Isothermal Definition and 216 Threads

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)?

Hi, I'm doing a high school physics project and am trying to figure out if a certain setup that I'm using is adiabatic or isothermal, in order to determine what equation I can use to calculate the work that my setup does-- the threads I've come across so far only explain the difference, but not...

Is anyone familiar with these terms or the experiments involved? I have a lot of questions regarding them. Thank you guys.

Hi, I'm trying to make sense of a wave propagation problem. It's a 1D problem, modelling propagation of density perturbations which travel like waves in a fluid. The problem is governed by the mass and momentum equations and density is related to pressure using the bulk modulus of the fluid...

I am really stuck at this question. I tried to get the equation of volume with independent variables P and T, but the equation itself does not give a nice form, and thus I cannot get the derivative of V with respect to P. What should I do?

> The isothermal compressibility $\kappa_t$ of a substance is defined as $$ \kappa_t = -\frac{1}{V} \left ( \frac{\partial V}{\partial P} \right )_T $$ Obtain an expression for the isothermal compressibility of an ideal gas. (PV = RT) in terms of p. I believe that the ideal gas law equation...

Homework Statement One m3 of an ideal gas expands in an isothermal process from 760 to 350 kPa. Determine the specific work done by the gas. Homework Equations ω=W/m 1W2=mRTln(P1/P2) = P1V1ln(P1/P2) P1V1=P2V2 The Attempt at a Solution P1V1ln(P1/P2) = (760)(1)ln(760/350) = 589.29kJ...

The Problem: A 1.80 mol sample of an ideal gas is compressed isothermally from 58.1 L to 15.6 L using a constant external pressure of 2.72 atm . Calculate W: Calculate Q: Calculate ΔU: Attempt at solution: I tried W = P(ΔV) to no effect, W = nRTln[Vf/Vi] to no effect. The online...

I'm sorry for bad english. I wonder what is the differences between reversible-isothermal-expansion and irreversible-isothermal-expansion. Is their entropy same?

Homework Statement Consider an ideal monatomic gas that undergoes an adiabatic free expansion starting from equilibrium state A with volume 500 cm3, pressure 40 kPa and temperature 300K to state B, which has a final equilibrium volume of 1000 cm3. Construct an reversible isothermal path that...

Homework Statement Isothermal process![/B] I have a cylinder with base area of 0.01m^2. I have a piston that is 0.1 meters from the bottom giving a volume of 0.001m^3. I have a weight of 1500 Newtons. This gives a pressure of 1.5E5 Pa. Now, I remove 500 Newtons and the piston moves upwards...

Homework Statement Homework Equations height of liquid above water level ##h=\frac{2T}{R\rho g}## for isothermal process :##PV##=constant And if ##P_0## is atm. pressure, and P is pressure just below the water level in capillary tube, then $$P=P_0-\frac{2T}{R}$$ The Attempt at a Solution...

What does it mean by maximum work of an isothermal, reversible expansion of a perfect gas from initial volume Vi to final volume Vf at temperature T? I understand that heat enters the system during this expansion to ensure that no internal energy is lost but it doesn't really help in anyway...

Hello PF! I have a simple question on energy balances. Suppose you have an isothermal reactor where you want to have an exothermic reaction happening at 450 °C. The simplified energy balance for the reactor is Q = ΔH. Supposing ΔH = -150 kcal, then Q = -150 kcal. Does this mean that, a) in order...

Homework Statement 1 kg of water is at room temperature and the pressure is isothermally increased on the system from 1 atmosphere to 1000 atmospheres. What is the work done? What is the change in heat? What would be the temperature change if this was done adiabatically? The volumetric...

Problem statement, work done, and relevant equations: One mole of ideal gas is initially at 1 atm and has a volume of 5L. a) Calculate the work done on the gas during an isothermal, reversible compression to a volume of 2L. ##W_isothermal = - \int_{v_i}^{v_f} p dv = - \int_{v_I}^{v_f}...

In principle, what happens when an ideal gas undergoes an isothermal process? How is the gas at a constant temperature; is it maintained at that temperature? If we supply heat to the standard ideal piston assembly, why, or rather how is the heat supplied completely converted to work done by the...

I was able to derive the work done in a reversible isothermal expansion. There as the P changes to P-dP, the volume increases by dV and hence the internal pressure also decreases by dP and equilibrium is maintained. (Thanks to @Nugatory and @Chestermiller fo r explaining it). Now when we take an...

why are isothermal process values higher than adiabatic process ones? I know that the volume is powered by gama in adiabatic process ones, and this has an effect. but how can I explain it ?! http://www.popsolving.com/Thermodynamics/Problem2.4_Freebody.jpg

Homework Statement Homework Equations No idea... The Attempt at a Solution Does anyone know how to do question 6b)? Its a past paper question for an exam in 2 days and i have literally no idea where to start.

Homework Statement A quantity of ideal gas (0.800mole) at a pressure of 10.0atm and 200K is allowed to expand isothermally until it reaches a pressure of 1.00atm. Calculate the work done if this expansion is carried out a) against a vacuum, b) against a constant external pressure of 1.0atm and...

Homework Statement A spherical air bubble in a lake expands as it rises slowly to the surface. At the point it starts to rise, the pressure is 2.00 atm, the temperature of the water is 10.0 ∘C, and the radius of the bubble is 5.00 × 10^−3 m. At the surface, the pressure is 1.00 atm and the...

Homework Statement A 0.300-kg sample of nitrogen gas (diatomic molecules,mN2 = 4.652 × 10^−26 kg) in a chamber fitted with a piston undergoes an isothermal expansion from 0.0500 m^3 to 0.150 m^3 . If the final pressure is 110 kPa, what is the final temperature? Homework Equations PV=N*kB*T...

Homework Statement Find ΔH for the isothermal expansion of one mole of CO2 from a pressure of 1 atm to zero at 300 K. The critical point of CO2 is TC = 31 °C and PC = 73 atm. Use the equation for ΔH you previously derived from the Berthelot equation of state. (Answer provided by textbook: ΔH =...

I made a thread on this asking the general question in the other forum, but I don't know how to delete that thread. Homework Statement An isothermal expansion from Vi = 10.0 L, Pi = 2.46 atm against a constant external pressure until the Pf = 0.246 atm. How much work is done by the gas in...

Air: V1= 0,1 m3 P1= 1 MPa T1= 20 C After isothermal expansion P2= 0,1 MPa I had to find T2, M, V2, L, Q and found all those (T2=20 C; M=1,1927 kg; V2=1 m3; L=Q=230258 J) but need s (enthropy) for creating illustration in T-s I can`t find how it`s possible to calculate s1 and s2, is it possible...

Homework Statement [/B] One mole of 2-D ideal gas is confined in an isotropic cone potential: U = \lambda |r| where \lambda is a positive parameter and r is the displacement vector (2-dimensional) from the origin. The...

Homework Statement I am to show that ΔS=Q/T for the isothermal expansion of a monoatomic ideal gas, when the expansion is so slow that the gas is always in equilibrium. Homework Equations 1. law: ΔU=Q+W (We mustn't use dQ and dW - our teacher hates that :( ). Ideal gas law: PV=NkT We need the...

Homework Statement http://puu.sh/c09sc/b1d02302bd.png Homework Equations Conceptual question. The Attempt at a Solution The answer is isothermal expansion(D). but heat does not decrease due to isothermal process and expansion leads to lesser collision of particles on walls of container. So...

Homework Statement Gas obeys Equation of State, PV=RT/(1-bP), where b is a temperature dependent constant. Isothermal process (T is constant) V goes from V1 to V2 P goes from P1 to P2 Show that the amount of Work is W=(P1V1-P2V2)+RTln[(P22V2)/(P12V1) Homework Equations W=-∫P(V)dV...

Homework Statement Consider a solid of compressibility ##\kappa##. Assume that the atoms in this solid are arranged on a regular cubic lattice, the distance between their nearest neighbors being ##a##. Assume further that a restoring force ##-k_0 \Delta a## acts on a given atom when it is...

Homework Statement An ideal gas with Cv = (5/2)R, and Υ = 1.40 undergoes an adiabatic expansion until it has a pressure of 1.0*10^5 Pa and a volume of 2.0m^3. It then undergoes an isothermal contraction of T=300K until it has a volume of 1.0m^3, and then undergoes an isochoric (constant...

My book says that "in the mean field approximation, the isothermal magnetic susceptibility just below the Curie temperature goes as ##(T_c-T)^{-1}##". I need some help understanding how to get this proportionality. My book does not contain any derivation or further explanations. According to...

When an ideal gas expands in a piston during an isothermal process, does it necessarily absorbs heat from the surroundings in order to maintain its temperature? (Piston is not insulated). IF yes, When the same procedure is carried out in a perfectly insulated piston, then temperature drops...

I'll start with what I know: when work is done on an ideal gas its internal energy increases and some of the work is used to increase the volume of the container if the walls are movable, and I know that when a gas does work its internal energy decreases by a value equivalent to F.d, I have...

Homework Statement Homework Equations The Attempt at a Solution I can do everything else except work for part one going from A to B. What I did was -∫PdV = -nRT ∫(1/v)dV = -nRT ln (Vf/Vi) I can solve for T because everything is given, T in Kelvin is 882. From PV=nRT T=(5atm)(10L)/1mol*R...

What equations are relevant to finding the initial and final enthalpy values of an isothermal process? There is an initial dryness fraction and a heat value is also added. I know how to use steam tables to find the initial value of H but not the final. Does H even change? Thanks

Homework Statement 500 Cal are added to a gas inside a cylinder with a piston (containing one mole) by an external heating device. The volume of the gas doubles without any change in it's temperature of 300K. How much work is done on the piston? Homework Equations The Attempt at a...

In my textbook (Physics Principles With Applications - Giancoli 7th Edition) it states that "We assume the gas is in contact with a heat reservoir (a body whose mass is so large that, ideally, its temperature does not change significantly when heat is exchanged with our system). We also...

Ok so I found something online but I need to understand this problem Prove that the ratio of the adiabatic compressibilty ks to the isothermal compressibility kr is equal to the ratio of the specific heat at constant colume, Cv, to that at constant pressure, Cp Definitions of the...

how can we understand total molar concentration remains constant in a isobaric isothermal system? if it is from perfect gas equation pv=nrt although p and t are constant but v isn't constant so since mol number can be change over volume, total molar concentration may change.it is a situation of...

Hello, I am just wondering if it is possible to actually do the following question based on the information given Homework Statement An isothermal reversible expansion, for which pV=constant as shown by the curve joining State A and State B, takes a system from State A to State B along...

The book that I use (Concepts in Thermal Physics by S. and K. Blundell) states the second law in two ways. The way they state the Kelvin version is "no process is possible whose sole result is the complete conversion of heat into work." How does that fit in with the isothermal expansion of an...

Can someone explain to me why Cpln(T2/T1) = 0? Thank you.

I've looked at multiple textbooks that all say this process is ISOTHERMAL (see attached image). I can see why it is indeed ISOTHERMAL, but couldn't also be termed ISOBARIC?

Homework Statement An Ideal gas in a balloon is kept in thermal equilibrium with it's constant-temperature surroundings. How much work is done by the gas if the outside pressure is slowly reduced, allowing the balloon to expand to 6.0 times it's original size? The balloon initially has...

Hallo, I read about thr Carnot-Cycle and got a problem. A->B: isothermal B->C: adiabatic C->D: isothermal D->A: adiabatic I want to understand how to calculate the work done in the isothermal processes. I have read: W_{AB}= T_{H}Nk\ln{(\frac{V_{A}}{V_{\text{B}}})}\\...

Homework Statement A 200g cylinder of metallic copper is compressed isothermally and quasi-statically at 290K in a high-pressure cell. A) Find the change in internal energy of the copper when the pressure is increased from 0 to 12kbar. B) How much heat is exchanged with the surrounding fluid...

Hello all, I've been wondering how water reacts in a closed, rigid system with one moving boundary. Assuming the system is perfectly filled with water, and one side of the boundary moves (increasing the volume), how does this affect the pressure in the system? Since water is...

Homework Statement This is Problem 12.5 in Blundell's Thermal Physics book. Two Thermally insulated cylinders, A and B, of equal volume, both equipped with pistons, are connected by a valve. Initially A has its piston fully withdrawn and contains a perfect monatomic gas at temperature T...