Ideal mixing is not associated with enthalpy/volume or heat capacity changes but is controlled by only entropy changes. The practical examples ideally mxiing are close isomers, e.g., n-propanol and i-propanol, xylenes, and so on, but even the substances from the same homology, i.e., n-propanol and n-butanol; perhaps some optical isomers, and of course the compounds differing in isotopic substitution.

Multiple dissolution or adsorption processes of really different systems may be associated with the enthalpy close to zero even in non-ideal systems due to complexed overlapping of interactions, like competition at bining sites and solvation in a bulk solution.

In principal, a chemical reaction, for each you know the enthalpy change and heat capacity change, might be characterized by a temperature at which enthal[y became zero...

Ideal mixing is not associated with enthalpy/volume or heat capacity changes but is controlled by only entropy changes. The practical examples ideally mxiing are close isomers, e.g., n-propanol and i-propanol, xylenes, and so on, but even the substances from the same homology, i.e., n-propanol and n-butanol; perhaps some optical isomers, and of course the compounds differing in isotopic substitution.

Multiple dissolution or adsorption processes of really different systems may be associated with the enthalpy close to zero even in non-ideal systems due to complexed overlapping of interactions, like competition at bining sites and solvation in a bulk solution.

In principal, a chemical reaction, for each you know the enthalpy change and heat capacity change, might be characterized by a temperature at which enthal[y became zero...

Intra-molecular H-binding is always favored with respect to inter-molecular H-bonding due to entropy factor (neglecting solvent interaction).

Micelle formation is driven by entropy.

Article Use of Isothermal Titration Calorimetry to Study Surfactant ...

Is there a reasonable interdisciplinary argument for the second law of thermodynamics?

1. There are many kinds of type 2 perpetual motion machines. Behind each type is a natural phenomenon.Machine A: against the irreversibility of thermodynamics (diffusion, heat conduction, friction, etc) - dynamics;Machine B: Utilizing the Difference of Carnot Efficiency (Reversible Thermodynamics) - Thermodynamics

2. A and B belong to different disciplines. There is a parallel relationship between them, and there is no logical mutual inevitability.Logic of Law 2 of Thermodynamics: Experience induction, denying that A machine==》 B machine can not be manufactured==》 All material Kano efficiency: 1-T1/T2.

3. The logic of the second law of thermodynamics violates the physical logic that A and B cannot deduce from each other.

4. The second law of thermodynamics elevates the "irreversibility", which is only a dynamic experience.

5. See the picture below for details.

As pointed out by Mikhail, I doubt that some reaction may be exactly "zero - enthalpy" or "athermic". On the other hand, reactions essentially driven by entropy are probably numerous. For example, the enthalpy of acid dissociation of substituted benzoic acids in water are very small (even difficult to measure) and that the Gibbs energy of dissociation in water is governed by entropy.

The so-called "entropy " doesn't exist at all.

During the process of deriving the so-called entropy, in fact, ΔQ/T can not be turned into dQ/T. That is, the so-called "entropy " doesn't exist at all.

The so-called entropy was such a concept that was derived by mistake in history.

It is well known that calculus has a definition,

any theory should follow the same principle of calculus; thermodynamics, of course, is no exception, for there's no other calculus at all, this is common sense.

Based on the definition of calculus, we know:

to the definite integral ∫T f(T)dQ, only when Q=F(T), ∫T f(T)dQ=∫T f(T)dF(T) is meaningful.

As long as Q is not a single-valued function of T, namely, Q=F( T, X, …), then,

∫T f(T)dQ=∫T f(T)dF(T, X, …) is meaningless.

1) Now, on the one hand, we all know that Q is not a single-valued function of T, this alone is enough to determine that the definite integral ∫T f(T)dQ=∫T 1/TdQ is meaningless.

2) On the other hand, In fact, Q=f(P, V, T), then

∫T 1/TdQ = ∫T 1/Tdf(T, V, P)= ∫T dF(T, V, P) is certainly meaningless. ( in ∫T , T is subscript ).

We know that dQ/T is used for the definite integral ∫T 1/TdQ, while ∫T 1/TdQ is meaningless, so, ΔQ/T can not be turned into dQ/T at all.

that is, the so-called "entropy " doesn't exist at all.

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.

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Why did the wrong "entropy" appear ?

In summary , this was due to the following two reasons:

1) Physically, people didn't know Q=f(P, V, T).

2) Mathematically, people didn't know AΔB couldn‘t become AdB directely .

If people knew any one of them, the mistake of entropy would not happen in history.

Please read my paper and those answers of the questions related to my paper in my Projects.

https://www.researchgate.net/publication/230554936_Entropy_A_concept_that_is_not_a_physical_quantity

Shufeng Zhang 你能否发一份中文的论文附件在下面，我想阅读一下。

So Gibbs energy doen't exist ?

Bo Miao,

如果把中文版论文全文发到这里可能会变形，恐怕看起来很吃力。

Bo Miao,

你可以在网上搜一下，"熵：一个不是物理量的概念"，有中文版，我在一些论坛和文库类网站发过很多版本，跨度很多年，应该可以找到最后发表的那个版本。如果找不到可以发Email给我。

Bo Miao,

如果找不到，我可以考虑把中文版上传到我的“research items".

Dear Jean-François Gal,

Gibbs free energy doesn't exist.

All contents (theories, etc.,) that must use " thermodynamics entropy" don't exist.

Logical error of the second law of thermodynamics:

1. There are many kinds of type 2 perpetual motion machines. Behind each type is a natural phenomenon.

Machine A: against the irreversibility of thermodynamics (diffusion, heat conduction, friction, etc) - dynamics;

Machine B: Utilizing the Difference of Carnot Efficiency (Reversible Thermodynamics) - Thermodynamics

2. A and B belong to different disciplines. There is a parallel relationship between them, and there is no logical mutual inevitability.

Heat 2 Logic: Experience induction, deny that A machine==》 B machine can not be manufactured==》 All material Kano efficiency: 1-T1/T2.

3. Logical of the second law of thermodynamics violates the physical logic that A and B cannot be inferred from each other.

4. the second law of thermodynamics elevates the "irreversibility", but it is only a kinetic experience.

5. See the annex for details.

Thanks to all for your replies. Aside from the discussion about the existence of entropy, I think that some nice examples of entropy-driven processes have been laid out.

1，Charge moves Brownian in the container.

2，The electric field in space varies. There is an inductive current on the nearby conductor.

3，The temperature of the conductor increases, while the temperature of the container A decreases.

4，This is inconsistent with the second law of thermodynamics. Is the second law of thermodynamics correct? Judge for yourself.

See pictures for details.