Talk:Clausius–Clapeyron relation

message: A diagram like the one at http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/pvtsur.html would really help understanding for this article. Also, the "important points" at the end of http://www.eng.usf.edu/~campbell/ThermoI/Proptut/tut8frm.html would be complimentary to such a diagram.ChrisChiasson 04:00, 17 October 2007 (UTC)
replies: text:  I do think a better diagram would help people visualize the relationship.  However, the one in the article and the ones referenced above are general diagrams of phase equilibrium curves, rather than diagrams actually showing the particular equation/relation which this page is about.  Such a diagram would actually show a tangient drawn at a few locations and show how the other side of the equation arrives at the slope value. (71.233.167.118 (talk) 02:28, 31 August 2013 (UTC)
thread_title: Diagram request

message: That example may be correct, but it's a pretty poor illustration of the concept.  You don't even say where you got all of the variables.
: The variables don't matter (they are, however, reasonable).  It's an example of how to use the equation in the sort of problem that a student is likely to encounter.  While obviously I haven't sampled a statistically significant number of thermodynamics courses, both of the ones I've done (at different universities) have used problems similar to that, and hence I think it would be beneficial to a great many users.  Far too many physics and maths articles, in my opinion, present a technically correct but utterly arid explanation which is of practically no use to understanding the concepts involved.  Students who actually have to use the Clausius-Clapeyron relation in an assignment will be grateful for the example, and other users won't care.  It certainly doesn't detract from the article from a practical point of view.  Ckerr 20:35, 8 July 2006 (UTC)
thread_title:  Lose the ice skating example! 

message: The ice-skating example doesn't agree with what ice ice skating says about ice's sliperyness.—Ben FrantzDale 17:19, 6 July 2006 (UTC)
replies: text: Yes, it does, actually.  It says: "the precise mechanism by which the low-friction is generated is not fully understood, though a number of plausible theories abound usually involving explanations of air-ice boundary layer water and/or friction generated through the skate bottom."  Nothing about pressure.  As a result I'm reverting the edit.  Look, I'm not opposed to the idea of having a disputed tag if it can actually be shown to be in dispute.  But since you appear to be mistaken (this article is consistent with the ice skating article), and since all other people who have criticised the ice skating example have failed to answer my replies, I don't believe--yet--that it's warranted.   Ckerr 20:35, 8 July 2006 (UTC)
thread_title: Dubious

message: I think this article actually discusses the Clapeyron equation.  I think the Clausius-Clapeyron equation is an approximation (based on the Clapeyron equation) for liquid-vapor (and perhaps solid-vapor) equilibrium assuming various things (e.g. ideal gas vapor and negligible liquid (or solid?) volume). See, for example, , , and .--GregRM 00:02, 14 July 2006 (UTC)
replies: text: It appears there are several different conventions in use.  I have never heard of it referred to as the "Clapeyron equation" until now, and I checked the original sources I used when writing this article, and they do refer to the equation given (dP/dT=L/TdV) as the "Clausius-Clapeyron equation".  Perhaps a vote could determine which convention is more widespread, but I think whichever is chosen, both terms should redirect to the same page. Ckerr 03:45, 14 July 2006 (UTC)
replies: text: The textbook Introduction to Chemical Engineering Thermodynamics (6th ed.) by Smith, Van Ness, and Abbott makes a distinction between the exact equation (which it calls the Clapeyron equation; it is equivalent to the one discussed in this article) and the approximate equation (which it calls the Clausius/Clapeyron equation; it seems to be equivalent to the one discussed in Clausius-Clapeyron equation (meteorology)). I just looked at my physical chemistry text (Physical Chemistry, 5th ed. by Ira N. Levine), and it claims that according to most texts for physical chemistry, the approximate equation is referred to as the Clausius-Clapeyron equation. It goes on to say, however, that the exact equation is called the Clausius-Clapeyron equation in most texts for engineering thermodynamics and physics. (On the previous page, discussing the exact equation, the book said the exact version was called the Clapeyron equation, but said that it was also known as the Clausius-Clapeyron equation.)  Thus it seems that the term "Clapeyron equation" refers to the exact equation, but the exact equation is not always called the Clapeyron equation (it may be called the "Clausius-Clapeyron equation").  Likewise, it seems that when it is named, the approximate equation is always called the Clausius-Clapeyron equation, but the term "Clausius-Clapeyron equation" does not necessarily refer to the approximate form (it may refer to the exact form). I prefer the scheme of calling the exact equation the Clapeyron equation and the approximate equation the Clausius-Clapeyron equation, since it provides an easy distinction between the exact and approximate equations. The best solution may be to explain the different usages in the article, and perhaps use disambiguation header or redirects (as you suggested).--GregRM 23:09, 20 July 2006 (UTC)

text: If you could provide these references, I will add them to a disambiguation section. Before I read your paragraph, I was about to propose renaming this article...ChrisChiasson 10:17, 11 October 2007 (UTC)
replies: text: If you don't provide the references soon, I am probably going to change the article to match my two thermodynamics text references and one online reference (the arizona state one mentioned at the bottom of the article). ChrisChiasson 16:29, 16 October 2007 (UTC)
thread_title:  Requested move / Clapeyron equation 

message: Although not subscribing to the hypothesis of global warming as pinko-communist propaganda, the meteorology section is poor.  The notation is inconsistent with that used elsewhere, units are abused and even if the discussion can be backed with serious references, the issue of runaway global warming is not notable in the context of this particular article.  It's also appropriate to note that just because exp features in an equation, the overall behaviour does not have to be "exponential" in the sense of runaway. Pdch (talk) 23:26, 2 January 2008 (UTC)
replies: text: The formular for the water vapor pressure does not explain the units and the range for which this formular is a good approximation.  According to  the pressure is given in hPa, and temperature is given in deg. Celsius. Though slightly different numbers are given, possibly due to a different temperature range for very good accuracy. So someone should check the numbers and the corresponding range for which the Coefficients are optimized and how far the formular is valid. --Ulrich67 (talk) 16:26, 9 September 2012 (UTC)
thread_title:  Meteorology 

message: I removed the negative sign in the two point form; it should be positive. (Unless my AP chem textbook is completely wrong)  —Preceding unsigned comment added by 67.81.71.135 (talk) 23:30, 5 January 2009 (UTC)
thread_title:  Two-point form 

message: I found a good little guide from an .edu on applying the Clausius-Clapeyron relation, I'm not sure whether its appropriate to create an external link section, add to the article as a reference, or just leave her on the talk page, so I thought I'd put it up here first. 
http://itech.pjc.edu/tgrow/1046/chm1046cceq.pdf
--Pstanton (talk) 07:02, 28 January 2009 (UTC)
thread_title:  Guide for the Algebra