Talk:Standard electrode potential

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Contents 1 Merge/expansion 2 A question 3 Error Correction 4 Dead Link 5 Absolute potential of each half-cell? 6 E naught

[edit] Merge/expansion

I am currently working on a new version of this article at Standard electrode potential/Temp. Physchim62 (talk) 06:14, 28 November 2005 (UTC)

I agree that the two should be merged. There is little that one would want to say on either subject without a very large degree of overlap Ahw001 09:28, 26 March 2006 (UTC)

I think it's better to mantain the articles separated because many people are in confusion with the different ways to relate to the same concept. 26 august 2006

I also think they should be separated, as ORP is used as a field parameter in water quality assessment and ground water analysis. For those uses, a general definition or suggestion of implication of Eh is more important than explaining how the standard was achieved. Also, field conditions never have the standard constants, like temperature, which might throw off users of the ORP recorded in fie24.172.82.130 11:46, 11 January 2007 (UTC)ld equipment like water quality meters, etc. 24.172.82.130 11:46, 11 January 2007 (UTC)

I suggest keeping separated. I've added information regarding practical measurements of ORP, which seems like good focus for a general article on ORP, that would then link to more specific discussion of standard electrode potential. Jjotter 22:18, 2 February 2007 (UTC)

[edit] A question

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)

[edit] Error Correction

I think there is a small problem with the first line of the standard reduction potentials table displayed in this article. it says:

  F2(g) + 2e-      -->      2 F (aq)

it _should_ say

  F2(g) + 2e-      -->      2 F- (aq)

I don't know how else to edit this. sorry —The preceding unsigned comment was added by 129.105.83.220 (talk • contribs).

You are right, but I don't really have the software capable of fixing this up either. Anyone else? -postglock 14:02, 3 August 2006 (UTC)

Done. Mattiyeh 21:01, 7 October 2006 (UTC)

[edit] Dead Link

The 4th external link at the bottom on Electrochemical reactions doesn't seem to work for me, it just resturns a 404 error. Is this the same for anyone else? If so it should probably be removed. sijarvis 12:28, 3 August 2006 (UTC)

Dead link removed. -postglock 14:02, 3 August 2006 (UTC)

[edit] Absolute potential of each half-cell?

I'm changing this odd statement: there is no way to measure the individual potentials of the electrodes in isolation. There are ways to measure electrostatic potentials, but they're not simple and not very accurate. --Wjbeaty 03:07, 15 November 2006 (UTC)

With reference to what? earth? but then, whose earth? The absolute potential of a half-cell is undefined, and this has some significant implications for thermodynamics. I will invite other comments before reversing your edit, as you obviously believe what you're saying, even if I think you're wrong! :) Physchim62 (talk) 15:44, 16 November 2006 (UTC)

Earth? Huh? You do understand how the halfcell potentials are created, right? The electrolyte is a conductor, as is the metal, while the Helmholtz layer at the metal/electrolyte interface acts both as a charge pump and as a capacitor dielectric. This capacitor is charged up to a particular potential diff. This absolute halfcell potential appears between the capacitor's two plates: between the electrode and the electrolyte. Since we can't connect a common voltmeter to the electrolyte without introducing huge artifacts, a non-contact voltage measurement would be required. And these measurements aren't very accurate. But just because imprecise and exotic voltmeters are needed, that doesn't mean that the electrolyte/metal capacitor has an undefined voltage.

For example, a quick online search turns up various papers which put the absolute halfcell potential of the SHE at around 4.45v. Since chemists of the 1800s had no way to measure this value, yet had a great need to organize the list of halfcell potentials, they apparently decided to declare the SHE halfcell potential to be zero, even though it's nowhere near zero.

So, which thermodynamic implications arise if we accurately measure the value of the SHE halfcell potential? --Wjbeaty 08:52, 8 December 2006 (UTC)

[edit] E naught

Shouldn't it be an 'E' with a superscript 'o' horizontally crossed through it?

Now, you just have a superscript letter 'o'. —The preceding unsigned comment was added by 60.241.120.20 (talk) 22:54, 9 December 2006 (UTC).

Well? Does a symbol even exist for E naught? 60.241.129.19 02:38, 12 January 2007 (UTC)