| Pages:
1
..
58
59
60
61
62
..
104 |
madscience
Banned
Posts: 24
Registered: 5-7-2016
Member Is Offline
Mood: No Mood
|
|
acetol from sugar
how would you synthesis acetol from sugar
|
|
|
Texium
|
Threads Merged
5-7-2016 at 17:40 |
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
Depends what sugar...
If normal table sugar; then if by acetol, you mean hydroxyaceton (1-hydroxy-propanone) ...
you may get a chance to go there from:
1)sugar alcoholic fermentation --> ethanol -oxydation-> acetic acid
2)sugar acetic fermentation --> acetic acid
3)making aceton from acetic acid (Ca acetate or Ba acetate pyrolysis...CaCO3 or BaCO3 recoverable and recycled with acetic acid)
4) sugar fermentation direct to aceton
5) aceton monohalogenation (Cl2 or Br2 in HCl or HBr) beware of the lachrymatory product (a wargas)--> Under the Hood
6) hydrolysis in neutral media to avoid as much polycondensation into resinous polyphénols
Not chemistry for a beginner!
Much easier to start directly from aceton...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Online
Mood: PhD candidate!
|
|
I have an emulsion of water and isobutyl bromide. What would be the best way to break it up? I was thinking of adding some salt or sulfuric acid, but
I don't want to screw it up.
Side question: Does anyone know what isobutyl bromide smells like? I can't find any description of it, but my product smells butterscotch-like, kind
of along the lines of MEK but heavier and sweeter.
Edit: Never mind the thing about the emulsion, it cleared itself up after resting for a few minutes.
[Edited on 7-10-2016 by zts16]
|
|
|
Refinery
Hazard to Others
Posts: 371
Registered: 17-2-2014
Member Is Offline
Mood: Still
|
|
Can 2% MEK in ethanol be polymerized or otherwise converted to a more stable form for ethanol purification with NaOH?
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
Quote: Originally posted by Refinery  | | Can 2% MEK in ethanol be polymerized or otherwise converted to a more stable form for ethanol purification with NaOH? |
Might work!
Butanone (MEK) may be subject to aldolisation-crotonisation thus yielding higher molecular weight molecules, less volatile and remaining in the flask
with the NaOH during the distillation of Ethanol.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
Refinery
Hazard to Others
Posts: 371
Registered: 17-2-2014
Member Is Offline
Mood: Still
|
|
Only way to find it out is to test it, then.
|
|
|
dawsonsuen
Harmless
Posts: 29
Registered: 26-7-2015
Member Is Offline
Mood: Complexed
|
|
Haloform Reaction Question.
Greetings,
I carried out a haloform reaction between a solution of 5% sodium hypochlorite and acetone earlier today and I only used a 5% excess of bleach. Unlike
my previous run that has a very pale greenish yellow, the end solution of this run was completely colourless. Hence I was wondering if it would be
useful if I mix all my chloroform into 1L of bleach just to ensure all acetone has reacted and to avoid having to deal with the annoying azeotrope
between acetone and chloroform before distilling my chloroform.
Thanks in advance!
Long story short, Chem is try!
|
|
|
Texium
|
Threads Merged
11-7-2016 at 07:47 |
madscience
Banned
Posts: 24
Registered: 5-7-2016
Member Is Offline
Mood: No Mood
|
|
leuckart reaction and formate salts
Would the salt of formic acid work in the leuckart reaction like sodium formate and potassium formate, and would it reduce the imine if you react
aldehyde or ketone with a amine with formate salt as the reducing agent and would still form the n formyl impurities the reason I ask im trying to
make alanine
[Edited on 19-7-2016 by madscience]
|
|
|
CRUSTY
Hazard to Others
Posts: 139
Registered: 5-6-2016
Location: Nearby
Member Is Offline
Mood: High-Order
|
|
No. The use of ammonium formate is critical for the synthesis of an amine. Without the ammonium cation, it is impossible to form the hemiaminal which
is reduced to the final amine product. By the way, could you elaborate on what you mean by "reduce impurities"? What sort of impurities are you
referring to?
|
|
|
Texium
|
Threads Merged
19-7-2016 at 12:56 |
Ba(ClO3)2
Harmless
Posts: 33
Registered: 30-4-2016
Member Is Offline
Mood: No Mood
|
|
Test for guanidine nitrate
We made some (hopefully) guanidine nitrate by following the procedure in this thread http://www.sciencemadness.org/talk/viewthread.php?tid=12938
Things got a bit out of hand near the end, so we're not sure If we actually have guanidine nitrate. Here's what we've got:
![IMG_3257[1].JPG - 2.3MB](http://www.sciencemadness.org/talk/files.php?pid=455385&aid=52078)
Is there any test for guanidine nitrate that would distinguish it from ammonium nitrate and urea?
|
|
|
j_sum1
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Online
Mood: Most of the ducks are in a row
|
|
Question – Is it really a catalyst?
I have been thinking about a couple of well-known reactions.
First, Fischer esterification in which the added H2SO4 is often stated to be a catalyst. I am questioning this. It seems to me that its role is to
push the equilibrium to the right rather than to catalyse. Sulfuric acid provides for an acidic environment and also absorbs water: both of which
favour the formation of products. Is there any catalysis occurring also?
Second, the lovely Chameleon reaction demonstration of the oxidation states of manganese using (typically) sucrose. NaOH is added, purportedly as a
catalyst. But it seems a strange chemical for a catalyst in my limited experience. And I cannot really figure out what its role is. I'd love some
enlightenment.
(I bet blogfast25 knows. But we have seen less of him lately.)
|
|
|
AvBaeyer
National Hazard
Posts: 651
Registered: 25-2-2014
Location: CA
Member Is Offline
Mood: No Mood
|
|
j-sum1:
Sulfuric acid is a catalyst in the Fischer esterification. It is chemically unchanged in the reaction. With some effort, you could isolate all of the
H2SO4 that you started with at the end of the reaction which by definition makes it a catalyst. Mechanistically, the H2SO4 reacts with the carboxylic
acid function to form a transient acylium ion which reacts with the alcohol to form the ester via a follow-on elimination of water. No water is
"absorbed." Any good O-chem book should illustrate this mechanism.
AvB
|
|
|
j_sum1
Administrator
Posts: 6320
Registered: 4-10-2014
Location: At home
Member Is Online
Mood: Most of the ducks are in a row
|
|
| Quote: Originally posted by AvBaeyer | j-sum1:
Sulfuric acid is a catalyst in the Fischer esterification. It is chemically unchanged in the reaction. With some effort, you could isolate all of the
H2SO4 that you started with at the end of the reaction which by definition makes it a catalyst. Mechanistically, the H2SO4 reacts with the carboxylic
acid function to form a transient acylium ion which reacts with the alcohol to form the ester via a follow-on elimination of water. No water is
"absorbed." Any good O-chem book should illustrate this mechanism.
AvB |
Thanks AvB.
I am yet to read a good O-Chem book. Long story.
So what is happening with the NaOH and the Mn reduction?
|
|
|
stoichiometric_steve
National Hazard
Posts: 827
Registered: 14-12-2005
Member Is Offline
Mood: satyric
|
|
Can i dissolve Palladium powder in HCl (>30%) / H2O2 (~30%) to make PdCl2?
|
|
|
Ramium
Hazard to Others
Posts: 144
Registered: 3-12-2014
Location: new zealand
Member Is Offline
Mood: Licit fish
|
|
copper-glycerol complex
I made this complex https://upload.wikimedia.org/wikipedia/commons/0/00/Glycerol...
I added some glycerol to a suspension of copper(ii) hydroxide in dilute sodium hydroxide solution and ended up with a beautiful solution of the
complex.
My question is, how can I isolate the complex from this solution?
Will adding ethanol make the complex precipitate?
insoluble in society
|
|
|
madscience
Banned
Posts: 24
Registered: 5-7-2016
Member Is Offline
Mood: No Mood
|
|
which functional group would aminate first
which of this functional groups would aminate first a benzoyl or an acetyl group if you do a reductive amination on these groups
|
|
|
Texium
|
Threads Merged
21-7-2016 at 12:52 |
The Volatile Chemist
International Hazard
Posts: 1981
Registered: 22-3-2014
Location: 'Stil' in the lab...
Member Is Offline
Mood: Copious
|
|
| Quote: Originally posted by dawsonsuen | Greetings,
I carried out a haloform reaction between a solution of 5% sodium hypochlorite and acetone earlier today and I only used a 5% excess of bleach. Unlike
my previous run that has a very pale greenish yellow, the end solution of this run was completely colourless. Hence I was wondering if it would be
useful if I mix all my chloroform into 1L of bleach just to ensure all acetone has reacted and to avoid having to deal with the annoying azeotrope
between acetone and chloroform before distilling my chloroform.
Thanks in advance! |
From what I recall, the reaction runs various colors based on bleach quality/source. Watch chemplayer's synthesis of chlorobutanol to see if the
reaction ran more like that preparation and the chlorobutanol sideproduct was formed due to excess acetone.
|
|
|
RogueRose
International Hazard
Posts: 1592
Registered: 16-6-2014
Member Is Offline
|
|
Distillation setup - 500ml vs 1L - can they be interchanged with vessel size?
I see 500ml and 1L setups advertised and price may be double for the 1L. Are general distillation (no columns - just boiling flask, riser from flask,
condenser & receiving vessel) setups capable of just changing the vessel size but still using the same condenser and riser (assuming same joint
size)?
|
|
|
CharlieA
National Hazard
Posts: 646
Registered: 11-8-2015
Location: Missouri, USA
Member Is Offline
Mood: No Mood
|
|
Yes
|
|
|
Texium
|
Threads Merged
23-7-2016 at 21:09 |
RogueRose
International Hazard
Posts: 1592
Registered: 16-6-2014
Member Is Offline
|
|
MonoAmmonium Phosphate vs DiAmmonium Phosphate as yeast nutrient/energizer
I have seen a lot of yeast nutrients/energizers that contain DAP and I have also seen some that have ammonium sulfate in place of DAP. From what I
have read the reason for putting these in with the yeast is to provide nitrogen to the yeast. My question is whether MAP can be used instead of DAP
(with adjustments for the fact MAP has 1/2 the N as DAP). Also is there any reason that DAP is better than ammonium sulfate?
|
|
|
Texium
|
Threads Merged
24-7-2016 at 20:24 |
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
| Quote: Originally posted by j_sum1 |
Second, the lovely Chameleon reaction demonstration of the oxidation states of manganese using (typically) sucrose. NaOH is added, purportedly as a
catalyst. But it seems a strange chemical for a catalyst in my limited experience. And I cannot really figure out what its role is. I'd love some
enlightenment.
|
It is an oxydoredox reaction as such the results depends on the pH, some reactions occurs into acidic media (H(+)) and others into basic media
(OH(-))...see oxydoredox tables.
The reducer is the sucrose ...aldehyd turned into carboxylic and polyols turned into keto groups and further cleaved into oxalic acid and carbonic
acid.
The oxydiser is the purple permanganate anion (MnO4(-)) turning into green manganate anion (MnO4(2-)) and then further into pale pink manganous cation
(Mn(2+)).
So oxydation state of Mn goes from +7 to +6 to +2.
The H(+) or OH(-) are recovered from the water solvent.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
Probably not with ethanol that will be a competitive complexator to 1,2,3-propantriol...maybe try adding some diethylether.
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
| Quote: Originally posted by RogueRose | | I have seen a lot of yeast nutrients/energizers that contain DAP and I have also seen some that have ammonium sulfate in place of DAP. From what I
have read the reason for putting these in with the yeast is to provide nitrogen to the yeast. My question is whether MAP can be used instead of DAP
(with adjustments for the fact MAP has 1/2 the N as DAP). Also is there any reason that DAP is better than ammonium sulfate? |
Also pH addaptation because the trimming effect on pH will not be the same from MAP vs DAP...and of course the osmotic pressure...
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
DraconicAcid
International Hazard
Posts: 4332
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
Ethanol will be monodentate, and unlikely to compete with the chelating gylerol.
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.
|
|
|
madscience
Banned
Posts: 24
Registered: 5-7-2016
Member Is Offline
Mood: No Mood
|
|
palladium alternate
whats a good alternative to palladium acetate
|
|
|
Texium
|
Threads Merged
26-7-2016 at 09:45 |
| Pages:
1
..
58
59
60
61
62
..
104 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
