Below are the questions, organized by theme, motivating my second book, whose objective is to explore the cause-effect link between atomic interactions and thermodynamic phenomena described by classical equations.

Each question links to a page with more details, including my unverified ideas for answers. If you have your own questions or if you know the answers to any of these questions, please contact me.

Note: “Explain:” is shorthand for, explain the underlying physical cause of the following effect based on the micro-world of moving and interacting atoms.

Note: “Done” does not mean I’ve answered the question to meet my satisfaction. It simply means that I’ve shared as much as I know about the question and have hit a brick-wall.

My Unanswered Questions (MUQ)

The Kinetic Theory of Gases

• Adiabatic compression. Why doesn’t the speed of the piston matter? (Done)

Intermolecular Interactions – attraction and repulsion

• Explain: Joule-Thomson effect (Done) Addition: Intermolecular interactions naturally play a role but I’m not sure repulsion does.
• What causes a gas to deviate from ideal behavior? (Done)
• How is it possible for the compressibility factor (Z) to be greater than 1.0?
• Why does supercritical occur? What is it that prevents a gas from condensing once temperature reaches the critical point?
• Explain the Joule experiment in which he depressurized gas into a vacuum and observed that “The pressure vessel cooled a bit and the vacuum vessel heated a bit.” (Done)

Impact of gravity

• Is the temperature profile in a vertical column of gas isothermal or gradient? (still working this) More on this here: https://chatgpt.com/s/t_68c47b4b8a708191aff32647a667ab03
  https://chatgpt.com/s/t_68c47b6a17e0819183dcffed500bba43
  
• Why do balloons rise? (still working this – density gradient issue)

Flowing systems

• Explain: Isenthalpic flow
• Explain: Bernoulli equation
• Explain: Sonic flow
• Explain: Velocity of sound
• How does propulsion work?

Entropy

• Explain: Entropy trends in the Periodic Table
• The Sackur-Tetrode equation quantifies absolute entropy and does not depend on history while the integral of dQ/T from absolute zero to the reference temperature does. How is this possible?

Phase equilibrium

• Explain: Clausius-Clapeyron equation (Done)
• Why was Gibbs’s phase rule so impactful on the work of Roozeboom?
• What are the physical criteria governing reaction spontaneity for both isolated and constant T,P systems?

Chemical reaction

• What are the different ways that heat effects can occur?
• What is the sequence of physical steps that occurs during a chemical reaction that results in heat effects?
• Chemical reactions: what are the physical meanings of dH, dG, and dS?
• Is the dS of reaction a unique function of temperature, and conversely, is temperature a unique function of dS?
• Is spontaneity always defined by a 2nd law that states, a system of particles always moves to the most probable distribution?
• Does the most probable distribution take precedence over dS > 0?
• Explain: Reaction equilibrium
• What is the role of electron re-arrangement in quantifying dS reaction?
• Does combustion destroy exergy? (Pending – preparing publication on this)

Photons

• What events cause photon emission/absorption?
• How does photon absorption heat matter? How does photon emission cool matter?
• Explain: the Stefan-Boltzmann T^4 Law

General

• Do we define thermodynamic quantities based on the effect they cause, i.e., PE<->KE transformations?
• Why is heating with electricity inefficient?
• Thermo tells you wether or not something is possible. Engineers tell you whether or not something possible makes economic sense or it practical. Bill Banholzer.
• Heat Capacity: we use “specific heat capacity” because it’s easy to weigh something. This is what Joseph Black did. But this creates confusion on a per-atom basis, what’s the answer? “The higher the degrees of freedom, the higher the energy for a given temperature.” Modify Chapter 3 according to this.
• Does everything resolve with temperature or with relative speed? Velocity; LJ; critical properties; reduced properties. EOS, MB distribution, Model single past stationary? Density.
• Clarify why the Boltzmann distribution is based on energy and not some other property. More on this here: https://chatgpt.com/s/t_68c47bdba338819199999dab72f49e06
• Can’t do work with temperature. Need to transform to pressure, and pressure to force. How efficient is this transformation. And if temperature to work is possible (list ways to do this), how efficient? Consider photons (Sun) to work as well, re Martin!
• Are there short books I can write on narrow aspects of thermodynamics? Consider generating 10 ideas.
• Gibbs-Helmholtz and the relation between dG and dS for a chemical reaction. Is it the vibrational mode that’s the connecting key? Not rotation, not translation, but vibration. The stronger the vibration, the what? Happens happens to the reaction when vibration increases What does deltaS tell us about vibration? Or is this a correlation argument, with some underlying driver, rather than causation. Follow-up with Ari, yet again.

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