: 1936
Registered: 27-12-2010
Member Is Offline

Mood: Mad as a hatter

[*] posted on 28-11-2013 at 15:32


Quote: Originally posted by plante1999  
Does anyone know where I can find a good preparation for:

Diethyl azodicarboxylate

Thanks!


You can see it here, thanks me latter:

http://www.orgsyn.org/Content/pdfs/procedures/CV4P0411.pdf





I never asked for this.
View user's profile View All Posts By User
Pyro
International Hazard
*****




Posts: 1305
Registered: 6-4-2012
Location: Gent, Belgium
Member Is Offline

Mood: No Mood

[*] posted on 29-11-2013 at 11:19


I distilled technical quality toluene, to keep it completely anhydrous I added a few thin flakes of pure Na.
two days later they look like this:
WP_20131129_001.jpg - 80kB
what could there be in redistilled toluene that turns brown in contact with Na or NaOH?

Do I need to distill it again, or can I get away with filtration? (400ml)




all above information is intellectual property of Pyro. :D
View user's profile View All Posts By User
elementcollector1
International Hazard
*****




Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

[*] posted on 29-11-2013 at 12:36


Seems like sodium oxide - I get that brown/yellow finish on my sodium as well. Not in toluene, though.



Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
View user's profile View All Posts By User
Pyro
International Hazard
*****




Posts: 1305
Registered: 6-4-2012
Location: Gent, Belgium
Member Is Offline

Mood: No Mood

[*] posted on 30-11-2013 at 12:02


Ok, thanks. Do I need to re-distill it or can I just filter the floating ''stuff'' out?



all above information is intellectual property of Pyro. :D
View user's profile View All Posts By User
elementcollector1
International Hazard
*****




Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

[*] posted on 30-11-2013 at 13:18


Quote: Originally posted by Pyro  
Ok, thanks. Do I need to re-distill it or can I just filter the floating ''stuff'' out?

Should probably re-distill it, but either way works. The 'stuff' should also keep your solution dry, so best to keep it in there long-term.




Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
View user's profile View All Posts By User
Pyro
International Hazard
*****




Posts: 1305
Registered: 6-4-2012
Location: Gent, Belgium
Member Is Offline

Mood: No Mood

[*] posted on 30-11-2013 at 13:20


the Na sinks in toluene, but the stuff looks like scurf and floats around :)



all above information is intellectual property of Pyro. :D
View user's profile View All Posts By User
bismuthate
National Hazard
****




Posts: 803
Registered: 28-9-2013
Location: the island of stability
Member Is Offline

Mood: self reacting

[*] posted on 30-11-2013 at 15:50


How would FeCl3 react with sodium acetate?



I'm not a liar, I'm just an enthusiastic celebrant of opposite day.
I post pictures of chemistry on instagram as bismuthate. http://iconosquare.com/bismuthate
or this viewer if you don't have an instagram (it sucks though) http://web.stagram.com/n/bismuthate
View user's profile Visit user's homepage View All Posts By User
DraconicAcid
International Hazard
*****




Posts: 4332
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline

Mood: Semi-victorious.

[*] posted on 30-11-2013 at 18:00


Quote: Originally posted by bismuthate  
How would FeCl3 react with sodium acetate?


Probably through hydrolysis. Fe3+ + H2O + OAc- -> Fe(OH)2+ + HOAc.

With enough acetate ion, you'll get iron(III) hydroxide precipitating.




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.
View user's profile View All Posts By User
BlackDragon2712
Hazard to Others
***




Posts: 124
Registered: 22-12-2012
Location: Everywhere
Member Is Offline

Mood: Sleepy

[*] posted on 1-12-2013 at 17:14


Question

does anyone knows where to get tert-butanol?

[Edited on 06/11/2013 by BlackDragon2712]
View user's profile View All Posts By User
plante1999
International Hazard
*****




Posts: 1936
Registered: 27-12-2010
Member Is Offline

Mood: Mad as a hatter

[*] posted on 1-12-2013 at 17:31


I do.



I never asked for this.
View user's profile View All Posts By User
elementcollector1
International Hazard
*****




Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

[*] posted on 1-12-2013 at 17:33


Quote: Originally posted by BlackDragon2712  
Question

does anyone knows where to get tert-butanol?

[Edited on 06/11/2013 by BlackDragon2712]

U2U sent regarding potential availability. Unfortunately, I have no idea where you live...




Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
View user's profile View All Posts By User
chemrox
International Hazard
*****




Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: LaGrangian

[*] posted on 1-12-2013 at 20:40


Quote: Originally posted by I Like Dots  
Where can I find general a procedure on forming ketone and aldehyde sodium bisulfite adducts?
http://www.erowid.org/archive/rhodium/chemistry/eleusis/bisu... This is the closest I have gotten.

I plan on separating the benzaldehyde from almond extract. Im going to try with acetone also.


Check the library here. This is covered in "purification of laboratory chemicals."

I would do a fractional distillation first. You could skip the bisulfite step as most oil of bitter almond is 98% (or more) benzaldehyde.





"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
View user's profile View All Posts By User
chemrox
International Hazard
*****




Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: LaGrangian

[*] posted on 1-12-2013 at 20:53


Quote: Originally posted by SHADYCHASE54  
I have a quick question regarding removing the acetyl group from n-acetyl-4-piperidone what I am wondering is were I to reflux with a slight molar excess of potassium hydroxide will I shed the acetyl leaving the 4-piperidone in tact? If you have any experience I would love to hear from you as well if you might have any pertinent refs all aid would be appreciated.


Try strong base in ethylene glycol or DMSO. 4-piperidone polymerizes on formation so it is sold as the dihydro-HCl. The water molecules are a formality since it is actually a diketal. Let me know how it goes or send me what you've got and I'll give you an eq amt of the product of commerce.




"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
View user's profile View All Posts By User
bismuthate
National Hazard
****




Posts: 803
Registered: 28-9-2013
Location: the island of stability
Member Is Offline

Mood: self reacting

[*] posted on 5-12-2013 at 15:19


Does anybody know a solvent for calcium/alkali metal carbides?



I'm not a liar, I'm just an enthusiastic celebrant of opposite day.
I post pictures of chemistry on instagram as bismuthate. http://iconosquare.com/bismuthate
or this viewer if you don't have an instagram (it sucks though) http://web.stagram.com/n/bismuthate
View user's profile Visit user's homepage View All Posts By User
DraconicAcid
International Hazard
*****




Posts: 4332
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline

Mood: Semi-victorious.

[*] posted on 5-12-2013 at 15:25


Calcium carbide is actually an acetylide- a strong base, but one can work with it. Avoid esters and alcohols, obviously, but you need something polar or it won't dissolve. Acetonitrile is probably to acidic; acetone is too vulnerable to nucleophilic attack...I'd try THF. Even if it's not very soluble, it might disperse enough to be a good reaction medium.

For an alkali metal acetylide, you might be able to make it more soluble by adding TMEDA (tetramethylethylenediamine).

[Edited on 5-12-2013 by DraconicAcid]




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.
View user's profile View All Posts By User
bismuthate
National Hazard
****




Posts: 803
Registered: 28-9-2013
Location: the island of stability
Member Is Offline

Mood: self reacting

[*] posted on 5-12-2013 at 15:39


(I don't know much about organic chem so I may say something stupid)From what I have seen on SM CaC2 does not seem to react with ethanol. Might it be slightly soluble in that? I would also wonder about liquid ammonia.

[Edited on 5-12-2013 by bismuthate]




I'm not a liar, I'm just an enthusiastic celebrant of opposite day.
I post pictures of chemistry on instagram as bismuthate. http://iconosquare.com/bismuthate
or this viewer if you don't have an instagram (it sucks though) http://web.stagram.com/n/bismuthate
View user's profile Visit user's homepage View All Posts By User
elementcollector1
International Hazard
*****




Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline

Mood: Molten

[*] posted on 7-12-2013 at 23:03


Online sources typically state the concentration of selenium in dietary supplements to be 200 micrograms per tablet. Considering each tablet weighs considerably more than 200 ug, what's the rest?



Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
View user's profile View All Posts By User
confused
Hazard to Others
***




Posts: 244
Registered: 17-3-2013
Location: Singapore
Member Is Offline

Mood: tired

[*] posted on 8-12-2013 at 00:00


my guess would be binders,preservatives and flavors or sweeteners
http://en.wikipedia.org/wiki/Excipient
View user's profile View All Posts By User
 Pages:  1  ..  3    5    7  ..  104

  Go To Top