| Pages:
1
2 |
nh4clo4
Harmless
Posts: 7
Registered: 27-11-2004
Member Is Offline
Mood: No Mood
|
|
Electrolysis with molten sugar
If you were to perform electrolysis through molten sugar would it split it in to graphite and water?
Pleas respond 
|
|
|
solo
International Hazard
Posts: 3975
Registered: 9-12-2002
Location: Estados Unidos de La Republica Mexicana
Member Is Offline
Mood: ....getting old and drowning in a sea of knowledge
|
|
Ref: Electrolysis with molten sugar
This might help you understand......solo
http://www.schoolresult.com/chemistry/electrolysis.htm
It's better to die on your feet, than live on your knees....Emiliano Zapata.
|
|
|
darkflame89
Hazard to Others
Posts: 255
Registered: 1-3-2004
Location: With probability 1, "somewhere" in this
Member Is Offline
Mood: No Mood
|
|
Obviously you do not understand electrolysis at all. Please take the pains to read up on it, not have other people to spoonfeed you.
Electrolysis does not work like that. It requires the presence of ions. Molten sugar does not contain ions, it is a covalent compound. Therfore,
electrolysing molten sugar will result in nothing.
Decomposing sugar to carbon and water do not require electrolysis. All u need is to add conc. sulphuric acid to sugar.
Have a nice day studying your chemistry textbook.
Ignis ubique latet, naturam amplectitur omnem.
|
|
|
KemiRockarFett
Hazard to Self
Posts: 84
Registered: 23-7-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by darkflame89
Obviously you do not understand electrolysis at all. Please take the pains to read up on it, not have other people to spoonfeed you.
Electrolysis does not work like that. It requires the presence of ions. Molten sugar does not contain ions, it is a covalent compound. Therfore,
electrolysing molten sugar will result in nothing.
Decomposing sugar to carbon and water do not require electrolysis. All u need is to add conc. sulphuric acid to sugar.
Have a nice day studying your chemistry textbook. |
Very arrogant answer and its wrong.
Sure you need ions but in fact its possible to make electrolysis if you apply enough electric field, high voltage, and the substance have got an
dipolmoment. Do you think pure water conduct due to its high H+ and OH- concentration at 10^-7 mol/dm3 ? Or because of it beeing an dipole that breaks
up in H+ and OH- than an high voltage is applied.
In fact if you want to split upp water you add som ions for example sulfuric acid to carry the current more effective but what is formed? persulphates
and hydrogen and oxygen so the summary will be electrolysed water and the same is very possible and has been done on different sugars for more than
hundred years ago.
For example an aqueous glucos solution go over to mannit via electrolysis at the cathode.
Its very well known that chemists know a days is so bad in electrochemistry that is a fact.
|
|
|
vulture
Forum Gatekeeper
Posts: 3330
Registered: 25-5-2002
Location: France
Member Is Offline
Mood: No Mood
|
|
You can't electrolyse molten sugar for the simple fact that it decomposes when molten...
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
|
|
|
Theoretic
National Hazard
Posts: 776
Registered: 17-6-2003
Location: London, the Land of Sun, Summer and Snow
Member Is Offline
Mood: eating the souls of dust mites
|
|
"Very arrogant answer and its wrong."
Bullshit. What's wrong? That you need ions for electrolysis? That nh4clo4 doesn't understand electrolysis and is showing it by suggesting
you can electrolyse molten sugar to water and graphite? That he should educate himself on the subject and spend some time reading his textbook?
And his post was in the wrong section as well...
"Sure you need ions but in fact its possible to make electrolysis if you apply enough electric field, high voltage, and the substance have got an
dipolmoment. Do you think pure water conduct due to its high H+ and OH- concentration at 10^-7 mol/dm3 ? Or because of it beeing an dipole that breaks
up in H+ and OH- than an high voltage is applied."
 What are you TALKING about? Pure water is an insulant, it's the
impurities that let it conduct. You think that liquid formaldehyde can be electrolysed? Sure, it has a dipole moment, but does it really matter? If it
doesn't ionise then it won't conduct. Does methylene chloride conduct?
"In fact if you want to split upp water you add som ions for example sulfuric acid to carry the current more effective but what is formed?
persulphates and hydrogen and oxygen so the summary will be electrolysed water and the same is very possible and has been done on different sugars for
more than hundred years ago."
Specify an example, please.
"For example an aqueous glucos solution go over to mannit via electrolysis at the cathode."
Reduction by nascent hydrogen maybe?
"Its very well known that chemists know a days is so bad in electrochemistry that is a fact."
Very well known? A fact? Where's your data coming from? You sure don't know too much about electrolysis yourself, since you think that
methylene chloride can be electrolysed (and everything else with a dipole moment) and think that "electric field, high voltage" are two
different things when in fact electric field is created by a voltage difference.
"Have a nice day studying your chemistry textbook."
[Edited on 22-1-2005 by Theoretic]
|
|
|
KemiRockarFett
Hazard to Self
Posts: 84
Registered: 23-7-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by vulture
You can't electrolyse molten sugar for the simple fact that it decomposes when molten... |
Thats very very true 
But I am sure that you are understanding the thing that I tried to explain. A compound does not nead to be ionic at all to obey electrolysis. ( BUT it
must be possible to form ions carrying the electrons, or you add something wich is ionic and run the electrolys on it)
The best thing with electrolysis is that one can do so much chemistry with it. BUT very many chemist does not now a shit about it. For example in
Sweden there I live at the universitys they have no research at all on electro chemitry, yes okey at corrossion maybe. And than talking to some old
professors they find everything about electrolysis out of water as strange. Some of them have applied it in organic synthesis but thats not so common
either due to the fact that organic chemists often hate things like electricty and calculations and mathematics, and the inorganic chemists often
sucks totaly on chemistry because they are more interested to estimate celledges with x ray diffraction and neutron data. A real chemist should be
specialised in all the fields !!
[Edited on 22-1-2005 by KemiRockarFett]
|
|
|
KemiRockarFett
Hazard to Self
Posts: 84
Registered: 23-7-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by Theoretic
"Very arrogant answer and its wrong."
Bullshit. What's wrong? That you need ions for electrolysis? That nh4clo4 doesn't understand electrolysis and is showing it by suggesting
you can electrolyse molten sugar to water and graphite? |
Yes you need ions and you will form them than you applie pluss and minus on a system that is polarisable. Do you think all things obeying electrolysis
is ionic for example Al2O3? haha no way the ionic character in Al2O3 is little !!!! Its an covalent compound which electrolyse quite well.
In this forum you have got an big text file several hundered sides in a book inscannad to download I think its under this session. I think you should
read it. Its old but it shows a lot of fashinating electrolysis:
http://www.archive.org/details/ElectroChemistryForOrganicCom...
[Edited on 23-1-2005 by chemoleo]
|
|
|
cyclonite4
Hazard to Others
Posts: 480
Registered: 16-11-2004
Location: is unknown
Member Is Offline
Mood: Amphoteric
|
|
Do you have a spelling problem, or are you just too lazy to make yourself clear?
\"It is dangerous to be right, when your government is wrong.\" - Voltaire
|
|
|
BromicAcid
International Hazard
Posts: 3245
Registered: 13-7-2003
Location: Wisconsin
Member Is Offline
Mood: Rock n' Roll
|
|
Please, let's keep things civil.
By definition:
The properties of ionically bonded substances:
Hard
Conduct heat and electricity (when molten or in solution)
High melting points
The properties of covalently bonded substances are:
Low melting point
Insulators of heat and electricity
Al2O3 is indeed ionic, the differences between ionic character and covalent character could easily be shown by comparing MnO2 to Mn2O7, the latter
showing considerable covalent character. Electrolysing molten Al2O3 does indeed give aluminum metal. Yes, you can electrolyse molten sugar just as
you can air, run enough current and volts through any insulator and you can jump between electrodes as long as the distance isn't too far,
doesn't mean you'll get anything productive or even that you're doing electrolysis. Look through that book you just linked us to, the
reactions with organic chemistry and electrolysis usually take advantage or some reactive molecule formed at an anode or cathode doing its buisness
with the organic molecules around, not the organic molecules doing the direct reaction. For example this article on Industrial Electrochemical Organic Synthesis has one distinctive paragraph that goes over the intermediate compounds
formed: | Quote: | | There are many other differences seen in organic electrosynthesis compared to conventional organic synthesis. Useful concentrations of highly
reactive cation or anion radicals, not easily or so far impossible to make chemically, can be easily and conveniently produced electrochemically.
The resulting electrosynthesis products can be unique (that is not before synthesized by chemical means, or so difficultly made by chemical means that
many steps would be required). Many other reactive species can be made conveniently, including superoxide ion, hydroxyl radicals, peroxide, CO2 anion
radicals, hydrogen atoms and metal hydrides, and halogens, including fluorine. On the cathode side of the cell, at high negative potentials,
solutions of solvated electrons can be readily made and on the anode side, at high positive potentials, powerful oxidants like fluorine, persulfate
salts, and ozone. Acid can be made at the anode and alkali at the cathode. |
Most of the organic
electrosynthesis reactions involve inorganic ionic compounds added that serve as the intermediates, yes, some electrochemical reactions can happen
directly on the organic molecules, but there are other factors involved too.
|
|
|
Cyrus
Hazard to Others
Posts: 397
Registered: 24-4-2004
Location: Ancient Persia
Member Is Offline
Mood: No Mood
|
|
While we're on the topic of sugar...
When heated what does it decompose into? Amorphous carbon or graphite? Also, if it's amorphous carbon, when does that change into graphite?
(assuming standard pressure) Sorry if this is spoonfeeding, but I've done the mandatory google search many times.
Here's another thing I've heard on the internet-
~
When graphite is intercalated with sulfuric acid, graphite sulfate is formed. On rapid heating this is transformed into a voluminous worm-like mass
similar to the expanded vermiculite used in potting mixtures. This mass is compacted by rollers into foil which is used to make gaskets, which
substitute for asbestos. The graphite foil resists high temperatures and chemicals. US consumption is about half of that of the world. Russian
researchers have identified that expanded graphite is an excellent adsorbent for oil spills.
~
http://industrialmineralsinc.com/about.html
~
Graphite sulfate? Kind of interesting.
|
|
|
darkflame89
Hazard to Others
Posts: 255
Registered: 1-3-2004
Location: With probability 1, "somewhere" in this
Member Is Offline
Mood: No Mood
|
|
I am sorry over my controversial answer. Pure water can be electrolysed if you apply a high enough voltage. And excellent example is:http://www.powerlabs.org/waterarc.htm
But we are talking about conventional current and voltage here, and electrolysis generally applies to ions, though certain organic molecules can be
oxidised or reduced, but this is more complex. I only meant nh4clo3 to start from the basics first.
Ignis ubique latet, naturam amplectitur omnem.
|
|
|
KemiRockarFett
Hazard to Self
Posts: 84
Registered: 23-7-2004
Member Is Offline
Mood: No Mood
|
|
| Quote: | Originally posted by BromicAcid
Please, let's keep things civil.
By definition:
The properties of ionically bonded substances:
Hard
Conduct heat and electricity (when molten or in solution)
High melting points
The properties of covalently bonded substances are:
Low melting point
Insulators of heat and electricity
|
Yes that is a good explaniation of my posts. You run the electrolysis over some other substance added to the substance, for example sulphates which
will produce persulphates of different kind at the anode and this substance do an oxididation of the other compound in the mix and go back to sulphate
and over and over again.
What I meant by all my posts was only that you point out, and that is if you have extremly high voltages you can bump electricity in most things.
But that is not the case in ordinary electrolysis so the anwer to guestions like: Can I electrolyse acetone, sugar solutions and such things? No
should be the answer, but you can add ions of some other materials to do interesting chemistry with electrolysis etc.
( Due to my spelling, every mod good in english feel free to correct my spelling I spell as good as I can )
Edit by C.: Please dont quote FULL messages! As to spelling...aren't there fantastic inventions such as spell-checking programs?
[Edited on 23-1-2005 by chemoleo]
|
|
|
chemoleo
Biochemicus Energeticus
Posts: 3005
Registered: 23-7-2003
Location: England Germany
Member Is Offline
Mood: crystalline
|
|
I think the logic of the original poster is
NaCl --> electrolysis --> Sodium at the cathode, chlorine at the anode
Sugar ('Carbon-hydroxides' --> electrolysis --> Carbon at the
cathode (plus hydrogen), oxygen at the anode.
Shame only sugar isn't ionic.
Kemi, what you are on about is something else than the answer to the original question, and the original answer by darkflame is certainly NOT wrong.
Cyrus, are you aware of any instance where a chemical decomposition of an organic molecule yields graphite?
I always thought graphite is produced when ordinary carbon is pressurised.
Never Stop to Begin, and Never Begin to Stop...
Tolerance is good. But not with the intolerant! (Wilhelm Busch)
|
|
|
sparkgap
International Hazard
Posts: 1234
Registered: 16-1-2005
Location: not where you think
Member Is Offline
Mood: chaotropic
|
|
Now that Cyrus mentions graphite intercalation compounds, I read about graphite nitrate in the nitration book I mentioned in the nitroalkane thread.
Something there said that it is used for nitration much like nitric/sulfuric acid.
I will post more about it once their words get through my thick skull.
Oh, and the carbon produced by pouring vitriol on sucrose is amorphous. Not enough time to order itself into the neat hexagonal array that is
graphite.
Since that was off-topic, I should mention that a good number of compounds decompose when subjected to a sudden influx of current (but that is more
often due to the heat produced), but I do not at all believe that this was what nh4clo4 had in mind.
sparky
P.S.
Quoting KemiRockarFett:
"(sic) ...A real chemist should be specialised in all the fields..."
That was oxymoronic. How can you specialize if you're into everything?
|
|
|
Cyrus
Hazard to Others
Posts: 397
Registered: 24-4-2004
Location: Ancient Persia
Member Is Offline
Mood: No Mood
|
|
Chemoleo, as a matter of fact, I am aware of an organic decomposition that produces graphite.
Wood. Seriously. I was just doing some ceramics tests (again!) and was heating a crucible on top of a block of wood. The bottom of the crucible had
nice areas of quite shiny, adhesive, and electrically conductive graphite on the bottom after being heated. It didn't get above an orange heat
IMO either, so this is something anyone can try- heat a plate (not paper) on top of a piece of wood (not the table).
Yesterday I was doing some other tests in my furnace using wood and coal, and some of the pieces then had even nicer shiny graphite spots.
I'd like to try "graphitizing" things by heating them in a closed chamber with wood.
Also, do a search on "pyrolytic graphite" IIRC methane is used.
Sorry, this is OT- new thread maybe?
[Edited on 24-1-2005 by Cyrus]
|
|
|
mick
Hazard to Others
Posts: 338
Registered: 3-10-2003
Member Is Offline
Mood: No Mood
|
|
And than talking to some old professors they find everything about electrolysis out of water as strange. Some of them have applied it in organic
synthesis but thats not so common either due to the fact that organic chemists often hate things like electricty and calculations and mathematics, and
the inorganic chemists often sucks totaly
As an organic chemist by trade a quick comment.
If the old professor or the organic chemist did not like electric how do LCD screens work. If they electrolysed I do not think they would last very
long.
I think MRI came from NMR + computers. I work in a place where having a super cooled , super conducting magnet is routine. Fill it up with liquid N2
every week and the liquid He (at near absolute zero) needs topping up every 3 months. Electric zero, keeping it cold costs.
mick
|
|
|
Mumbles
Hazard to Others
Posts: 436
Registered: 12-3-2003
Location: US
Member Is Offline
Mood: Procrastinating
|
|
I doubt most of you have it, but in a pyrotechnic book I have, they actually have a way to make graphite at standard pressure. It is part of the
charcoal making proceedure, with things to avoid. You can convert an amount of wood to pure graphite at 1000C for 24 hours. I think it is 2 pounds
of charcoal going to 95+% graphitic structure. I had have some lampblack laying about, it is highly unconductive. I heated about 15g with a natural
gas flame for about 5 hours. I was suprised when I got a decently conductive material. I think heating any carbon structure will go to graphite.
Charcoal would go faster than a totally amorphous form in my opinion. The heat closes the broken graphitic ring structures, which is one of the main
reasons that charcoal is much better in pyrotechnics than graphite, and more reactive.
The book is Black Powder Manufacturing, Testing & Optimizing
By Ian von Maltitz
|
|
|
JohnWW
International Hazard
Posts: 2849
Registered: 27-7-2004
Location: New Zealand
Member Is Offline
Mood: No Mood
|
|
You had better scan to PDF or DJVU your book "Black Powder Manufacturing, Testing & Optimizing", and upload it to the FTP, then.
|
|
|
Mumbles
Hazard to Others
Posts: 436
Registered: 12-3-2003
Location: US
Member Is Offline
Mood: Procrastinating
|
|
It's already scanned and OCR'ed in pdf. I think it is that book. It is at my other house, but I looked on Skylighter and it is the one
that mentioned charcoal testing. The only problem is that it was scanned by another person. I'll see if I can get permission from him for an
upload. He is really nice about stuff like this, so he'll probably go for it. If not I could make an excerpt of the graphite part.
|
|
|
Marvin
National Hazard
Posts: 995
Registered: 13-10-2002
Member Is Offline
Mood: No Mood
|
|
I think it is a mistake to assume that most of the carbon atoms in lampblack are not in the form of intact hexagonal lattice sections. Lampblack is
suitible for oxidation to mellitic acid for example. The graphite layers only conduct in 2 dimensions so fairly long range order is needed for a
decent effect in a bulk powder/solid.
I'm happy with the convensional pore/volatiles explanation of the performance, or lack of it, of graphite in black powder mixtures unless you
have more info.
|
|
|
Cyrus
Hazard to Others
Posts: 397
Registered: 24-4-2004
Location: Ancient Persia
Member Is Offline
Mood: No Mood
|
|
While we're on the offtopic of carbon, what is the easiest way to get colloidal graphite?
The smallest size carbon I know how to get is lampblack, which I could then heat treat in my furnace to get some graphite.
The reason I ask is that I need to electroplate something large, (yes still haven't done that) and it's a plastic. So I need a conductive
coat first- apparently aquadag can be used, which is water, and graphite peptized by tannin. This vould be sprayed on the plastic part, and then
immersed in a electroplating bath. (with CuSO4, H2SO4, etc)
VVould the tannin mind? I'm vorried that the graphite solution will just "dissolve" off in the plating bath.
|
|
|
khlor
Hazard to Self
Posts: 95
Registered: 4-1-2014
Location: Who knows, really...
Member Is Offline
Mood: No Mood
|
|
in fact, with the proper compounds in place it can be done:
http://nvlpubs.nist.gov/nistpubs/jres/6/jresv6n6p1145_A2b.pd...
but there will be no graphite and/or water
"NOOOOOO!!! The mixture is all WROOOOOOONG!"
|
|
|
aga
Forum Drunkard
Posts: 7030
Registered: 25-3-2014
Member Is Offline
|
|
10 year old thread, and i still can't see why they didn't just try it and see.
Not as if it'd be a difficult or expensive process.
|
|
|
DraconicAcid
International Hazard
Posts: 4332
Registered: 1-2-2013
Location: The tiniest college campus ever....
Member Is Offline
Mood: Semi-victorious.
|
|
| Quote: | Yes you need ions and you will form them than you applie pluss and minus on a system that is polarisable. Do you think all things obeying electrolysis
is ionic for example Al2O3? haha no way the ionic character in Al2O3 is little !!!! Its an covalent compound which electrolyse quite well.
|
Who does electrolysis of alumina without dissolving it in molten cryolite (sodium hexafluoroaluminate, in which it will ionize) first?
[Edited on 28-5-2015 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.
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
