| Pages:
1
..
73
74
75
76
77
..
104 |
RogueRose
International Hazard
Posts: 1592
Registered: 16-6-2014
Member Is Offline
|
|
Acetic Acid from Sodium acetate/diacetate
I was looking at the procedure of mixing H2SO4 and CH3CO2Na (sodium acetate) and was wondering if sodium diacetate could be used NaH(CH3CO2)2. The
equations I've come up with are as follows:
Sodium acetate + sulfuric acid
2(CH3CO2Na) + H2SO4 = 2(CH3COOH) +Na2SO4
Sodium acetate + sulfuric acid
NaH(CH3CO2)2 + H2SO4 = 2(CH3CO2H) + NaHSO4
So with the diacetate the result would be sodium bisulfate which may be more useful for some than sodium sulfate. Now I'm not sure how soluble
NaHSO4 would be in acetic acid or if it would push a reaction back towards sulfuric acid - both would be good reasons this isn't used but I figured it
would be worth knowing.
|
|
|
clearly_not_atara
International Hazard
Posts: 2786
Registered: 3-11-2013
Member Is Offline
Mood: Big
|
|
I think the product will in all cases depend on the stoichiometry of H2SO4 vs Na+. I am also pretty sure you want to distill acetic acid off.
I think you can convert it to the calcium salt somehow? Not sure.
EDIT: Combining hot concentrated aqueous solutions of calcium chloride and sodium acetate precipitates calcium acetate in about 50% yield, judging by
solubity tables.
[Edited on 14-6-2017 by clearly_not_atara]
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Can you store acetone in HDPE wash bottles, or will it evaporate?
|
|
|
tsathoggua1
Hazard to Others
Posts: 335
Registered: 8-1-2017
Location: Beyond the pale
Member Is Offline
Mood: Phosphorescent
|
|
Out of methyl carbonate, ethylene carbonate and propylene carbonate, which is preferable for the purpose of production of small quantities of alkali
metals via electrolysis?
Thing is, I have a reasonable sized quantity of Na, but its in the form of one large brick, hermetically vacuum-packed and heat-sealed in an inner,
thick plastic liner filled with mineral oil which itself is inside a hermetically sealed bag full of inert gas. I'd sooner make a little and not have
to open it, due to shelf-life considerations, I don't need the entire 100g brick right this moment, only maybe 15g or so, so it makes more sense to
try electrolysis in one of the carbonate esters of hydroxide, and in any case its something I've wanted to add to my solvent arsenal for a while.
If that doesn't produce the desired results, I'll go with Nurdrage's excellent looking method of thermiting NaOH or KOH using magnesium dust, grinding
up the slag in a blender (only variation, backfilling this with an argon purge first and grinding it under positive pressure of Ar. Might have to
tweak the bender a little bit but its only ever been me that uses the thing so no loss there), and then separating the sodium out using 1,4-dioxane
prepared by the sulfuric acid dehydration of ethylene glycol, which I have plenty of, as I do of concentrated H2SO4. I just don't want to open the Na
brick I already have since it won't have an indefinite shelf life, and there is perhaps 15g or so of a ketoxime awaiting preparation so as to be
reduced to the corresponding amine with Na/alcohol.
|
|
|
Sulaiman
International Hazard
Posts: 3692
Registered: 8-2-2015
Location: 3rd rock from the sun
Member Is Offline
|
|
Acetone, b.p. 56oC
so you can store it in an hdpe wash bottle, until it evaporates away 
I find hdpe bottles with hdpe:hdpe sealed bottle caps ok for acetone starage with negligible loss due to evaporation.
CAUTION : Hobby Chemist, not Professional or even Amateur
|
|
|
tsathoggua1
Hazard to Others
Posts: 335
Registered: 8-1-2017
Location: Beyond the pale
Member Is Offline
Mood: Phosphorescent
|
|
I'd expect the result of destructive distillation performed on the Ca salt to be acetone rather than CH3COOH, that is a known route to P2P, albeit
not one optimized for yields, pyrolysis of either the Ca or Pb salt of phenylacetic acid results in dehydration to the ketone, not liberation of the
acid. H2SO4 is a fairly strong dehydrating agent itself when concentrated, so I could see either formation of acetone, or perhaps dehydration and
elimination to ethene (or worse, ketene, although granted that would make acetic acid if put to use, but its dreadfully toxic stuff)
[Edited on 14-6-2017 by tsathoggua1]
|
|
|
Texium
Administrator
Posts: 4580
Registered: 11-1-2014
Location: Salt Lake City
Member Is Offline
Mood: PhD candidate!
|
|
Ignoring tsathoggua's usual cruddy, off-topic, drug chem laced post, yes, you should definitely be able to distill a mixture of sulfuric acid and
sodium diacetate to get acetic acid. There would be no reason to convert it to the calcium salt. You do have to distill though. Don't count on getting
it to work otherwise.
|
|
|
Texium
|
Threads Merged
14-6-2017 at 08:01 |
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Quote: Originally posted by Sulaiman  |
Acetone, b.p. 56oC
so you can store it in an hdpe wash bottle, until it evaporates away
I find hdpe bottles with hdpe:hdpe sealed bottle caps ok for acetone starage with negligible loss due to evaporation. |
I don't have any sealed caps for my HDPE wash bottles. I wonder if it is still OK to store acetone in them....
|
|
|
Geocachmaster
Hazard to Others
Posts: 146
Registered: 5-3-2016
Location: Maine, USA
Member Is Offline
Mood: Corroded, just like my spatulas
|
|
What kind of wash bottle is it? I have two, one has the spout through the lid, the other through the side. The one which comes out the side has a cap
that lets air in (not sure why, they didn't want air bubbling through I guess). In the former case I think a bunch of PTFE tape would seal it well! As
for the latter option I'm not sure.
Edit: the surface area of acetone that is exposed though the "straw" is probably not significant. That would be the only way for acetone to escape.
[Edited on 6/14/2017 by Geocachmaster]
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
The straw on my wash bottles actually goes through the cap. They are about 1/10 the cost of the wash bottles with the straw at the side, and I see
very little difference in function....
I guess I'll try filling one with some acetone and see what happens.
[Edited on 14-6-2017 by JJay]
|
|
|
TheNerdyFarmer
Hazard to Others
Posts: 131
Registered: 30-9-2016
Member Is Offline
Mood: No Mood
|
|
Question
I know this is probably a simple question but how exactly does one discern the peroxide ion from the dioxide ion? Is it something to do with oxygens
electronegativity?
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Dioxide and peroxide aren't ions... dioxide means it contains two oxygens.
Peroxide means it contains at least two oxygens with a single bond to each other.
|
|
|
ninhydric1
Hazard to Others
Posts: 345
Registered: 21-4-2017
Location: Western US
Member Is Offline
Mood: Bleached
|
|
Campa Chem MSDS?
I plan to buy some Campa-Chem original holding tank fluid, but it seems that I can't access the MSDS to determine the concentration of formaldehyde
and methanol. Does anyone have access to such records and/or does anyone have the concentrations of the two chemicals above?
|
|
|
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 JJay | Dioxide and peroxide aren't ions... dioxide means it contains two oxygens.
Peroxide means it contains at least two oxygens with a single bond to each other. |
The peroxide ion is O2 with a charge of -2, as is found in barium peroxide and potassium peroxide.
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.
|
|
|
sparkgap
International Hazard
Posts: 1234
Registered: 16-1-2005
Location: not where you think
Member Is Offline
Mood: chaotropic
|
|
| Quote: Originally posted by ninhydric1 | | I plan to buy some Campa-Chem original holding tank fluid, but it seems that I can't access the MSDS to determine the concentration of formaldehyde
and methanol. Does anyone have access to such records and/or does anyone have the concentrations of the two chemicals above? |
I found the MSDS in the Wayback Machine (which I've attached), but there doesn't seem to be any info on the concentration.
sparky (~_~)
Attachment: Campa Chem.pdf (47kB)
This file has been downloaded 1891 times
"What's UTFSE? I keep hearing about it, but I can't be arsed to search for the answer..."
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Ok - to be fair, "dioxide" is not an ion.
"Peroxide" can be an ion if both of the oxygens are ionically bonded. But it is not a very stable one, and while ionic peroxides certainly should not
be ignored, covalently bonded peroxides are more common. Technically, an "oxide" ion also exists, as does a "superoxide" ion, although like peroxide,
these ions usually don't last very long as independent species.
[Edited on 19-6-2017 by JJay]
|
|
|
Darkstar
Hazard to Others
Posts: 279
Registered: 23-11-2014
Member Is Offline
Mood: Sleepy
|
|
@JJay:
Dioxide and peroxide are both ions, and are formed through single-electron transfer to molecular oxygen. The dioxide ion (also called "superoxide") is
O2− and is the result of one electron transfer, while the peroxide ion is O22− and the result of two
electron transfers:
O=O + e− → [•O−O:]− (dioxide)
[•O−O:]− + e− → [:O−O:]2− (peroxide)
So to answer TheNerdyFarmer, the difference is that the dioxide ion is two oxygen atoms connected through a single bond where one has an unpaired
electron and the other a full octet, while the peroxide ion is two oxygen atoms connected through a single bond but with both oxygen atoms having full
octets. Potassium dioxide (KO2) is an example of the former, and potassium peroxide K2 O2 ) is an example of the
latter.
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
Superoxide and dioxide are not the same thing. Carbon dioxide is not carbon superoxide, for example.
If you disagree, feel free to cite a reputable reference that describes the dioxide ion.
[Edited on 19-6-2017 by JJay]
|
|
|
Darkstar
Hazard to Others
Posts: 279
Registered: 23-11-2014
Member Is Offline
Mood: Sleepy
|
|
"Dioxide" is the correct IUPAC nomenclature for the superoxide anion. For example, if you check the Wikipedia page for potassium superoxide, you will
notice that it lists "potassium dioxide" as the IUPAC name. This is also mentioned on the Wikipedia page for the superoxide ion as well.
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
| Quote: Originally posted by Darkstar | | "Dioxide" is the correct IUPAC nomenclature for the superoxide anion. For example, if you check the Wikipedia page for potassium superoxide, you will
notice that it lists "potassium dioxide" as the IUPAC name. This is also mentioned on the Wikipedia page for the superoxide ion as well.
|
The IUPAC name for the superoxide ion is dioxide (1-), and the IUPAC states that superoxide is an acceptable alternative name. The IUPAC name for the
peroxide ion is dioxide (2-). While it is permissible to omit the charge notation where there is no ambiguity under IUPAC nomenclature, that is not
the case with dioxygen. Again, "dioxide" is not an ion.
Source: https://www.iupac.org/fileadmin/user_upload/databases/Red_Bo...
[Edited on 19-6-2017 by JJay]
|
|
|
Darkstar
Hazard to Others
Posts: 279
Registered: 23-11-2014
Member Is Offline
Mood: Sleepy
|
|
Right, but I am assuming that the context of his question was the difference between the anions in salts like "potassium dioxide" and "potassium
peroxide." We can argue nomenclature technicalities all day, but unless the anion is specifically designated as dioxide(2-) or the cation is prefixed
with di- (like "dipotassium dioxide"), it's probably a safe bet to assume that it is the superoxide anion in simple salts like those.
|
|
|
JJay
International Hazard
Posts: 3440
Registered: 15-10-2015
Member Is Offline
|
|
See page 80 for a discussion of this issue. "Potassium dioxide" is a simple stoichiometric name, *NOT* a compositional name.
[Edited on 19-6-2017 by JJay]
|
|
|
Darkstar
Hazard to Others
Posts: 279
Registered: 23-11-2014
Member Is Offline
Mood: Sleepy
|
|
Nice edit, but I am not "confused." I'm agreeing with you that "dioxide" by itself can be somewhat ambiguous. But the poster asked for the difference
between "dioxide" and "peroxide" as if they were two different anions. Can they mean the same thing or be confused for one another? Yes. But in my
experience you usually see "peroxide" for dioxide(2-), and either "superoxide" or "dioxide" for dioxide(1-). That's all I'm saying. It may not be 100%
correct, but that's what I see.
I agree that using "dioxide" by itself can create ambiguity depending on the cation, I'm not denying that.
Edit: And just so it's clear, my original response was to your reply to Draconic before you edited it to include superoxide ions.
[Edited on 6-19-2017 by Darkstar]
|
|
|
gluon47
Hazard to Self
Posts: 81
Registered: 20-9-2015
Location: oceania
Member Is Offline
Mood: fluorinated and dying
|
|
My school has given me the opportunity to do a few experiments in there lab. I noticed they had a bottle of anhydrous propionic acid, so I thought I
might make a propionate ester.
I would like to try isopropyl propionate. Fischer esterification should work for making this ester right?
Would adding anhydrous magnesium sulphate to the reaction mixture during reflux help to increase yield?
Any advice would be much appreciated.
reality is an illusion 
|
|
|
ninhydric1
Hazard to Others
Posts: 345
Registered: 21-4-2017
Location: Western US
Member Is Offline
Mood: Bleached
|
|
So does anyone know the concentration of formaldehyde and methanol in Campa-Chem, or is there a method (such as titration) to figure out the
concentration?
|
|
|
| Pages:
1
..
73
74
75
76
77
..
104 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
