Thermodynamics Definition and 1000 Threads

In the chemical engineering text of Smith, VanNess, and Abbott, there is a section on partial molar volume. It states that Gibbs theorem applies to any partial molar property with the exception of volume. Why is volume different? In other words, when evaluating the partial molar volume of a...

Suppose we have a body that isn't a black body, but has an arbitrary emission spectrum. In the general case, can the radiation from this body be characterized as having a temperature, and if so, how? If not, what conditions are needed to make the concept of temperature meaningful in this case?

In thermodynamics, the internal energy (U) is the function of the volume (V) and temperature (T), U = U (T). Therefore, according to the mathematics, dU = π dV + Cv dT, where π is internal pressure and Cv is the constant volume heat capacity. Meanwhile, according to the 1st law, dU = δ w + δq...

as it is not ideal, total change of entropy > 0 entropy loss of hot reservoir > entropy gain of cold reservoir why would the change in entropy of the heat pump in one cycle equals to zero? thank you

I tried modeling the problem quite a few ways. one was to say that the difference between the heat emitted by the room and the heat emitted by the bulbs would equal the heat absorbed by the room, and that could allow us to calculate temperature. This did not work. I'd appreciate your help

Question (These are incorrect values) Attempt I used and then found the respective change in temperature. However for the last question I have no idea, do I sum up the net change in temperature and use But then what is the work and how do we figure it out?

I tried this... but I'm not sure if I'm doing it right or maybe there's a simpler way. Thanks for your time or help :) The fundamental relation is: $${S \over R} = {UV \over N} - {N^3 \over UV}$$ but I used $$s=S/N, u=U/N, v=V/N$$ to obtain $${s \over R} = uv - {1 \over uv}$$ then I did...

Carnot's postulate: one cannot build an engine whose sole effect is to transfer heat from a cold body to a hot body. How granted this postulate can I prove that no engine beats Carnot's engine? From this postulate, I can conclude that work must be done from the surroundings and that Carnot's...

I actually can't figure out what kind of phase transition it is and how to proceed through..!

Summary: The transition Sn(s, gray) ⇌ Sn(s, white) is in equilibrium at 18°C and 1 atm pressure. If ΔS = 8.811K mol for the transition at 18°C and if the densities are 5.75 g/cm3 for gray tin and 7.28 g/cm3 for white tin, calculate the transition temperature under 100 atm pressure The...

Problem Statement: A monatomic ideal gas expands from 100cm³ to 200cm³ at a constant pressure of 1.0 × 10⁵ Pa. Find the change in the internal energy of the gas. Relevant Equations: Included in my attempt at a solution

I'm taking an online course that covers the Rankine power cycle, that, unfortunately, isn't mentioned in any of my textbooks. Do you guys have a textbook that covers this cycle? Thanks

Consider a system composed of a gas+stirrer at state 1, Work is done on the system by a rotating shaft, the stirrer activates high speed generating a significant amount of heat. The system is undergoing a process because the set of measurable properties to define its state are changing, If I...

assume I have 3 systems a,b and c. the equilibrium between a and c can be described by the equality PcVc = f(A1,..., An) and the same for b and c - PcVc = g(B1,...,Bk). why does the equality g(B1,..., Bk) = f(A1,..., An) describes an equilibrium between A and B? the 0th law states that if A and...

Hi, so I found this on another old "AP" High School Finals Exam. I think I may be super lost. Because the only way that I can think about is KE = 3/2kT. And then that the difference of the Kinetic Energy of the air Particles is the Q supplied by the heater inside the air dryer. So ## \frac...

There was a time when they didn't believe in atoms. But thermodynamics and temperature still existed and applied. What are the ways that atoms can influence thermodynamics? I can only think of one now where the temperature of the nuclear warhead suddenly increased million folds due to the chain...

How would the first and second laws of thermodynamics apply to the creation and existence of the universe? I'm not a physicist (and unfortunately, do not remember a lot that I learned in Physics class in school and college about Thermodynamics). I did some searching and I have come across an...

I have a 30 by 30 shop with insulation and 10 foot ceilings. I have been reading about geothermal and it got me curious. If I were to bury 1 inch PVC type pipe and ran water and radiator fluid or water and some type of alcohol like windshield washer fluid is there a formula to determine the...

The text says: "Steel bullet of 25kg with a Temperature of 400 Celsius, is being dropped on the bottom of an oil liquid of 100kg at a temperature of 100 Celsius. The system is isolated. Calculate a) The change of entropy of the bullet, b) the change of entropy of the oil, c) the total change of...

I don't know how to make the practical or what practical I can conduct that would test the question we have been given.

An ideal diatomic gas undergoes an elliptic cyclic process characterized by the following points in a ##PV## diagram: $$(3/2P_1, V1)$$ $$(2P_1, (V1+V2)/2)$$ $$(3/2P_1, V2)$$ $$(P_1, (V1+V2)/2)$$This system is used as a heat engine (converting the added heat into mechanical work). Evaluate the...

I have a feeling some integration will be required, I just want to see if anyone know of a quick way.

Problem Statement: 1 kg of water at 273 K is brought into contact with a heat reservoir at 373 K. When the water has reached 373 K, what is the entropy change of the water, of the heat reservoir, and of the universe? Relevant Equations: dS=Cp*(dT/T)-nR*(dP/P) dS=Cv*(dT/T)+nR*(dV/V) I am...

So, for the end of this semester's introductory couse in General Relativity (undergrad) I have to do a project on "The analogy between the mechanical laws on a black hole and the laws of thermodynamics". I couldn't find much (at least on my own) about this particular topic in my university's...

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We know from first law of thermodynamics for a closed system that ##dE##=##\delta Q## -##\delta W## , my question is that for a closed adiabatic system net heat transfer =0 this mean net change in energy = work done , does that mean for an adiabatic system work done is a point function as...

The multiplicity of states for a particle in a box is proportional to the product of the volume of the box and the surface area of momentum space. $$ \Omega = V_{volume}V_{momentum}$$ The surface area in momentum space is given by the equation: $$p^{2}_{x}+ {p}^{2}_{y}+{p}^{2}_{z} =...

The second law of thermodynamics tells us that the amount of useful energy in an isolated system tends to decrease. Does this imply that mankind will reach a point where it cannot longer use any kind of energy? If so, do we have an estimate of how long it will be necessary for to haven't useful...

The first law of thermodynamics states that matter can only be transferred from one state to another, and cannot be truly destroyed. What happens to matter consumed by a black hole? What happens to it and where does it go? Does the first law still hold true?

Hi, I am doing a level 3 engineering diploma, myself and the rest of my class are struggling to answer most of the questions on the attached assignment paper particularly questions 2, 4, and 6 and 7. I have worked out q1 to be 7.3 icebergs per year needed and 7.3 x 10^3 volume needed. Most of...

Hello, I am beginning a course in thermodynamics in which we will be using the textbook "Fundamentals of Engineering Thermodynamics" (Moran, Shapiro Et al.). Does anyone know of a video series which covers similar topics as in textbook? I have the textbook, I am just looking for a supplement...

(a) My question : Are all the formulas correct? If so I can write ##v_{rms}## in form (2) and compare that result with the other velocities to get the answer (rms > average > most probable)

Hello, Just like the title suggests, I am looking for DIY project ideas, that involves Thermodynamics, Robotics, and Artificial Intelligent. I would like to use C++ and Simulink. And I am able to purchase components, e.g. Raspberry Pi and electrical components. If you have any ideas for a...

Hello there, So yesterday my thermodynamics professor did some black magic and transformed our beloved equation (1/(1-n))*(p1v1-p2v2) into (n/(n-1))*(p1v1-p2v2), but i didnt understand why he did it and how (he is too fast for my writing). Does anyone know how he did it, are there any...

Precursor : Sign conventions regarding Work by the system/on the system may even vary among Physics textbooks and among Chemistry textbooks and as a rule of thumb it is better to clearly mark out the convention used by the text being referred to specifically and remain consistent with it...

Zemansky defines Heat as : When a closed system whose surroundings are at a different temperature and on which diathermic work may be done undergoes a process, then the energy transferred by non mechanical means, equal to the difference between the change in internal energy and the diathermic...

A well-type mercury manometer has a well of 0.02m^2 area and a tube of 40mm^2 area. The liquid has a density of 13,534 kg/m^3.Given that the tube is open to the atmosphere and the well is connected to the inert gas manometer was to measure: Calculate the pressure of the inert gas in kN/m^2 if...

I'm having trouble wrapping my head around some thermodynamics and ideal gas law concepts. I don't have a specific textbook question but Just a concept I'm having trouble with. What I'm struggling with is understanding some of the relations between pressure, volume and temperature...

in Clausius formulation, what does the phrase "from cold to hot" means? I can understand it intuitively but in the language of the zero and first laws, we have not defined a temperature scale, only equivalence classes of systems that will be in equilibrium with each other (systems with the same...

Looking for thorough serious comparative review of modern generalisations of classical non-equilibrium thermodynamics of continua. I have heard about several such generalisations: 1) rational mechanics by Truesdell, Coleman, Noll. 2) extended thermodynamics by Müller (and Ruggeri). 3) the...

I would like to ask a question on whether there is a proportionality between volume of a balloon, and the time it takes to deflate. I have conducted several balloon hovercraft experiments. I need to find the relationship between the amount of air pumped into the balloon and how long the...

Hi there, I'm trying to design an ion beam source, but having some issues with the thermodynamics of it. I'm no expert in thermodynamics, but I do understand some. I'm trying to find an equation which I can use to find the amount of energy I need to put into a set mass of a set material in order...

So, I converted the V (milk) to m3 and found 1.8E-4 m3 and i already know the density so i found the mass of the milk in the bottle. Mmilk= 1.9E-7 kg Normally i would try to connect it with the formulas above but i don't know temperature. I am not sure how i can connect the dots. Can...

Hey guys, Have a thermodynamics exam coming in the next few days up based on the following topics. Energy and first law, Thermodynamic properties, First law: closed systems, First law: open systems/specific heat. When I have taken a look at the past exams it has been all calculations and...

Relevant Equations: Specific Work Done: w = \frac{p_2 v_2 - p_1 v_1}{1-\gamma} (1) w = \frac{R}{1-\gamma} \times (T_2 - T_1) (2) Thermal efficiency: \eta _{th} = 1- \frac{1}{r_p ^ {\frac{\gamma - 1}{\gamma}}} = \frac{w_{out} - w_{in}}{q_{in}} = \frac{q_{out} - q_{in}}{q_{in}} (3) Context...

Hi all, I have had the following question in my head for quite a while: Thermodynamic potentials written in differential form look like $$dU = TdS - PdV$$ and we can obtain equations for say, temperature by doing the following partial $$T = \frac {\partial U}{\partial S} |_V$$ Does this mean...

Hi every one , I have this question today : The two arrows in the figure show two thermodynamic processes of a certain amount of ideal gas. The dashed line is a hyperbola. Which of the following statements is not true? a. The heat transfer is the same in the two processes. b. The temperature...

WT, the work done by the turbines, as the difference in enthalpy from point 2 to point 3 WP, the work done by the pumps as the difference in enthalpy from point 4 to point 5 Q as the difference in enthalpy from point 3 to point 4 Taking these I get h5 = -252.3kJ/kg. However, my work ratio is...

let's assume I have 2 systems A and B. the surface that describes when the 2 systems are in equilibrium is given by F(a1,a1,...,b1,b2,...) = 0. assuming we can write this surface as A(a1,a2,..)=B(b1,b2,...) why do A and B describes the temperature function of the systems? in class, we...