Recent content by Sebi123

When the call of the 3rd party library fails, catching the most general exception, try { // something that might fail for reasons I don't want to anticipate } catch (Exception ex) { // do something } is not a bad idea, unless your system should behave differently when different exceptions...

Ah, okay: Regarding a Pt-Cu-system: With specifying the concentrations in both phases as beeing pure phases I have already "used up" both of two degrees of freedom (f = 2-2+2=2 here) and T and p would need to take on very specific values to make the system consisting of two pure phases (if such...

.. because in the derivation of Gibbs rule I know the chemical potential of each component is set equal. µPt(in Pt bar) = µPt(in copper solution) (and the same of the copper solution). But there is not Pt in the copper solution, so this kind of derivation does not make sense, I guess.

The water-example might be nonsense. But there are equilibriums with completely different chemical compositions of the phases. For example, a platinum bar immersed in a copper solution. Does Gibbs phase rule (or classical thermodynamics at all) makes a statement about such situations?

Okay, I see my error in reasoning here, thanks. So, on small scales one has phase 1: H2O(g) + O2(g) phase 2: O2(g) phase 3: H2O(l) ? And this situation is not describable by Gibbs rule, because not each component is contained in each phase (no H2O in phase 2 and no O2 in phase 3)?

Thanks so far. For the simple example it's now becoming clearer. But to be sure to really understand it: For the system with H2O(l) in which O2(g)-bubbles are dissolved in contact with H2O(g) where also O2(g) exists: Are the phases phase 1: H2O(g) phase 2: O2(g) phase 3: H2O(l) or phase 1...

Do I need to check for all conceivable changes? Or is the selection of properties application dependend? In the example above: If I'm not interested in water being either gaseous or liquid, I would say I have only one "water-phase". I think Gibbs phase rule is applicable here, because µ(T,p)...

Oh, you mean each phase must include all components? Because of the derivation of Gibb's rule, which includes chemical potential functions µ(T,p,x1,...,xr-1) (with xi: mole fraction of component i) for each phase? If this example is not possible, how about a simplified version with H2O as the...

Gibbs phase rule says f = r-M+2 with f: thermodynamic degrees of freedom; r: number of components; M: number of phases I wonder whether the definition of "phase" is restricted or almost arbitrary. For example, consider a system of H2O, O2 and H2 in a closed vessel. Let there be the...

Maybe I should rephrase the problem above. The short version is: In a reversible weight process, in which system A goes from state A1 to A2 and reservoir R from R1 to R2, the energy transferred to the weight is (W12AR→)rev = E1 - E2 + E1R - E2R = Ω1R - Ω2R This is equation 6.5 in section 6.6.4...

In what follows I refer to the ideas of "Thermodynamic: Foundations and Applications" by Gyftoploulos and Beretta. The abbreviated form of my question is: In a reversible weight process, Ω1R-Ω2R = E1 - E2 (see eqn. 6.18, p. 99) is transferred out of the composite of a system A and a reservoir R...

The statistical approach might be simpler. I wonder why the book seems not to have received that attention I thought it would have after reading the preface, where the authors say they "... have composed an exposition of the foundations and the applications of thermodynamics that many...

I find the basic idea behind the treatment of thermodynamics in the book so appealing, because everything there relies on lifting and lowering weights in a constant gravitational field. That is very intuitive and leads to an operational definition of the terms "energy" and "entropy"...

I'm reading Thermodynamics: Foundations and Applications by Gyftoploulos and Beretta, because the authors claim to give a presentation of classical thermodynamics without "... the lack of logical consistency and completeness in the many presentations of the foundations of thermodynamics" [from...