Talk:Electrolysis

message: The use of stainless steel(SS) as an anode should be approached with great caution or best yet, avoided altogether. SS contains chromium. No matter what misinformation you may have read on the internet, SS anodes ARE INDEED consumed. During consumption highly toxic chromates are released into the electrolyte. Hexavalent chromium is extremely toxic and highly carcinogenic. Disposal of this electrolyte into the ground or down the drain is illegal and poses risks of contaminating ground water and city water supplies. Touching this chromate-containing electrolyte must also be avoided by all means.
The main page of this article should be updated to reflect the extreme toxicity the use of SS anodes will introduce into the used electrolyte solution.  —Preceding unsigned comment added by 67.186.20.215 (talk) 17:48, 12 October 2008 (UTC)
thread_title: Stainless Steels and Anode Consumption

message: In my opinion, his name should be removed from the experimenters' list, as even if he has made a significant contribution to hydrogen powered cars, which I personally doubt, this is not really electrolysis research.2corner (talk) 10:48, 24 July 2008 (UTC)
thread_title: Stanley Meyer

message: What are some typical efficiencies then? - Omegatron 03:43, Jun 26, 2005 (UTC)
Numbers are all over the place:
*"real-world efficiencies range from 83% under laboratory conditions to as low as 66% in a typical commercial-scale facility." 
*"Such a high-temperature system has the potential to achieve overall hydrogen production efficiencies in the 45 to 50 percent range, compared to approximately 30 percent for conventional electrolysis." 
*"With output pressures of 0.2 - 0.5 MPa these processes can reach efficiencies, related to the lower heating value of hydrogen, of around 65%."  "Operating efficiencies lie in the 50-60% range for the smaller electrolysers and around 65-70% for the larger plants." 
*"Hydrogen production by electrolysis is about 80% efficient considering only the electricity, but the thermal efficiency of producing that electricity ranges from about 34% in light water reactors to 50% in advanced systems, giving overall efficiencies of 25-40%. A significant investment in electrolytic cells is also required. The oxygen by-product also has value." 
*"Some of NHE’s electrolysers have an efficiency of over 80% (high heating value)." "Efficiency factors for PEM electrolysers up to 94% are predicted, but this is only theoretical at this time." "Another type of steam electrolyser is the German “Hot Elly”; this system can reach an efficiency of 92%."
*"Norsk Hydro Electrolyzers (NHE) is currently one of the world's leading producers of electrolyzers, and they have an efficiency of about 85%." 
*"The best available technology captures 90% of the energy on a HHV basis and 76% on a LHV basis." 
There appears to be a discrepancy between the pure efficiency of hydrogen and oxygen production vs input power, and the same with resistive heating of the water included?
*"Hydrogen production from natural gas commonly employs a process known as steam reforming. ... Most of the hydrogen utilized by the chemical and petroleum industries is generated with steam reforming. Steam reforming reaches efficiencies of 70% - 90%."  - Omegatron 23:57, July 30, 2005 (UTC)
"Just a thought... there is a link to a .pdf file on this page and it uses the Adobe Acrbobat icon. I personally hate the Adobe .pdf view and use a different open source type viewer, I would have to see Adobe become synonymous with pdf files. This is just a general thought for all of wikipedia." (my first post, sorry if it's not to code) Ummmcam 03:24, 28 September 2006 (UTC)
thread_title:  Efficiency 

message: The reader, at the beginning of the overview, is presented with the phrase "A source material" - a person who is a non scientist
sees an undefined idea here... which can throw off his comprehension. It would be nice to add a clause "A source material, such as a metal or..." Would someone with a hands on familiarity with electrolysis be kind enough to add a couple words there?
::Some electrolytes for water could include sodium chloride NaCl(table salt), sodium hydroxide NaOH (lye), Potassium hydroxide KOH(Potash lye), and Bicarbonate of soda NaHCO3 (baking soda).  These are easy to acquire and are simple to use.  Sodium chloride and bicarbonate of soda are safe for beginners to handle.I55ere (talk) 15:01, 5 March 2008 (UTC)
replies: text: ..."Sodium chloride and bicarbonate of soda are safe for beginners to handle.I55ere (talk) 15:01, 5 March 2008 (UTC)
replies: text: I think table salt is not safe for beginners- I read somewhere that it will release poisonous Chlorine gas. Scary, this would be an easy/common error in novice kitchen chemistry! Is Chlorine really released?Electricmic (talk) 02:41, 14 May 2010 (UTC)
thread_title: What source materials are typically used to give us the ions?

message: Is electrolysis a type of DC circuit?
--Sean; 24 September 2005
Yes.  Most, if not all, electrolysis is done using a DC circuit. --Heron 14:07, 25 September 2005 (UTC)
thread_title:  DC Circuits 

message: It is known fact that electrolysis damages terminals of DC power supply in humid environments. I think this should be mentioned in the article. Car batteries usually have special insulation device on the positive terminal. Communication equipment uses -48V standard power supply to tackle this issue. --Michagal 16:06, 9 August 2006 (UTC)
thread_title:  Damages of electrolysis 

message: What reaction will occur at anode in the electrolysis of potassium dichromate? What product will be formed???Superdvd 10:53, 26 January 2007 (UTC)
replies: text: Dichromate is reduced to chromium(III). Bbi5291 18:48, 23 September 2007 (UTC)
thread_title:  potassium dichromate 

message: I am not certain, but the deffinition, to me, would seem to be a bit inadiquite and lacks detail... anyone agree? 
:I think that it should include the fact that the compound/element must either be dissolved, melted or the anode/cathode in some cases. 
I agree...though with predescending thoughts.[ZHK]
any ideas on this? —The preceding unsigned comment was added by BenHowes (talk • contribs) 16:41, 6 February 2007 (UTC)
thread_title:  definition? 

message: Copper has a long history of being smelted and used from simple ores. Does anyone have an objection to replacing copper with aluminum? Until fairly recently (1850's) aluminum was more valuable than gold precisely because it requires an electrical current to separate from its ore.--Legomancer 02:00, 1 June 2007 (UTC)
thread_title:  Replace Copper in First Paragraph 

message: Although science-minded people like us think of the chemical kind of electrolysis first, there's also cosmetic electrolysis, i.e., the hair removal process.  Some articles (Rita Hayworth for one) link to this article in reference to the cosmetic procedure, which is pretty strange, as I'm pretty sure Rita's water and other molecules stayed mostly bonded throughout her life.  Recommend the creation of a separate article, something like "Electrolysis (cosmetic)", unless someone has a better idea. --Iritscen 19:28, 7 June 2007 (UTC)
replies: text:  There is already a link to Electrology at the top of the page, but maybe it is not clear from the wording that this is the cosmetic procedure. --PeR 09:43, 8 June 2007 (UTC)
replies: text: Ahh, I missed that somehow.  Thanks for clarifying, and for fixing the link from Rita's article. --Iritscen 17:20, 6 July 2007 (UTC)
thread_title: The Other Electrolysis

message: Entire portions of the electrolysis entry were plagiarized from the web site of CR Scientific LLC without providing so much as a link or reference.
I should know.  I am the original author of the following.  In fact, I spent a great deal of time on the wording:
"In electrolysis, the anode is the positive electrode, meaning it has a deficit of electrons; species in contact with the anode can be stripped of electrons (i.e., they are oxidized). The cathode is the negative electrode, meaning it has a surplus of electrons. Species in contact with the cathode tend to gain electrons (i.e., they are reduced)."
"A higher current flow (amperage) through the cell means it will be passing more electrons through it at any given time. This means a faster rate of reduction at the cathode and a faster rate of oxidation at the anode. This corresponds to a greater number of moles of product. The amount of current that passes depends on the conductance of the electrodes and electrolyte, though it also depends on how much current the power source itself can generate.
Current also makes a difference in that it can shift chemical equilibria by sheer mass action. The processes in an electrolytic cell with just two or three reactants can become very complex. Most of the time it is best to search the literature to see what current density works best for a desired process. For instance, metals plated at a certain current density might form a durable and shiny coating on the substrate, whereas some other current density might form an excessively grainy, dull coating.
A higher potential difference (voltage) applied to the cell means the cathode will have more energy to bring about reduction, and the anode will have more energy to bring about oxidation. Higher potential difference enables the electrolytic cell to oxidize and reduce energetically more "difficult" compounds. This can drastically change what products will form in a given experiment. On a practical level, both current and voltage determine what will form in a cell."
-------------
Although it is flattering that someone chose my company's article as a source for a Wikipedia entry, the manner in which it was handled was inappropriate and represents a  copyright violation.  
I suggest that the article be edited as soon as possible to remedy the infringement;  while CR Scientific LLC has no problem with quotations and paraphrasing, plagiarism of our articles is unacceptable.
In the meantime I am going to read over the rest of the article to see if any other phrases have been lifted directly.  We have CD archives of our articles going back several years in the event there is any confusion.
Sincerely,
Christian Thorsten
CR Scientific LLC  —Preceding unsigned comment added by Crsci9 (talk • contribs) 13:26, 25 February 2008 (UTC)
replies: text: I have removed the infringing text from the article. Someone should check the article to ensure that it continues to make sense with these paragraphs removed. - Mark 14:43, 25 February 2008 (UTC)
thread_title:  Copyright infringement / plagiarism;  please remedy 

message: I may be wrong, but I am pretty sure the definition and usage of the term Lower Calorific Value is wrong, and I have corrected it to what I think is correct. Engineman (talk) 09:17, 9 June 2008 (UTC)
thread_title: efficiency of electrolysis

message: Penn State and Oregon State University both have projects to do this.
The advantage of sewage over plain water is that with water you often need to add ions. Sewage already has ions in it, so it is already a good conductor of electricity. Sewage is also something that we already want to reduce in volume, and the removal of the H2 and the accompanying O2 from it accomplishes a size reduction, and produces at least one useful thing. Part of sewage treatment is the process of "dewatering", and the electrolytic producton of hydrogen from sewage does this. Furthermore, if you can condense the water that reoccurs when the Hydrogen has been "burned" you have clean water.
John5Russell3Finley (talk) 15:51, 25 January 2009 (UTC)
thread_title: electrolysis of sewage

message: In the section Competing half-reactions in solution electrolysis these values for the oxidation and reductions of water are quoted:
    the electrode potential for the reduction producing hydrogen is −0.41 V
    the electrode potential for the oxidation producing oxygen is +0.82 V
I think they are wrong. As they are, they seem to suggest that the electrolysis of water is a spontaneous change, when it clearly is not. The literature quotes the reduction of water to produce hydrogen gas as -0.83 V and the oxidation of water to produce oxygen gas as -1.23 V. Whoever added those values has mixed them up pretty badly.
Before I change them, I hope someone can verify that I am correct in this.
rrh02 (talk) 00:55, 06 February 2019 (UTC)
thread_title: Error in E values for electrolysis of water

message: The text that states the processes in the electrochemical cell are the "reverse" of electrolysis are just wrong. If cells were the "reverse process" then ionic solutions would spontaneously generate electricity - this does not happen. The cell has a specific setup and relies on differences in electrode potential. I have tried to clarify this.
Clive long (talk) 09:32, 29 January 2009 (UTC)
replies: text: reversible - surely they are if you take account of the gaseous components of H2 and Cl2 -  for example when  hydrogen chloride  solutions are electrolysed then the creation of bubbles of hydrogen and oxygen at the cathode and anode create an overpotential- try stopping a cell and then putting a voltmeter across there is a temporary reverse emf - effectively electrolysis has created a short lived "hydrogen" electrode and a "chlorine" electrode  which connected externally form a galvanic cell. The effect would persist if H2 and Cl2 were continuously bubbled over the electrodes.--Axiosaurus (talk) 15:22, 20 February 2009 (UTC)
thread_title: References to electrochemical cell

message: The following section has a few blatant mistakes but more important implies rationals that are false.  First off electrolysis a NaCl solution results in Chloralkali process unless electrocatalysts are used that can facilitate the two half reactions involved in splitting hydrogen. Platinum is one such electrocatalyst.  Furthmore if a Zn electrode is used the Zn doesn't dissolve it is oxidized from Zn to Zn2+ in because Zn2+ has a more negative reduction potentials than O2.  The reason "reactive metal electrodes" aren't used to produce "large quantities of hydrogen" is because the implied alloys are poor electrocatalysts, contamination issues are not a major concern with current technology.  I'm not sure where this content came from but it needs to be cited if it returns in any form.--OMCV (talk) 02:49, 29 June 2009 (UTC)
thread_title:  Problems with section. 

message: From the Electrochemistry section(in the electrolyte page):
"instead, a chemical reaction occurs at the cathode consuming electrons from the anode, and another reaction occurs at the anode producing electrons to be taken up by the cathode."
This apparently seems contradictory to what that is in Process of electrolysis on the electrolysis page, which says:
"Positively-charged ions (cations) move towards the electron-providing (negative) cathode, whereas negatively-charged ions (anions) move towards the positive anode."
The Electrochemistry section states that the cathode consumes electrons [?what does "from the anode" mean?] and the anode produces electrons. However, the electrolysis page states that the cathode provides the electrons, which would mean that the anode takes up the electrons.
Isn't there something wrong?
PS I also posted this on the electrolyte talk page since this concerns both pages.
218.186.9.231 (talk) 15:53, 4 March 2010 (UTC)
thread_title:  Electrolyte (Electrochemistry)/electrolysis 

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thread_title:  External links modified 

message: Quote: ...at the electrodes is directly proportional to their equivalent weight.
1. To who's equivalent weight? The electrodes?
2. Is "equivalent weight" a special term from physics or just saying that the mass of released material is proportional to the equivalent weight of the <thing answered in question 1> ?
פשוט pashute ♫ (talk) 14:05, 5 September 2017 (UTC)
thread_title:  unclear law 

message: Direct current is in no way a requirement. Electrolysis is a phenomenon whereby chemical reactions occur due to an electric current. It doesn't matter what form. However, for nearly all practical applications, DC is used. But in fields such as analytical electrochemistry, AC is used (e.g., cyclic voltammetry). This article needs to clearly differentiate between the phenomenon and its exploitation.
71.50.180.112 (talk) 15:49, 26 December 2017 (UTC)
thread_title:  DC is not a requirement 

message: I'm going to add some more to the history about some other scientists who helped develop the idea, such as Luigi Galvani and Sir Humphrey Davy. Makaylacg (talk) 01:59, 1 November 2019 (UTC)
thread_title:  History of electrolysis