Talk:Calorimetry

message: It appears the history alluded to in the article [at the bottom] is the history of a company that makes lab products, not a history of calorimetry.  In fact, when I looked at the history page, I saw almost nothing pertaining to the history of calorimetry?
Is it possible someone just wanted free advertising?  Should we snip it?
Phantym 21:24, 24 May 2005 (UTC)
thread_title:  Parr History 

message: The article currently claims
If an object is isolated from the rest of the universe, its temperature must stay constant.
I suspect this is incorrect.
If I take this small, inert rock at room temperature, and stick it far out past the orbit of Pluto, its temperature would plummet, right?
What about the heat pad mentioned in the supercooling article?
Imagine that I pull the pin from a grenade, then isolated that grenade from the rest of the universe. The temperature of that grenade rapidly rises when it eventually blows up, right?
--DavidCary 03:33, 22 September 2005 (UTC)
replies: text: Wrong --Dan|(talk) 09:37, 15 March 2006 (UTC)

text: I think DavidCary has a point, although his rock example isn't right.  I think that the missing part of If an object is isolated from the rest of the universe... is that the system must be at equilibrium within itself.  The grenade example given shows that a system that is out of equilibrium can change temperature.  Perhaps more transparently, if we imagine two reagents for a reaction seperated by a diffusive membrane, if we place this system in a calorimeter, it will naturally change temperature (assuming the reaction is exo/endo-thermic).  Isothermal titration calorimetry for instance requires heat to be transfered between the system and a resevoir in order to keep the temperature constant.  Remember that energy is conserved, not temperature. Zvsmith 16:08, 12 December 2006 (UTC)
thread_title:  temperature of an isolated object 

message: If a system has several energy states at a given temperature, calorimetry can be used to dissect the number and energy of the different states, right? That would be a nice thing to add here. --Dan|(talk) 09:38, 15 March 2006 (UTC)
thread_title:  Calorimetry of a 'multi-state' system? 

message: Any objections if I add a paragraph on flow calorimetry? I'll put a draft in discussion, or on my talk page before adding it. Alanf777 (talk) 18:04, 28 November 2011 (UTC)
replies: text: No objection from me. Sounds good. Reliable sources. Here is good page for discussion.Chjoaygame (talk) 21:41, 28 November 2011 (UTC)
replies: text: I decided I didn't know enough about it! 71.139.166.65 (talk) 21:06, 23 January 2012 (UTC)
replies: text: Well, that you are able to say that you don't think you know enough about it, that tells me you are likely to be a good scientist and editor. I look forward to your work when you are ready.Chjoaygame (talk) 22:31, 23 January 2012 (UTC)
thread_title:  flow calorimetry 

message: I undid this good faith edit. It was too specialized for the place where it went in the lead. Besides constant pressure calorimetry, there are also forms of calorimetry with constant volume, and with constant temperature.Chjoaygame (talk) 18:11, 21 October 2015 (UTC)
thread_title:  undid good faith edit: reason 

message: I think the new section of the present article is OK now. I am not sure what you mean by the heat-or-reaction task. If you mean the Hess's law article which we were discussing above, I have just added a sentence linking it to the present article, so that readers of Hess's law can find the experimental details here. Dirac66 (talk) 02:00, 2 November 2015 (UTC)
replies: text: I mean that a heat of reaction is a special kind of latent heat. It isn't conjugate with an ordinary heat capacity. An ordinary heat capacity tells you how much heat is needed to change the temperature without such special effects as phase change or chemical reaction, and without a specified kind of mechanical change, such as for example, without pressure change. The present article on classical calorimetric theory, pre-thermodynamic, talks about the latent heats that are, you might say, conjugate with such ordinary heat capacities. For example, one could, at constant temperature, find the infinitesimal heat transfer needed for an infinitesimal volume change at near enough a specified pressure. Heats of reaction are not described by such mechanical latent heats. This present calorimetry article says nothing about heats of reaction and so is useless for those interested in Hess's law. This is a grave defect, and its remedy a significant task. At least, I think so.Chjoaygame (talk) 02:44, 2 November 2015 (UTC)

text: Hess's law is about heats of reaction. They are latent heats. That is why the Hess's law heats must have fixed common end-point temperatures: to make them latent. They can have either common end-point volumes (internal energy formulation) or common end-point pressures (enthalpy formulation), at the experimenter's pleasure or convenience.Chjoaygame (talk) 03:25, 2 November 2015 (UTC)
replies: text: There is more about the measurement of heats of reaction in the complementary articles Calorimeter and Reaction calorimeter. These two articles are more focussed on devices. Dirac66 (talk) 11:53, 2 November 2015 (UTC)
thread_title: heat of reaction

message: A few month ago, i created the article Richmann's law, which was the first equation for calorimetric calculations and should therefore be mentioned here. My english is to bad, to write in a proper scientific language. Maybe someone else can implement it and double check the new article. Thank you and greetings from german wikipedia. LukeTriton (talk) 06:13, 31 January 2023 (UTC)
thread_title:  [[Richmann's law]]