Thermodynamic Definition and 502 Threads

Homework Statement Specify at least two ( physical or chemical), real world, processes for each of this cases: a) Internal energy is constant b) Entalpy is constant c) Gibbs free energy is constant d) Helmholtz free energy is constantHomework Equations a) dU = TdS - pDV = 0 b) dH = TdS...

Homework Statement 4 liters of an ideal diatomic gas are compressed in a cilinder. In a closed process, the following steps are taken : 1) Initial state : p_1 = 1 atm = 1.013*10^5 N/m^2 and : T_1 = 300 K 2) Isochoric proces resulting in : p_2 = 3.p_1 3) Adiabatic expansion resulting in...

Homework Statement The rate of heat loss to the outside through a 10mm-thick glass roof of a green house is 120kW. The length and breadth of the glass material of the roof are 20m and 2m, respectively. Calculate the temperature of the outside if the temperature inside the green-house is 25...

Homework Statement Two moles of an ideal monoatomic gas trebles its initial volume is an isobraic expansion from state A to state B. The gas is then cooled ischorically to state C and finally compressed isothermally until it returns to state A. The molar gas constat is: R = 8.314 J mol^-1...

Homework Statement The Gibbs free energy of benzene decreases continuously with temperature (at fixed pressure) and shows three nearly linear segments corresponding to the solid, liquid and gas phases. The magnitude of the slopes increases as one moves from solid to liquid, and liquid to...

Homework Statement Two moles of an ideal monoatomic gas trebles its initial volume in an isobaric expansion from state A to state B. The gas is then cooled isochorically to state C and finally compressed isothermally until it returns to state A. The molar gas constant is R = 8.314 J mol–1...

Homework Statement I can't aolve the following question: Two moles of an ideal monoatomic gas trebles its initial volume in an isobaric expansion from state A to state B. The gas is then cooled isochorically to state C and finally compressed isothermally until it returns to state A. The...

Alright, I'm confused about why thermodynamic cycles can never have 100% efficiency. There reversible processes right? And a reversible process has zero change in entropy, so then why can't they achieve 100% efficiency. I thought entropy was the measure of energy that cannot be used. How would...

what is thermodynamic potential?

Hello! Here is an equation that i sometimes use in calculating enthalpy of reaction aA+bB=cC+dD. a,b,c and d are stoechiometric coefficients, A,B,C and D are chemical compounds in reaction. They say that is an other form of the third law of thermodynamic, can one guide me please to derive it...

Homework Statement http://www.docstoc.com/docs/14364187/Heat_-Temperature_-Thermodynamics-and-Heat-Engines-Problem-Set This question I am trying to figure out is Number eight with the four cylinders. Homework Equations P=F/A PV=nRT The Attempt at a Solution I'm stuck at trying to...

Why is it that the The fundamental thermodynamic relation dU = Tds - PdV works in general even though Tds > dQ for irreversible processes. Likiewise PdV >/= dW for irreversible processes. Do the two irreversible effects cancel out. How does this happen physically.

Homework Statement To state the differential form of the Helmholtz thermodynamic potential and derive the corresponding Maxwell's relation. Homework Equations Stated within the solution attempt. The Attempt at a Solution Helmholtz function: F = U - TS Calculating the...

Homework Statement I. Finding the partition function Z. II. If the middle level (only) is degenerate, i.e. there are two states with the same energy, show that the partition function is: Z = (1+exp(\frac{-\epsilon}{k_{B}T}))^{2} III. State the Helmholtz free energy F of the...

Im looking for thermodynamic properties of seawater, especially specific heat and enthalpy. I am designing a solar desalinator, and I am trying to determine the required amounts of energy to evaporate the water. Is there a way in which I can determine the enthalpy of seawater by knowing the...

Homework Statement A monatomic ideal gas is compressed adiabatically from a pressure of 1.19e5 Pa and volume of 250 L to a volume of 32.0 L.(a) What is the new pressure of the gas in Pa? (b) How much work is done on the gas?Homework Equations I know that W= Average P (Delta V) The Attempt at...

Homework Statement A cylinder with a piston contains 0.250 moles of oxygen at 2.40 * 10^5 Pa and 355K. The oxygen may be treated as an ideal gas. The gas first expands isobarically to twice its original volume. It is then compressed isothermally back to its original volume, and finally it is...

Hello! Does anyone have a free ebook of Chemical Thermodynamic by Peter Rock A.?

http://arxiv.org/abs/1001.4090"

Hello! I am doing an investigation on thermodynamic propeties of certains heavy ions "Alkali-Cloride" ions on the basis of mass spectroscopy and quantum mechanical calculations. For that i use GAMESS as a computer tool to study quantum mechanical properties of those ions (vibration frequency...

if i have calorific value of mixture, volume at time of compression, bore diameter, can i know the pressure being exerted on the pistons due to the combustion?

Hello! I would like to ask anyone who can have documents about the thermodynamic properties of CsCl, Cs2Cl+, CsCl2-,Cs3Cl2+,Cs2cl3- to send me the links please. or anything else that can be related to thermodynamic properties of heavy ions. Actually i want to make a research on their...

Homework Statement This is my problem: i have a container with humid (say psi = 60%) air at a pressure of 450 bar. i need to know to what preesure can this air be expanded (adiabatically) so that it reaches temperature just above freezing. i also need to know how much work is extracted from...

The probability distribution for some thermodynamic variable x is given by P = N e^{-A(x)/KT} where A(x) is the availability, which can be replaced by Hemlholtz free energy F, Gibb's free energy G, etc depending on the conditions imposed. N is just some normalization constant. A(x) can be...

Homework Statement I am supposed to see if there is a feasibility of producing power in the 0.1-0.25 kW range. I am working with a thermosyphon Rankine power plant. It is an open ended design problem My question is that I am getting hung up on finding the mass flow rate. My professor...

This has probably been posted/asked here before as it seems quite basic, but I can't seem to find a thread on it using the search function. According to conventional cap theory (0.5cv^2), two identical caps in series can store twice as much energy as two in parallel (provided the caps in...

Can Anyone Show Me the Steps to solving for these equalities; the proofs for them as it were: Prove that, (dT/dP)s=TV((alpha)p/Cp) and, Cp/Cv=Kt/Ks=gamma and, Cp(Kt-Ks)= TV((alpha)p)^2 (alpha)p = coefficiant of thermal expansion, Kt= isothermal compressibility, Ks=...

Consider the following cyclic process: Each cycle 800J of Energy is transferred from a reservoir at 800K and 600J of energy from a reservoir at 600K. 400J of heat is rejected to a reservoir at 400K and 1000J of work is done. I think that the process doesn't violate the first or second laws...

Hi, Anyone know where I can find thermodynamic properties of gases at high pressure? More specifically I need to find the kinematic viscosity or the absolute viscosity of air at around 300 degrees Kelvin and 330 bar. Cheers

Homework Statement Derive the following: \left(\frac{\partial U}{\partial V}\right)_{T}=T\left(\frac{\partial p}{\partial T}\right)_{V}-p Homework Equations Use the partner equation: \left(\frac{\partial H}{\partial p}\right)_{T}=-T\left(\frac{\partial V}{\partial T}\right)_{p}+V...

1. Five moles of an ideal monatomic gas with an initial temperature of 124*C expand and, in the process, absorb an amount of heat equal to 1140J and do an amount of work equal to 2200J . What's the final temperature 2. Q=m1.5R delta T 3. I tried adding 1440 to 2200 as Q and...

Latent heat of vaporization "Water" thermodynamic -first of all I want to know if the "latent heat of vaporiasation " of water is related to the initial pressure of water ? -If LHV of water is variable with the variation of pressure , how can we calculate the heat needed to vaporise a...

Homework Statement Im given a table with values for Delta(Internal energy), Delta(KE), Delta(PE), Delta(E), Q, and W. For certain ones, certain values are missing and I have to fill in the blanks. Specifically- D()= Delta Process 1-2) D(U) =72, D(KE)= =5 , D(PE)= -6, D(E) = ? ...

Can you check over my answers to see if my reasoning is correct? Homework Statement #3) "Yesterday I woke up and it was 20°F in my bedroom," said Mert to his old friend Mort. "That's nothing," replied Mort. "My room was -5.0°C." Who had the colder room, Mert or Mort? Homework Equations...

Hello, I was wondering if there has been any theoretical work regarding the thermodynamic justification of the Exclusion Principle. It is my view that all open systems proceed to the lowest free-energy state and all closed systems go to the highest entropy state. Of course, these states must...

Homework Statement The problem is on the attachment. I can't seem to find the volume or temperature of T. If someone can tell me how to find them i can do the rest of the problem. Any help would be greatly appreciated. Homework Equations The Attempt at a Solution on the attachment

Homework Statement Show that the average number of photons per unit volume in the cavity for a temperature T is given by n=( I / Pi^2 . (kT/c(h-bar))^3 ) where I = integral from infinity to 0. dx x^2 ((exp (x)-1))^-1 = 2.404 Homework Equations You may assume the mean number...

I'm reading Enrico Fermi's "Thermodynamics" book. In page 3 of his book, he says: It is evident from what we have said that the knowledge of the thermodynamical state alone is by no means sufficient for the determination of the dynamical state. What does he mean by dynamical state...

Homework Statement A gas in a piston-cylinder assembly undergoes a thermodynamic cycle consisting of three processes. Process 1-2: adiabatic compression with pV1.4 = constant from p*1 = 50 psia and V1 = 3 ft3 to V2 = 1 ft3. Process 2-3: isometric, Process 3-1: isobaric with U*1 - U*3 =...

Could a 10 HP diesel engine be made as fuel efficient as say a 100 HP diesel engine, that is (work done/fuel used). Does thermodynamics prevent a smaller engine from being more efficient? Thank you for your time.

Can anyone recommend supplementary texts books for Electromagnetism and Thermodynamics? I'm looking for some alternatives to my recommended textbooks. The first class is an electromagnetics class. This class is heavily calculus based and consists of building up concepts that culminate to...

Homework Statement A restaurant refrigerator has a coefficient of performance of 4.5. If the temperature in the kitchen outside the refrigerator is 28^\circ C, what is the lowest temperature that could be obtained inside the refrigerator if it were ideal?Homework Equations According to...

Homework Statement Here is the question: http://img93.imageshack.us/img93/9159/snap1k.jpg Homework Equations First law: Q=W+U Second law: no thermodynamic system can convert heat into work 100%; heat flows from hot to cold reservoirs spontaneously; entropy always increases The...

http://img527.imageshack.us/img527/1541/physix.jpg Can someone help me with this problem? I'm thinking you have to do some sort of integration but I am unsure.

I am wondering if anyone can confirm this answer I got for the following problem; A coal burning electrical power plant burns at 706 degrees celsius. Heat is exhausted into the river near the power plant; the average river temperature is 19 degrees celsius. What is the minimum possible rate...

I'm having a little trouble in completing this problem. I would appreciate your answer if anyone knows how to solve it. Thanks An ideal refrigerator removes heat at a rate of 0.15kW from an interior temperature of 1 degree celsius. The exhaust from the refrigerator is 45 degrees celsius. How...

Hi, How can I find the thermodynamic work from dw=Pdv if P, Vand T are not constants? what if I knew that dp/dv is a constant in this case?

This is a long problem. Apologies and thanks in advance. 1. Given: In the GTHTR300 plant, a fraction b of the coolant mass flow rate is bled off at the exit of the compressor to cool the turbine disks, shaft bearings and the electrical generator. Due to temperature limitations of the...

Anyone have the learning source for Thermodynamic ? Can share it here? Thx =)

Homework Statement Use the definitions of Helmholtz free energy, F, and Gibbs free energy, H, together with the thermodynamic identity, to show that S = -(\frac{\partial F}{\partial T})_V and S = -(\frac{\partial F}{\partial T})_P Then use those definitions again, and the...