| Pages:
1
..
8
9
10
11
12
..
14 |
karlos³
International Hazard
Posts: 1520
Registered: 10-1-2011
Location: yes!
Member Is Offline
Mood: oxazolidinic 8)
|
|
My stirrers heating broke down(loose contact) and I tried to fix it...without being good or even skilled with technic stuff but more like my hands
growing out of my ass, and the inevitable happened, I failed to put it together and don't want to try it myself in the fear of irreversible damaging
it.
But I had a reaction to run, a ring closure/amidation for thalidomide, and simply tried it on the hotplate with four little stirbars as sort of
boiling chips and as a help when swirling manually.
Worked as expected, surprisingly, even slightly better than the last time!
Encouraged by this, I spontanously made an experiment under the same conditions, except with oleic acid as substrate, to produce oleamide.
Worked fine too!
That felt a bit archaic, observing everything with hawkeyes throughout the reaction(only 45min each), but I am proud to be able to improvise , with
insufficient equipment and all, and that without being affected negatively, or even at all by this drawback 
But I already look forward to get back to my the pet-project(s) when a stirrer is on hand... those two amidations were just a poor substitute for it,
but at least I could still do a little bit of the simple lab work.
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
fractional distillation of EtOH. notice the SM patch......
"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
|
|
|
ChemTalk
Hazard to Self
Posts: 65
Registered: 13-12-2018
Location: United States
Member Is Offline
Mood: colloidal
|
|
I keep noticing the nice periodic table.
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
Success!!! CaO. Roasted pickling lime at a red heat for an hour. Put a couple grams in a piece of foil and dripped water on it, and it proceeded to
get HOT and sizzle. YAY. 99% EtOH here I come!!!
"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
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
Broke the EtOH and H2O Azeoterope, yippee!!
Had a terrible recovery, but don't care, I broke the ^&^%&*$ azeotrope!!!
Been an obsession.....
50 gms CaO and 250ml of 95% EtOH were refluxed for five hours, then allowed to sit for 8. I kept my moisture discipline up (drying tubes, quick
stoppering, oven dried glass), and when I distilled the mixture I got 70mls that read about 98-99 on my hydrometer (my house just happened to be 20C
inside, no temperature corrections necessary).
Procedure from Vogel's Third.
"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
|
|
|
Sulaiman
International Hazard
Posts: 3692
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
What happened to my potassium permanganate ?
Some re-crystallised potassium permanganate
I left the KMnO4 crystals exposed to air for a couple of weeks,
in the cupboard where I keep glassware and solid chemicals in 'sealed' containers - no liquids,
and found this
what happened ? what are the white crystals ?
(the most volatile substances in the cupboard are;
ammonium bicarbonate, TCCA, sodium metabisulphite
... all kept in glass bottles)
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
Unknown metal oxide
Wasn't my intent, but when melting some white metal the other night I inadvertently got some (X)O. Opened the front of my furnace and there was what
looked like and actual flame coming off the crucible content.
"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
|
|
|
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Testing to see if posting to this thread works...
|
|
|
Piroz
Harmless
Posts: 19
Registered: 15-12-2020
Location: Poland
Member Is Offline
|
|
I used my furnance to preparation calcium oxide from old, carbonated slaked lime. I need CaO for preaparation both ammonia and calcium nitrate.
https://youtu.be/d6vDtND4HSU
|
|
|
Bedlasky
International Hazard
Posts: 1239
Registered: 15-4-2019
Location: Period 5, group 6
Member Is Offline
Mood: Volatile
|
|
Currently waiting for crystals of copper(II) tris complexes - specifically [Cu(H-1tris)2(H2O)] and
[Cu(tris)4](ClO4)2. The latter one should be energetic.
|
|
|
j_sum1
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
Did some titration with my son. Just for the fun of it.
Tried out a few different indicators. And he got to play with some precise measuring equipment.
|
|
|
ChemTalk
Hazard to Self
Posts: 65
Registered: 13-12-2018
Location: United States
Member Is Offline
Mood: colloidal
|
|
Quote: Originally posted by j_sum1  | Did some titration with my son. Just for the fun of it.
Tried out a few different indicators. And he got to play with some precise measuring equipment.
|
Oh, that's awesome, sounds like fun. My son might do some chemistry this weekend also.
|
|
|
njl
National Hazard
Posts: 609
Registered: 26-11-2019
Location: under the sycamore tree
Member Is Offline
Mood: ambivalent
|
|
What the heck is the difference between diazomethane and methane diazonium salt? Other than the obvious structural difference. How do their
reactivities compare? One review says they're completely different and yet another implies they are interchangeable. Can diazonium compounds eliminate
H+ to form a diazo compound?
Reflux condenser?? I barely know her!
|
|
|
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Diazomethane is a highly unstable and reactive gas, but it is still isolable and finds a lot of use in synthesis. The methyldiazonium ion makes it
looks tame by comparison. It is so unstable that it is only observed transiently. Aliphatic diazonium salts are generally far too reactive to be
synthetically useful or safe, while aryl diazonium salts are significantly more stable. In the future, please cite these “reviews” that you speak
of. I don’t know why anyone would say that the two species are equivalent. Perhaps they exist in equilibrium, under certain conditions, but they are
not the same thing.
|
|
|
Piroz
Harmless
Posts: 19
Registered: 15-12-2020
Location: Poland
Member Is Offline
|
|
Finally I got potassium chloride from wood ashes practically free from sodium compounds. I used crystallisation from saturated hot solution in plastic
bottle (>50 deg. C), sodium was removed in crystalline mass, leaved potassium chloride in the solution. However crystallisation from cold solution
(several times) wasn't enough to remove some sodium.
Flame analysis suprised me, potassium chloride from chem store reffered as 99% purity have more sodium than my potassium chloride from wood ashes.
   
[Edited on 8-3-2021 by Piroz]
|
|
|
j_sum1
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Offline
Mood: Most of the ducks are in a row
|
|
Nice work, Piroz.
|
|
|
njl
National Hazard
Posts: 609
Registered: 26-11-2019
Location: under the sycamore tree
Member Is Offline
Mood: ambivalent
|
|
Is there a conclusion one can draw from that?
Reflux condenser?? I barely know her!
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
Yes, from the flame colors. Takes barely any Na ions to color a flame yellow. The hot xtallized KCl is a lovely violet.
*edit* Conclusion being that his own work-up had a much better flame color. obviously violet, unlike the commercial. Hence his contained less Na ion.
[Edited on 3-9-2021 by arkoma]
"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
|
|
|
Bezaleel
Hazard to Others
Posts: 444
Registered: 28-2-2009
Member Is Offline
Mood: transitional
|
|
Good job, Piroz!
|
|
|
Elemental Phosphorus
Hazard to Others
Posts: 185
Registered: 11-11-2016
Location: Is everything
Member Is Offline
Mood: No Mood
|
|
I just did a little extraction of capsaicin from dried habaneros, hope to do it on a larger scale this week, but it was just a small scale run.
Wish I had a soxhlet extractor to use, but I just used boiling acetone in a flask and then poured it off and evaporated. Final product was a little
bit of orange oil, and of course I had to taste a tiny bit, so I just put a knife tip in it and tasted it and it was definitely spicy (I know it’s
not best practice, but I had to try).
Also did woelen’s demonstration with the oxidation states of vanadium, since I had some V2O5 laying around.
  
|
|
|
arkoma
Redneck Overlord
Posts: 1761
Registered: 3-2-2014
Location: On a Big Blue Marble hurtling through space
Member Is Offline
Mood: украї́нська
|
|
i've only used my soxhlet a few times, but it is dang sure a cool piece of gear. seems like it was <$30US from nanshinglass
"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
|
|
|
Bezaleel
Hazard to Others
Posts: 444
Registered: 28-2-2009
Member Is Offline
Mood: transitional
|
|
Vacuum setup repairs
The rotary vane pump I use is not really suited for pumping on liquids which give off corrosive fumes. Obviously, if you ignore that, then your setup
will degrade over time. I took apart several joints of the type shown in the picture.
On the majority of the flanges, there was corrosion, revealing itself as white powdery crusts. Typically, the components shown are made of aluminium,
which is a really bad choice for components used in a corrosive environment. (But who would dare to complain when you receive all of this for free?)
Anyway, there are two points of interest:
* For one joint I did not have a spacer when I received the vacuum components, and I made one from PTFE on a lathe (shown in the photo). The
connection which had this spacer was much less corroded than the joints which have aluminium spacers.
* I polished the flanges with a household grinding pad and some household grinding/polishing powder, washed it and let everything dry over night. I
re-assembled it the other day using a very small amount of silicone vacuum grease on the flanges and the O-rings.
When I pulled a vacuum I was disappointed to stay at 10 mBar of pressure, but after the system had dried for another day, it rapidly went down to the
limit of my pressure gauge. So apparently, it was due to droplets of water which were evaporating that the pressure initially stayed at 10mBar.
|
|
|
njl
National Hazard
Posts: 609
Registered: 26-11-2019
Location: under the sycamore tree
Member Is Offline
Mood: ambivalent
|
|
How will the basicity of sodium isopropoxide compare to that of sodium methoxide in the claisen condensation, and how might that effect the reaction
outcome? I can't find anything detailing NaOiPr properties.
Reflux condenser?? I barely know her!
|
|
|
DraconicAcid
International Hazard
Posts: 4332
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
| Quote: Originally posted by njl | | How will the basicity of sodium isopropoxide compare to that of sodium methoxide in the claisen condensation, and how might that effect the reaction
outcome? I can't find anything detailing NaOiPr properties. |
I would expect it to be slightly more basic, but suitable.
PS- anyone know if magnesium alkoxides would work in that reaction? I've got far more magnesium than sodium.....
[Edited on 18-3-2021 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.
|
|
|
njl
National Hazard
Posts: 609
Registered: 26-11-2019
Location: under the sycamore tree
Member Is Offline
Mood: ambivalent
|
|
Yes, I believe even MgO can be used to form the basic species.
Reflux condenser?? I barely know her!
|
|
|
| Pages:
1
..
8
9
10
11
12
..
14 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
