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

Printable Version  
 Pages:  1  ..  20    22    24  ..  66
Author: Subject: Make Potassium (from versuchschemie.de)
len2
Harmless
*




Posts: 32
Registered: 13-9-2008
Member Is Offline

Mood: No Mood

[*] posted on 29-12-2010 at 21:37


Very interesting result Nurdrage. I have not thought of tetralin - and we have none in any of the labs - when when I get a chance Ill try it. The reason the reaction goes slow in heavy paraffins is that the alkoxides are not very soluble in them - even the t-alcohol doesnt dissolve all that easily. The aromatic gets around that problem.

I find the structure on the surface of K obtained this way puzzling. My electrolytic potassium never showed it
View user's profile View All Posts By User
NurdRage
Hazard to Others
***




Posts: 182
Registered: 11-11-2010
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 04:14


There is no structure, actually the potassium is still molten and it's shiny surface is reflecting the back of my fume hood. So don't read into it too much ;)


As for Tetralin, it's not easy to get so as a solvent i don't think it's viable for the amateur. The closest domestic thing i can think of is naphthalene, which is somewhat easier. Since it's solid, I think a mixture of naphthalene and paraffin might have all the properties we want of wide liquid range and high density.

Problem is the odor.


Nonetheless, with the realization that aromatics are viable again we can expand our solvent search.
View user's profile View All Posts By User
condennnsa
Hazard to Others
***




Posts: 217
Registered: 20-4-2010
Location: Romania
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 04:22


Nice work, nurdrage. The naphthalene option is very interesting, do you think you could also run a test with paraffin-naphthalene mixture? naphthalene also has a remarkably high density of 1.14 .

I would try it, but still got no alcohol.

There might be problems with naphthalene which could deposit in solid layer on the cool part of the refluxer...
View user's profile View All Posts By User
NurdRage
Hazard to Others
***




Posts: 182
Registered: 11-11-2010
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 04:39


Yeah i'm worried about that too. I'm hoping careful choice of a lower boiling paraffin might wash down any solid naphthalene that gets up there.

I'm still looking into it. when the holidays are over i'll be able to acquire more materials to test.
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 7722
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 30-12-2010 at 05:09


@Nurdrage: I just am reading now and have no time for experimenting, as I am too much occupied by family matters the last week, but your result with the tetralin is great. That really is a breakthrough in this type of reaction. I'll modify my webpage and mention your results.




The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 07:38


Yes, great result on the tetralin! Someone might want to try that on the sodium!

[Edited on 30-12-2010 by blogfast25]
View user's profile Visit user's homepage View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 07:42


Quote: Originally posted by bahamuth  
I am interested if anyone tried this?


Quote: Originally posted by Jor  
Now this would be a very interesting way to make lithium, but it's really a bummer that lithium has such a low molecular weight, making it impossible to make acceptable amounts of lithium.


Also, a little off topic though,may LiOH be collected/synthesized from worn out Li ion laptop batteries?
This may be a cheap source for Li compounds...




The patent doesn't mention it. Most people will be deterred, perhaps unnecessarily, by the high reduction potential of Li+ (about 3 V)... And Li alkanoates are likely to be even less soluble in alkanes/naphtenics. But it's worth a try. We're probably more interested in making the more commonly used sodium, though...

[Edited on 30-12-2010 by blogfast25]
View user's profile Visit user's homepage View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 07:52


Quote: Originally posted by len2  
The reason the reaction goes slow in heavy paraffins is that the alkoxides are not very soluble in them - even the t-alcohol doesnt dissolve all that easily. The aromatic gets around that problem.



len1: can you substantiate the claimed higher solubility of alkoxides in aromatics? We’re looking into improving that solubility for sodium alkoxides from the alcohol angle (see organics section) but the solvent may prove more important...
View user's profile Visit user's homepage View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 08:52


4 l reagent grade Tetralin ® from Sigma-Aldrich: £115.8

http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en...

Ding dong!
View user's profile Visit user's homepage View All Posts By User
DJF90
International Hazard
*****




Posts: 2266
Registered: 15-12-2007
Location: At the bench
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 10:01


4 consecutive posts in under 80 minutes. No wonder this thread is 22 pages long...
View user's profile View All Posts By User
NurdRage
Hazard to Others
***




Posts: 182
Registered: 11-11-2010
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 17:03


Quote: Originally posted by DJF90  
4 consecutive posts in under 80 minutes. No wonder this thread is 22 pages long...


I agree, the edit button as well as divider lines should be used more often.

Like i am about to do:
===========================================

@ everyone else

More negative results:

Making sodium does not work in tetralin using t-amyl alcohol as the catalyst. So much for that idea.
View user's profile View All Posts By User
tnphysics
Harmless
*




Posts: 18
Registered: 29-12-2010
Member Is Offline

Mood: No Mood

[*] posted on 30-12-2010 at 18:59


As for napthalene-you might get napthalides.

What about heavier alcohols?

As for making Na and Li, I would try making them by using K to displace from the chlorides. They are

Anyone tried Al lately?




I LOVE science!
View user's profile View All Posts By User
mr.crow
International Hazard
*****




Posts: 884
Registered: 9-9-2009
Location: Canada
Member Is Offline

Mood: 0xFF

[*] posted on 30-12-2010 at 19:31


Nurd, you are a chemistry hero. Of course having a real lab helps!

Tetralin is a trademark of Sigma Aldrich, you can find it other places as Tetrahydronaphthalene. One of those annoying peroxide formers >: ( Why is this? The benzylic carbon is extra reactive?




Double, double toil and trouble; Fire burn, and caldron bubble
View user's profile View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 31-12-2010 at 07:32


Quote: Originally posted by NurdRage  
Quote: Originally posted by DJF90  
4 consecutive posts in under 80 minutes. No wonder this thread is 22 pages long...


I agree, the edit button as well as divider lines should be used more often.

Like i am about to do:
===========================================

@ everyone else

More negative results:

Making sodium does not work in tetralin using t-amyl alcohol as the catalyst. So much for that idea.


I don't think making multiple comments makes much difference. Within reason people should be free to make as many comments as they see fit/need.

Re. the sodium, how long did you 'cook' for Nurdy?





===========================================

Quote: Originally posted by tnphysics  
What about heavier alcohols?

As for making Na and Li, I would try making them by using K to displace from the chlorides. They are

Anyone tried Al lately?


Read the tread. There's now a 'longer chain t-alcohols' thread opened for that purpose in the ORGANICS SECTION.

Displacing Li and K with Na doesn't work thermodynamically, as explained at length elsewhere. Search...


EDIT(by woelen): Merged double posts

[Edited on 1-1-11 by woelen]
View user's profile Visit user's homepage View All Posts By User
Arthur Dent
International Hazard
*****




Posts: 546
Registered: 22-10-2010
Member Is Offline

Mood: entropic

[*] posted on 31-12-2010 at 11:48


This morning, as I was doing some shopping at the drugstore, I saw a bottle of lamp oil on a shelf that featured as its principal ingredient "99% Pure liquid Paraffin" stating further that it's odorless and smokeless. I can attest that it is totally odorless. I'll try to do a "dry run" just to see what the boiling point of that stuff is.

It's distributed by Lembex Import and the product is called "DecoFlam". Website has little technical data on the product and I doubt i'll be able to track down a MSDS, but this "oil" looks promising.

http://www.alibaba.com/product/lembex-11540374-10973924/Pure...

Robert


[Edited on 31-12-2010 by Arthur Dent]

[Edited on 31-12-2010 by Arthur Dent]
View user's profile View All Posts By User
Eclectic
International Hazard
*****




Posts: 899
Registered: 14-11-2004
Member Is Offline

Mood: Obsessive

[*] posted on 31-12-2010 at 12:35


I got the Ritchie Compass filling fluid URLed in my last post above, and it is in fact Isopar L, and totally odorless.

http://www.westmarine.com/webapp/wcs/stores/servlet/Product_...

http://exxonmobilchemical.ides.com/en-US/ds128997/Isopar%E2%...



[Edited on 12-31-2010 by Eclectic]
View user's profile View All Posts By User
smuv
International Hazard
*****




Posts: 842
Registered: 2-5-2007
Member Is Offline

Mood: Jingoistic

[*] posted on 31-12-2010 at 13:35


The good thing about aromatic solvents, is that while they are non-polar, they have a great degree of polarizability. This allows aromatics to be better solvents for polar compounds than similar non-aromatic solvents. For example, methanol is miscible with benzene, however not with cyclohexane (though it is very soluble in cyclohexane).

Take home message: alkoxides are probably more soluble in aromatics than parafins (or non-aromatic olefins).
View user's profile View All Posts By User
starch
Harmless
*




Posts: 33
Registered: 13-3-2010
Member Is Offline

Mood: No Mood

[*] posted on 31-12-2010 at 18:03


wow guys this thread is awsome

Excellent discusion, Excellent experimentals, and Excellent results :)

not something im going try ne time soon but still im in awe :cool:

well done to all those with shiney balls of K

cant wait to read more

take care mad scientists

View user's profile View All Posts By User
len1
International Hazard
*****




Posts: 595
Registered: 1-3-2007
Member Is Offline

Mood: NZ 1 (goal) - Italy 1 (dive)

[*] posted on 31-12-2010 at 22:53


I meant of course structure of surface of solid potassium obtained this way, not molten potassium (??)

Smuv wrote very nicely about aromatics, I couldnt have done it better myself. Except to add that I expect solubility in long straight chain paraffins to be less than in shorter chains, because of very different molecular shapes

[Edited on 1-1-2011 by len1]
View user's profile View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 1-1-2011 at 09:01


len1: with regards to the aromatics, can we conclude that higher solubility caused (or at least contributed) to the better result with Tetralin? That would stillnot explain the poor result for Tetralin/Na of course...

Perhaps we should be looking at t-alcohols with aromatic functionality, 'smuv' is making some interesting noises along those lines in the t-alcohols thread ('organics')...
View user's profile Visit user's homepage View All Posts By User
woelen
Super Administrator
Thread Pruned
1-1-2011 at 14:49
woelen
Super Administrator
*********




Posts: 7722
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 1-1-2011 at 14:50


Merged double posts and tidied up a little.



The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
tnphysics
Harmless
*




Posts: 18
Registered: 29-12-2010
Member Is Offline

Mood: No Mood

[*] posted on 1-1-2011 at 17:08


Quote: Originally posted by blogfast25  
Quote: Originally posted by NurdRage  
Quote: Originally posted by DJF90  
4 consecutive posts in under 80 minutes. No wonder this thread is 22 pages long...


I agree, the edit button as well as divider lines should be used more often.

Like i am about to do:
===========================================

@ everyone else

More negative results:

Making sodium does not work in tetralin using t-amyl alcohol as the catalyst. So much for that idea.


I don't think making multiple comments makes much difference. Within reason people should be free to make as many comments as they see fit/need.

Re. the sodium, how long did you 'cook' for Nurdy?





===========================================

Quote: Originally posted by tnphysics  
What about heavier alcohols?

As for making Na and Li, I would try making them by using K to displace from the chlorides. They are

Anyone tried Al lately?


Read the tread. There's now a 'longer chain t-alcohols' thread opened for that purpose in the ORGANICS SECTION.

Displacing Li and K with Na doesn't work thermodynamically, as explained at length elsewhere. Search...


EDIT(by woelen): Merged double posts

[Edited on 1-1-11 by woelen]


meant K + NaCl -> KCl + Na etc.




I LOVE science!
View user's profile View All Posts By User
blogfast25
Thought-provoking Teacher
*****




Posts: 10340
Registered: 3-2-2008
Location: Old Blighty
Member Is Offline

Mood: No Mood

[*] posted on 2-1-2011 at 06:52


Quote: Originally posted by tnphysics  
meant K + NaCl -> KCl + Na etc.


Yep. I know. Still doesn't work...

[Edited on 2-1-2011 by blogfast25]
View user's profile Visit user's homepage View All Posts By User
garage chemist
chemical wizard
*****




Posts: 1803
Registered: 16-8-2004
Location: Germany
Member Is Offline

Mood: No Mood

[*] posted on 4-1-2011 at 14:51


Today I finally have the chance to try this, as the supplier first sent me the wrong kind of Shellsol and then closed down over christmas and New Years. Now the Shellsol D70 arrived and I started a batch according to Pok's original procedure.

I used 3g of fine reagent grade magnesium powder (I don't have any filings), 6g of KOH flakes and 0,6g of t-Butanol.
40ml of the solvent, KOH and Mg were combined and heated over a free flame. Not even a minute after starting to heat (the solvent was barely warm), the mixture suddenly violently reacted, evolving a large amount of gas and white smoke!
There was visible "fire" under the solvent, as part of the KOH and magnesium apparently reacted in a thermite-like reaction.
Perhaps fine Mg powder wasn't the right thing to use... but I have no turnings, so I'll have to live with this for now.
I heated to a boil, and added the t-BuOH mixed with 10ml Shellsol over ca. 20 minutes.
It's currently refluxing. Tiny globules of K seem to form, but they're not coalescing as far as I can see. I'll report how it looks after 4 hours of reflux. There's still a large amount of unreacted Mg powder.

What's very annoying is that evaporated t-BuOH is solidifying on the cooling coil of the dimroth condenser. A large crystal crust is forming there.
I use very cold water in the condenser to keep the volatile t-BuOH from getting lost, but that's not how I meant it to be.
There isn't sufficient Shellsol evaporating to wash down the solid t-BuOH.
Did someone encounter this problem as well?







www.versuchschemie.de
Das aktivste deutsche Chemieforum!
View user's profile View All Posts By User
NurdRage
Hazard to Others
***




Posts: 182
Registered: 11-11-2010
Member Is Offline

Mood: No Mood

[*] posted on 4-1-2011 at 14:56


Yeah, this is why i eventually moved competely to t-amyl alcohol which has a lower melting point than t-butanol.

For the times i did t-butanol i just turned off the cooling water for a few minutes and let the t-butanol melt back down before restarting it again. It was crude but it worked for me.

I think some experimentors just blow air straight into the condesor instead of cold water.
View user's profile View All Posts By User
 Pages:  1  ..  20    22    24  ..  66

  Go To Top