Thermodynamics Definition and 1000 Threads

Homework Statement The thermal dissociation equilibrium of CaCO3 (s) is studied under different conditions. CaCO3 ⇔ CaO (s) + CO2 (g) For this equilibrium, the correct statement(s) is (are) (A) ΔH is dependent on T (B) Keq is independent of the initial amount of CaCO3 (C) Keq is dependent on...

Hello! This is an old problem from the Estonian-Finnish open physics olympiad (2013) and I hope you will be able to lend me some help. 1. Homework Statement Sun-rays are focused with a lens of diameter d = 10 cm and focal length f = 7 cm to a black thin plate. Behind the plate is a mirror...

Homework Statement A column of water contains fine metal particles of radius 20 nm, which are in thermal equilibrium at 25°C. If there are 1000 such particles per unit volume at a given height h0 in the water column, how many particles would be found in the same volume 1.0 mm higher than h0...

THIS WAS MOVED FROM ANOTHER FORUM, SO THERE IS NO TEMPLATE. HOWEVER, THE OP DID SHOW SOME EFFORT Hello, I have been having troubles beginning these two problems given for exam prep. Was wondering if anyone could give guidance on where to begin. Problem 1: A cylinder with adiabatically...

Homework Statement Hi ! I'm stuck with these two questions of my assignment of thermodynamics - Give two exemples of irreversible process (initial state, process, final state) - For each of them, explain why they are irreversible on the microscopic scale. Homework Equations We are not asked...

Homework Statement Problem from the book "Engines, Energy and Entropy", Page 55, question 7 has me stumped. It doesn't feel like their is sufficient information to work out the mass of the air. They've given us density (as seen in the picture, if the upload works) , which is mass over volume...

Homework Statement A turbine is receiving air from a combuster inside of an aircraft engine. At the inlet of the turbine I know that T1 = 1273 K and P1 = 549 KPa, and the velocity of the air is essentially 0. The turbine is assumed to be ideal, so its efficiency is exactly 1. Also: R = 287...

Homework Statement An ideal gas enclosed in a vertical cylindrical container supports a freely moving piston of mass M. The piston and cylinder have equal cross sectional area A. When the piston is in equilibrium, the volume of the gas is V0 and its pressure is P0. The piston is slightly...

Homework Statement A sample consisting of 1 mol of a diatomic perfect gas with Cv,m = 3/2 R is heated from 100 ºC to 300 ºC at constant pressure. Calculate ∆S for the system. Homework Equations Cv,m = 3/2 R The Attempt at a Solution Cpm=Cvm +r because we want cp right isobaric ∆S= Cp ln...

ok so I am in this class... but my professor is not very helpful. I'm not really caring for the assigned textbook, I want to try a different one. One of the issues is that my professor just threw the textbook away and is doing his own thing, so it is difficult to try and study from the textbook...

Homework Statement Consider air expansion inside a cylinder. Assume that the volume and initial pressure is 1 ft^3 and 1500 PSI ABS respectively. If the expansion process is reversible and the path is given by P.V^1.4=constant. Calculate the total work done by the gas to reach the final volume...

Homework Statement Show the steps needed to obtain the equation for average molecular speed, cavg=√8RT/πM from the integral (from negative infinity to infinity) ∫v*f(v)dv where f(v) is the Maxwell distribution of speeds function f(v)=4π*(M/2πRT)1.5v2e-Mv2/2RT M is the molar mass of the...

I am aware of the Second Law of Theromodynamics and I understand it to a certain extent, although still I am burdened with the frustration of being ignorant to why such a law exists. Please assist me.

Homework Statement Two rigid, insulated tanks are connected with a pipe and valve. One tank has 0.5 kg air at 200 kPa, 300 K and the other has 0.75 kg air at 100 kPa, 400 K. The valve is opened, and the air comes to a single uniform state without any heat transfer. Find the final temperature...

Hello all. I have a quick question about entropy... I've just been formally introduced to it. Consider the example of a metal block of mass m and heat capacity Cp at temperature T1 = 60C being dropped into a large lake of temperature T2 = 10C. $$\Delta S_{block} =...

Homework Statement When 0.40 mol of oxygen(O2) gas is heated at constant pressure starting at 0 degrees C, how much energy must be added to the gas as heat to triple its volume? (The molecules rotate but do not oscillate) Homework Equations pV=nRT p1V1/T1=p2V2/T2 Q=mcdT Value of Cp for Oxygen...

I want a book on Thermo and statistical physics that will give me a clear insight on every basic thermodynamics systems. I am already done with Shroedar's introduction to thermal physics btw. I basically need a book that clears my concept more than solving problems. And the more on...

I was hoping if anyone has studied it ,I might get help especially regarding its exercise.

Homework Statement Here is the problem: An inventor claims to have developed a heat pump that provides a 180 kW heating effect for a 293 K household while only consuming 70 kW of power and using a heat source at 273 K. Can this claim be possible? Homework Equations COP of heat pump = Qh/W COP...

Homework Statement We have 0.0008 Kmol of an ideal gas are expanded from V1 to V2 v2=3V1 process is reversible and T/V=Constant if the work obtained by this expansion is 9.4 KJ find the initial temperature R=8.314 KJ Kmol-1 Homework Equations PV=nRT possibly T/V = T/V The Attempt at a...

I have a quick question concerning the 2nd law of thermodynamics. So my textbook uses an illustration to explain how the violation of the Clausius statement of the 2nd law implies a violation of the Kelvin-Plank. But while looking over the diagram I stated thinking about a certain situation. In...

Homework Statement T junction 5 kg/s of methane enters on one side at P1 = 1 MPa, T1 = 400 K, and 1kg/s of methane enters on the otheras a saturated liquid at P2 = 1 MPa. The two streams are mixed and emerge at P3 = 1 MPa. Determine the temperature of the discharge stream (T3).Homework...

Homework Statement Homework Equations specific volume = volume / mass dryness fraction = mass of vapor / total mass pressure The Attempt at a Solution part(a) is totally not relevant to part(b) and I finished part (b)i dryness fraction = 0.5244 specific volume = 0.0502 m^3/kg specific...

Can anyone explain to me why does temperature of water remains constant while boiling in an open vessel or in general sense why phase transition is isothermal in nature?please give me answers from thermodynamic point of view also.

What about Thermodynamics by Zemansky? Any review?

If you put everything in a rest frame, it seems as if it's impossible to tell an isolated system from a closed system (globally in SR, locally in GR). Am I off my rocker to think so? There's at least one catch I've thought of so far: light. I can't say for sure that it satisfies either...

Can someone differentiate between differet types of expansion, Joule's expansion (free expansion) Adiabatic expansion Joule - Thomson or Joule - Kelvin expansion

A paper I'm reading says that the 2nd Law of Thermodynamics is related to unitarity. And it references: S. Weinberg, "The Quantum theory of fields. Vol. 1: Foundations" Does anyone here know what this might mean?

Homework Statement A triple glazed window consists of 3 clear glass panes of 3 mm thickness each, separated by air cavities of 12 mm each. The window area is 1.0 m2 . If the thermal conductivity of the glass panes is 0.8 W•m-1•K-1 and of the air cavities is 0.028 W•m-1•K-1 what is the total...

Homework Statement Calculate ∆rH° for the reaction c2h50h+3o2-->2co2+3h20 Given that ∆rU° = - 1373 kJ mol-1 at 298K. Homework Equations c2h50h+3o2-->2co2+3h20 The Attempt at a Solution delta H f CO2(g) = -393.5 kJ/mole delta H f H2O(l) = -241.8 kJ delta H f O2(g) = 0 these values are...

Homework Statement Homework Equations The Attempt at a Solution 1) I think the answer is c) . Since initially there is no pressure above water , it starts vaporizing . This causes loss of thermal energy from water . The heat lost results in water freezing .The process continues till all the...

Why does ∆S = 0 for a reversible process, but for a reversible isothermal process, ∆S is given by nRln(Vf/Vi) (or other variations of that equation)?

A hot object in thermal contact with a cold one will finally reach a temperature in between. Why can the entropy change of each object be calculated as if the process was reversible? Is there a reversible process with the same final and initial state and what would that be?

I have a small confusion that can an irreversible engine have greater efficiency than reversible engine if both have different source and sink temperatures?I know that under same conditions reversible engines are more efficient but what can be concluded under different conditions like both...

Homework Statement A sample consisting of one mole of a diatomic perfect gas is heated from 25 °C to 200 °C at constant volume. Calculate q, w, ΔU and ΔH for the process, given that Cv = 23.02 J K-1 mol-1 . Homework Equations Im studying for mid terms and i have no lecture notes on diatomic...

Homework Statement A gas in equilibrium has distribution function: f(p,r) = C0*(1+y*x)(2*pi*m*k*T)-3/2*exp(-p2/(2*m*k*T)) where x is the distance along an axis with fixed origin, and y is a constant. What's the nature of the force acting on this gas? Homework Equations Maxwell bolztmann...

Homework Statement Hi, A question on work done in inflating a square balloon. Homework Equations Work done = integral of p*dv (see below). The Attempt at a Solution I just wanted some pointers on the following. Work done = integral of p*dv. But I don't know if p0 would be taken into...

Homework Statement Im having a little trouble with knowing what to assume for the dead state! In the question that I posted, I don't understand how they knew to assume that the water in the system is a super heated vapor? Or how they knew that the dead state is a compressed liquid? Homework...

Homework Statement I'm working on a problem that says that >If $\varepsilon_{\pm}=\mp (\mu \mu_0 H + k \theta \frac{M}{\mu N} )$ is the energy of the atom of a specimen that can orient itself either parallel or antiparallel in a magnetic field, show that $ \frac{M}{\mu N}= tanh(\frac{1}{kT}(...

Calculate the difference between heat of reaction at constant pressure and at constant volume for following reaction at 298 K. N2(g)+3H2(g)→2NH3(g) My attempt ~ At constant pressure ΔHp=ΔUp+PΔV At constant volume ΔHv=ΔUv ∴ΔHp-ΔHv =ΔUp-ΔUv+ PΔV And PΔV = ΔnRT But what to do of ΔUp-ΔUv? In...

My thermo teacher was talking about 2 phase rankine cycles and he said the once water boils at atmospheric pressure its temperature can not get higher than 212 no matter how much heat you add. He said the only way you can raise the temperature of steam past 212 F is the raise the pressure. Why...

This is a question on my review package, but I still cannot understand the solution and do not know why my solution is wrong. Homework Statement The PV diagram is attached. Problem: During change AB, 300 J of thermal energy is supplied to the gas. During change BC, 250 J of thermal energy is...

If for two reversible processes we have the same internal energy change, if work done is maximum for one, is heat transfer minimum and vice versa? The logic that I use is that since dU=dQ+dW, for constant dU if dW is more for one, heat transfer dQ is less and vice versa just to keep the sum...

Homework Statement A cylindrical container with rigid walls is divided in two sections by a barrier with negligible mass that is free to move without friction along the axis of the cylinder. The barrier is adiabatic and so is half of the cylinder while the other half let's heat through. The...

Homework Statement The coefficient of linear expansion of a rod of length 1 meter (at 300K) varies with temperature as ##\alpha=\frac{1}{T}##, where T is the temperature. Find the increment in length when the rod is heated from 300K to 600K Homework Equations $$\Delta L=L\alpha \Delta T$$ The...

Homework Statement Ideal Rankine cycle includes irreversibilities in the adiabatic expansion and compression processes. Find the isentropic efficiency of the turbine. ***My book uses a subscript 2s to denote the ideal state State 1: p1=60 bar h1=2784.3 kJ/kg x1=1 s1=5.8892 kJ/kg*K...

Using an ablative carbon-carbon heat-shield, what thickness would be used up? Or might a ceramic insulator be able to handle it? What would happen if the nose was solid aluminium?How can this be calculated? What information do I need to figure this out?

So I understand that thermodynamics of a chemical reaction is the change in Gibbs free energy and that kinetics mainly deal with the activation energy (or production of a high energy intermediate). My question comes from something that my organic chemistry professor stated in class. He said...

Homework Statement Since the 1980's a total of 20 x 10^22 J of additional energy has been absorbed by the worlds oceans. This is 90% of the additional heat our planet is storing as a consequence of global warming. The surface area of the worlds oceans is 361,900,000 km^2 and we will assume this...

Homework Statement The first excited state of the helium atom lies at an energy 19.82 eV above the ground state. If this excited state is three-fold degenerate while the ground state is non-degenerate, find the relative populations of the first excited and the ground states for helium gas in...