Talk:Standard electrode potential (data page)

Li vs K

Can someone please explain to me why Li has a lower value than K (for example), but K is more electropositive? Thanks... -postglock 13:01, 30 December 2005 (UTC)

It has to do with the solvation of the Li+ ion. Because Li+ binds water molecules so strongly, it is very favourable to create solvated lithium ions in aqueous solution and the electrode potential is very negative. Electronegativity does not consider solvation, as it concerns either molecules or ions in the gas phase (Pauling and Mulliken electronegativities respectively). Physchim62 (talk) 20:34, 2 February 2006 (UTC)

Thanks Physchim62, excellent response... -postglock 22:40, 2 February 2006 (UTC)

The standard reduction potential for Ce⁴⁺(aq) + e^- → Ce³⁺(aq) is missing from the table. I've tried searching for a value for this, but all I end up with are contradictions. Does anyone have an E^o for this from a reliable source? 199.90.6.26 03:25, 1 February 2007 (UTC)

The values below are standard electrode potentials taken at 298 K, 1 bar pressure and in aqueous solution, of concentration 1 molar

This is not accurate, all activities should be 1 M, not concentrations —Preceding unsigned comment added by 155.69.52.189 (talk) 11:07, 11 March 2008 (UTC)

for Ce4+(aq) + e- → Ce3+(aq), try http://www.jesuitnola.org/upload/clark/Refs/red_pot.htm —Preceding unsigned comment added by Asd456 (talk • contribs) 13:12, 11 March 2008 (UTC)

Electrode potential vs. electronegativity?

How could it be explained that metals with not too high electronegativity such as Cobalt have high electrode potential (+1.82 V) while more electronegative elements such as sulfur (+0.14 V) and iodine (+0.53 V) have lower electrode potential? —Preceding unsigned comment added by 24.203.220.62 (talk) 18:44, 3 March 2011 (UTC)

Sortable table

The sortable table (which is new as of today) is great. The only difficulty is that it missorts the "≡ 0" line when you sort by potential. Karl Hahn (T) (C) 00:34, 3 May 2008 (UTC)

There is apparently a bug in sorting with negative numbers. Let us hope it will get fixed one day. Cheers. Stan J. Klimas (talk) 14:39, 3 May 2008 (UTC)

It appears to be doing an alpha sort instead of a numeric sort. That's why it comes out like it does, '+' is before '-' in ASCII order. Hgrosser (talk) 07:14, 7 May 2008 (UTC)

It now sorts correctly by potential, but only from negative to positive (click 3 times) and not in Safari. Hgrosser (talk) 06:01, 12 May 2008 (UTC)

Thank you! Seems to work really well. Stan J. Klimas (talk) 12:29, 17 May 2008 (UTC)

→ or ⇌

I think the equations should use ⇌ instead of → . After all, the data are for chemical equilibrium. Would anybody have a better typographic suggestion or other preferences? Cheers. Stan J. Klimas (talk) 19:23, 23 May 2008 (UTC)

For my taste, $\rightleftarrows$ and −3.05 (as suggested by Hgrosser) look better than ↔ and -3.05. Stan J. Klimas (talk) 23:48, 4 June 2008 (UTC)

Except it's not. Not necessarily, anyway. The voltages only hold if the reaction is traveling in the forward direction. The voltage given for Li+ +  e− ⇌ Li(s) only holds if the reaction is occurring in that order; from Li+ to Li. Unless I'm completely off my rocker, which is fairly possible. --70.18.11.87 (talk) 05:54, 10 April 2011 (UTC)

Standard state for amalgam solutions

For the standard state of metals in the metal-mercury amalgam, I found the following reference "Standard potentials of amalgam electrodes in aqueous solutions, temperature coefficients, and activity coefficients of metals in mercury", Pure and Applied Chemistry 57 (1) , 169 - 179 (1985), http://www.iupac.org/publications/pac/1985/pdf/5701x0169.pdf

It appears to define the standard state in the mercury amalgam on the mole fraction scale, at infinite dilution. Cheers. Stan J. Klimas (talk) 23:00, 9 September 2008 (UTC)

Make this article comprehensible to non-experts?

This article is useful for non-scientists trying to understand batteries and galvanic cells in general. However, the formal molecular structure listing only makes this table mostly incomprehensible to the average person.

Would anyone object to a new column being added, which includes the common English word definitions for each type of material?

It is too much to expect a casual reader to click on a hundred article subpage links to find out what common chemical each of these formulas actually represent.

DMahalko (talk) 07:37, 23 March 2009 (UTC)

If you can't understand chemical formulae, you certainly can't understand the data in this table. If non-scientists want to understand batteries and galvanic cells, they should really go to those articles, not try to pretend to understand something which they evidently don't. Physchim62 (talk) 08:07, 23 March 2009 (UTC)

(ec) You don't need to click on the links – mouseover reveals the common English word. Where it is linked, anyway :) Also, with up to four "chemicals", several of them fairly complex, I fear such a column may end up cluttered and equally incomprehensible. Might still be worth a try, but I rather doubt it. — the Sidhekin (talk) 08:13, 23 March 2009 (UTC)

Okay, so skip spelling out the full name for the really exotic and complex formulas.

At least the common and simple elements should be noted and called out from the really complex stuff, for people looking to quickly see the potentials for say Zinc and Carbon, Nickel-metal hydride, Nickel-Cadmium, Lithium-ion, and other common battery materials.

Physchim62, it's not helping to improve the knowledge base of young Wikipedia readers to have a snooty academia nose-in-the-air attitude about the data in this table. A short list of common elemental electrode potentials with the chemical names spelled out appears in practically every high school physics book. This table could provide that too. DMahalko (talk) 13:47, 23 March 2009 (UTC)

No, Wikipedia should be accomodating of the novice as well as the expert: that's not the same as saying that every single article should aim to to that. It is pernicious to molly-coddle "novice" users, as it prevents them from being able to seek out information on their own from other sources. That is why our higher level science articles use the standard nomenclature and terminology from the rest of the scientific literature, not because of any sort of "academic snobbery". Wikipedia is not a textbook.

If your hypothetical novice who came upon this page were to try to use it to calculate the potential of a real galvanic cell, they would get the wrong answer: why they would get the wrong answer is an interesting and important piece of science it itself (there are two main reasons). In the meantime, I have no objection to you placing standard electrode potentials in, say, Zinc-carbon battery, Nickel-metal hydride battery, Nickel-cadmium battery, Lithium-ion battery or anywhere else that takes your fancy: you might like to change the titles while you're at it, as none of them conform to WP:NAME… Physchim62 (talk) 15:24, 23 March 2009 (UTC)

Rather than merely flaunting your knowledge that this data would give wrong answers for galvanic cell calculations, it would be much more beneficial for all concerned if you would share this knowledge and include it as an introduction to this table so that the unwashed masses visiting this page can learn these details. But I suppose it is more fun to sit smugly in your ivory tower thinking to yourself, "these idiots..." DMahalko (talk) 18:50, 26 March 2009 (UTC)

The information would be much better on the articles which discuss the concepts concerned: that way, even people as lazy as yourself might be able to find it. Physchim62 (talk) 19:00, 26 March 2009 (UTC)

A person coming directly to this article would not find that information. If it is already described better elsewhere, a descriptive link to that page would be all you'd need to add. Since you like quoting policies, this is called WP:disambiguation. DMahalko (talk) 19:44, 26 March 2009 (UTC)

How does someone come directly to this article, a "data page"? Oh yeah, Electrochemical series, right? Ooops – my bad? (In my defense, I was new here.) Perhaps repoint that redirect to Standard electrode potential#Standard reduction potential table? Or perhaps just revert to have it point to the top of Standard electrode potential, as Physchim62 intended it to? — the Sidhekin (talk) 20:21, 26 March 2009 (UTC)

... or perhaps the redirect itself is okay, but as DMahalko suggests, this article could start out by telling the reader there's more basic information in the articles on the battery and the galvanic cell? Plenty options; what's good? — the Sidhekin (talk) 20:46, 26 March 2009 (UTC)

The lead of this article itself contradicts what Physchim62 is suggesting: They can be used to determine the potential of an electrochemical cell or galvanic cell... -- yet this editor says this data cannot be used for that purpose and will yield an incorrect result. Please explain the problem in the article, link to an article discussing the problem, or remove the statement that the table data can be used for that purpose. DMahalko (talk) 23:35, 26 March 2009 (UTC)

sorry when my English is poor. I'm half an expert, meaning I do it on university students level. so I need a basic table with some common data. what I found here is a complete useless table. maybe postgraduates find it appropriate, but they would have other sources. most cases there are undergraduate students, learning for tests. this field is most demanding in chemistry for a lot of people (I know cause I'm trying to teach it). I think the data actually shown here is contradictory to what you learn of textbooks. you won't even find the data of your textbook here, when trying to read here. and why it says you'd have to multiply by the number of electrons again? my textbook has sometimes the same values, but without the need of multiplying again. and I think the term electron volt maybe confusing here, meaning I don't understand it. the question is: what's the goal? if you want to show us your skills, than I'm fine with it. if the goal is a good Wikipedia article, that provides both help and knowledge than the goal is missed. again sorry for my English and sorry if you all disagree with me. just wanted to let you know Watercooled81 (talk) 18:56, 28 June 2021 (UTC)

It's sortable, so what?

I don't understand why this should be the only sortable table in Wikipedia with an user's manual. —Preceding unsigned comment added by 155.41.197.108 (talk) 23:19, 11 May 2010 (UTC)

Hydrogen Peroxide potentials

The potentials for hydrogen peroxide must be wrong (neither have citation). Combined they are equivalent to the well-known oxygen-water half-cell, but the potentials don't add up, in particular the oxygen-peroxide potential should be NEGATIVE. Does anyone have authoritative values? — Preceding unsigned comment added by Dbernat32 (talk • contribs) 07:08, 13 October 2011 (UTC)

Calomel electrode

Missing potentials for calomel electrode, saturated (S.C.E.) and unsaturated KCl — Preceding unsigned comment added by 129.7.77.140 (talk) 22:04, 1 December 2011 (UTC)

general question on data pages, downloadable as CSV and is there something like old CRC handbooks?

I pulled out an old CRC handbook from 1970's to look up colors and crystal structures of some inorganic compounds. I thought at the time it would be nice to have that in a csv file somewhere. Are those available on wikipedia? I hadn't recalled anything called a data page before but it has been a while. Data needs an API for machine access :) The US National Library of Medicine has something called PubCompound along with pubmed but I thought a simple CSV file would be nice and their DB did not seem as complete as my old CRC handbook ( at least for the compounds of immediate interest). Thanks. — Preceding unsigned comment added by Nerdseeksblonde (talk • contribs) 12 February 2012‎

This is Wikipedia, not a database. No, we don't have any reason for adding a CSV to this page. Timothy G. ^{from CA} (talk) 21:30, 18 February 2015 (UTC)

Template problem on mobile view

Some templates are wrongly displayed on mobile version of Wikipedia. Could someone check this out, examples are +1.78 and +2.09. Regards. --164.40.231.91 (talk) 16:33, 29 August 2014 (UTC)

Looks fine here. Timothy G. ^{from CA} (talk) 21:28, 18 February 2015 (UTC)

SnO2 reduction to SnO or Sn ?

The Tin(IV) oxide to Tin(II) oxide reduction equation looks wrong to me. Here is the published equation:

SnO2 + 4 H+ + 4 e- -> SnO + 2H2O

The potential is -0,09V.

Can anyone review this entry please ? Miloud90 (talk) 20:42, 1 April 2016 (UTC)

Cu²⁺ + 2e^- -> Cu(s) and Cu⁺ + e^- -> Cu(s) Potentials Reversed?

If:

Cu2+ + 2e- -> Cu(s) with a potential of +0.337V

Then the potentials of:

(1) Cu2+ + e- -> Cu+

AND

(2) Cu+ + e- -> Cu(s)

Should add up to +0.337V, right? According to this table, (1) is +0.159V and (2) is +0.520V which would add to +0.679.

Are two of these potentials reversed?

The potentials are per electron so they should add up to twice 0.337 or 0.674. PAR (talk) 15:16, 9 February 2018 (UTC)

The sentence: "The potentials are per electron so they should add up to twice 0.337 or 0.674." is definetely not consistent, because this would mean for the Daniell-element that consists of Zn and Cu2+ an electrode potential of 2.2 V would be expected, since both potentials should be multiplied by the factor of 2. This is contradictory to the observation of 1.1 V at standard conditions. Thus, the claim that the potentials have to be multiplied by the number of electrons is completely wrong and has to be removed! — Preceding unsigned comment added by 2A02:8108:50BF:9BFC:4993:D6FB:9C49:B91C (talk) 08:02, 7 May 2020 (UTC)

Xenates

I have heard that Xenates(VIII) XeO6 4- have electrochemical potentials higher than that of fluorine. Is it so? Exe csrss (talk) 15:40, 23 June 2020 (UTC)

"SEPDP" listed at Redirects for discussion

The redirect SEPDP has been listed at redirects for discussion to determine whether its use and function meets the redirect guidelines. Readers of this page are welcome to comment on this redirect at Wikipedia:Redirects for discussion/Log/2023 November 30 § SEPDP until a consensus is reached. TartarTorte 18:46, 30 November 2023 (UTC)

Pd2+/Pd 117.20.113.87 (talk) 12:50, 15 March 2024 (UTC)

Cr 2O2− 7 + 14 H+ + 6 e− ⇌ 2Cr3+ + 7H2O ; a typo?

The potential of the redox pair in the heading is reported to be +1.38 V. Most other sources report +1.33 V. In addition, the value +1.38 V does not fit in the sequence of increasing potentials reported in the table. It is likely that value is a typo. Ekisbares (talk) 15:04, 26 August 2024 (UTC)

Great catch. This error was introduced in 20:30, 1 January 2024 when we were switching sources from Lee to Atkins et al. (AS5). The typo is clearly visible in Atkins — if you average their potentials for single-electron reduction of Cr(VI) to Cr(III), you get (0.55 + 1.34 + 2.10)/3 = 1.33, which disagrees with their stated potential of 1.38 for the overall half-reaction. I've changed the source to Greenwood and Earnshaw, which has the correct value of +1.33 V. Preimage (talk) 14:58, 11 October 2024 (UTC)