Isobaric Definition and 81 Threads

Using the adiabatic process formula, I've calculated the change in volume for a volume of gas with an initial pressure of 10 psig expanding to 0 psig. The initial volume is 100 cubic inches and the expanded volume is 144.9. This is a difference of 44.9. The total work done ends up being about...

1. Adiabatic compression (When compressed quickly, there is no heat flow to the environment Q=0) Isochoric with heat loss (The syringe is still compressed, there should be no change in volume) Adiabatic expansion (When the syringe is released, there is work done only) Isochoric with heat gain...

(i) In this case the gas is expanding therefore its volume will increase and the pressure will drop. As volume gets bigger particles have more space to move around. Isobaric is curve (1-2). It’s a horizontal line because here the pressure is constant. Isothermal is curve (1-3) temp is constant...

Homework Statement: A PV diagram shows an isobaric expansion, I'm asked to know the signs of: work done on, heat added to, and change in energy content of the system. Homework Equations: W= integral (P dV), dU = Q + W Since this is an expansion, the system does work on the surrounding and...

In case of isobaric expansion, the system expands at constant pressure(the external pressure i.e. the resistance is constant.).In case of flow work, the fluid trying to exit the control volume, pushes against the pressure at the exit of the control volume or when entering the control volume, the...

Homework Statement Consider a 1000 to 700 hPa layer in the atmosphere that is at rest and is in hydrostatic balance. The layer is subjected to radiative cooling at a rate of 5.0e3 J/s/m2 for one hour. a) Calculate the change in mean temperature for the layer assuming all energy goes into...

Consider the following problem: Gaseous helium (assumed ideal) filled in a horizontal cylindrical vessel is separated from its surroundings by a massless piston. Both piston and cylinder are thermally insulating. The ambient pressure is suddenly tripled without changing the ambient temperature...

Homework Statement An ideal gas with Cv = 5/2R, and γ = 1.4 starts at a volume of 1.5m3 , a pressure of 2.0×105Pa, and a temperature of 300K. It undergoes an isobaric expansion until the volume is V , then undergoes an adiabatic expansion until the volume is 6.0m3 , and finally undergoes an...

I have been researching the Rankine cycle. I know that it consists of two adiabatic and two isobaric processes. However, I'm not entirely sure why we ignore the work done during the isobaric processes (this seems to be the case in the analysis I'm looking at). Is that because the work done there...

Homework Statement [/B] This is a very basic question. I have a cylinder filled with air having stops at a particular height . First part of the process is isobaric as piston is free to move and P is constant. When piston reaches stops this becomes isochoric process as volume is constant. So...

We have a piston with ideal gas in it and a weight. The weight is placed on the piston. The gas is heated externally and the gas expands. Will the expansion be isobaric or isothermal? One argument would be: the expansion will be isobaric because the weight is providing constant pressure. The...

In a isobaric process W=PΔV I Given the change in temperature and pressure is constant to find heat added to an mono-atomic ideal gas we use Q=ΔU + W = 3/2 nRΔT + PΔV = 3/2 nRΔT + nRΔT so Q=5/2 nRΔT correct? II But given the heat added to an ideal gas, constant pressure that acts on the...

Homework Statement A cylinder contains 0.250mol of carbon dioxide (CO2) gas at a temperature of 27.0∘C. The cylinder is provided with a frictionless piston, which maintains a constant pressure of 1.00atm on the gas. The gas is heated until its temperature increases to 127.0∘C. Assume that the...

Homework Statement Consider a cylindrical tank closed by a movable piston with mass ##m=3 kg##. The radius of the cyclinder is ##r=7.5 cm##. In the tank there is a mass ##m'=2 kg## o water at temperature just below ##100°C##. At the base of the cyclindrical tank there is an electrical heater...

In a adiabatic process (not necessarily reversible) from ##V_a## to ##V_b## the work can be written as $$W=\frac{p_aV_a-p_bV_b}{\gamma-1}$$ Where ##\gamma= \frac{c_p}{c_v}## Suppose that the adiabatic process in question (again, not necessarily reversible, so ##pV^{\gamma}## can also not be...

Homework Statement This is probably a real easy task for most, but I simply CANNOT manage to calculate it, even given the correct answer. I will translate it as best I can and hope I don't phrase it in a way that causes misunderstandings: 12 Moles of an ideal gas go through an Isobaric...

Homework Statement A gas is to be expanded from initial stage i to final stage f along either path 1 or path 2 on a p-V diagram. Path 1 consists of three steps: an isothermal expansion(work is 23J in magnitude), an adiabatic expansion(work is 35J in magnitude), and another isothermal expansion...

I understand if isobaric work is done on a system then its internal energy must increase, meaning that the temperature must increase as well. However, according to Charle's Law, volume is proportional to temperature which means that if volume decreases, so must temperature. How can the two...

1. Homework Statement When volume changes from V to 2V at constant pressure then the change in internal enrgy will be? 2. Homework Equations ΔU= nCvΔT 3. The Attempt at a Solution I have used the equation ΔU= nCvΔT but the answer is PV/γ-1

Homework Statement [/B] You are asked to calculate changes in internal energy, entropy, heat transferred and work done for each of the following process. Also you are asked to calculate "the latent heat for the isotherm in the figure". We know the a and b parameters which characterize the VdW...

We have an ideal gas enclosed in cylinder whose top is covered by a piston of certain weight ##mg##. At this stage, the piston is at rest which means the force by which the gas acts on the piston (##F=PA## where ## P## is the gas pressure and ##A## is the cross sectional area of the cylinder) is...

Homework Statement Find a one-parameter family of solutions to the isobaric equation (x+y)dx - (x-y)dy = 0 The Attempt at a Solution First I subtracted -(x-y) to the both sides Step 1: (x+y)dx = (x-y dy I then distributed dx into (x+y) and dy into (x-y) to get Step 2: xdx +ydx = xdy -ydy I...

Homework Statement Hi, I'm a new user and got this problem. Sorry to bother, but I couldn't find any relevant information from my Physics books.. The problem states: Build a heat engine using these processes: adiabatic, isothermal, isochoric and isothermal. The work-cycle of the engine must...

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...

If I heat a rubber balloon filled with helium slowly and if the balloon is fully expandable and (the balloon) can be assumed to require no energy in its expansion,what type of thermodynamic process is taking place? Is it isobaric? Since the balloon expands the pressure exerted by the gas on...

Hello PF! I have some questions regarding these concepts. First of all, are the following expressions valid for any case? i.e. any kind of process, like isochoric, isobaric. \Delta U = \int C_v \ dT \Delta H = \int C_p \ dT Or is the ΔU expression only valid when dV = 0, and ΔH when dP = 0...

Homework Statement Consider an ideal gas with C_V=6.76 \frac{cal}{mol \cdot K}. Calculate \Delta H and \Delta U when ten moles of this gas are heated from 273.15 K to 373.15 K. Homework Equations \Delta H = \Delta U + P\Delta V Q=n C_V \Delta T The Attempt at a Solution As I'm given the heat...

It is said that in an isobaric expansion of a gas pressure remains constant throughout the expansion process. Suppose we have a quantity of gas at initial pressure P1 and volume V2 in a piston cylinder arrangement.We heat it slowly such that it expands to obtain a state with pressure P2 and...

Homework Statement A 1kg box of Aluminum initially at 22C is warmed at P=1atm so that its T increases to 40C. Find a) The work done on the system Homework Equations W= -∫PdV The Attempt at a Solution The pressure is constant at 101,300Pa D=m/V So V=m/D D of Al at room...

Homework Statement How much work is done on the gas in the process shown in figure P12.24. This is from College Physics: A strategic approach, 2nd addition, by Knight, et al. Ch.12, #24 The graph shown is kPa vs V(cm^3). It's a constant temperature process (isobaric) at 200 kpa. I was able to...

Just wanted to ask why is it that for isobaric processes, when we wanted to find Q, sometimes we use Q = nCpΔT and sometimes we use Q = nCvΔT + p(Vf - Vi)? How do we determine which should be used and when?

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...

In an isobaric process of 1 mole of a monatomic ideal gas, the pressure stays the same while the volume and temperature change. Let's take an isobaric expansion where the volume increases by 2m3 and the pressure stays at 5kPa. If the work done by the gas is the pressure times the change in...

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 Assume nitrogen gas (N2) is an ideal gas. n = 7.57 moles of N2 gas are heated isobarically (at constant pressure) from temperature To = 18.6 oC to temperature Tf = 50.9 oC. Find: c) ΔIE, the change in internal energy of the N2 gas Homework Equations Change in IE...

Homework Statement n = 1.46 moles of ideal gas are heated isobarically (at constant pressure) from temperature To = 431 oC to temperature Tf = 1227 oC. Find: change in Energy, Q, W. Homework Equations Change in IE = Q + W W (isobaric process) = P(vf-v1) The Attempt at a Solution...

Hey, during last lecture of thermodynamics we did polytropic processes, and with no discuss teacher said, that isobaric process is in general polytropic. If we had ideal gas, then it is clear, bud what if the gas isn't ideal? I tried to proof it, but I stuck and don't know how to continue...

Hi there, I'm having a great deal of trouble with this thermodynamics question. Cylinder filled with steam at 350 kN/m2. Initial volume is 0.05 m3. Sufficient heat transfer is effected to raise the internal energy in each cylinder by 50 kJ. The piston is moved slowly to maintain the...

Hello.I'm studying thermodynamics and I'm having trouble understanding processes where the pressure is constant.How can temperature alone modify the volume without doing pressure.An example would be appreciated.Thanks.

Hi! I have this experiment, that keeps getting me frustrated. The experiment is simple: We have hot water and a long plastic tube with one end closed. We simply measure how much water is in the tube and from that we get the water volume (water is in cylinder shape). But there is something I...

Hello All, I am interpreting a diagram from the following question. (I didnt have a chance to take thermo and I learned it by myself so I might have some problems) http://www.physicsgrad.com/pgre/9677-15 I understand that I can just do ΔW and I get the right answer, but upon doing it...

Homework Statement An ideal monatomic gas has an initial pressure of 3 atm, an initial volume of 1 L, and is at an initial temperature of 90 degrees Celsius. It first expands isothermically to 2 L and is then cooled isobarically to a point where it is adiabatically compressed to its initial...

Homework Statement The figure(Figure 1) shows a thermodynamic process followed by 150 mg of helium. Determine the pressure (in atm) at points 1, 2, and 3. Determine the temperature (in °C) at points 1, 2, and 3. http://imgur.com/B7lwQ n=.0375 mol P1=3 atm P2=1 atm T1=971.85 k T2=971.85 k...

hi ... These days i am trying to make sense of the various processes of thermodynamics and so far i have tried the isothermal process , and isochoric process (which is quite simple i think). Now i am trying to describe what i have understood by the isobaric process: According to the basic...

I know this question has been done to death and I have had a look through past questions on this forum and others but I can't find anything that is helpful to this particular question! Homework Statement An ideal monatomic gas expands reversibly at a fixed pressure of 10^5 Pa from a...

hi all, i have a confusion about the internal energy change and work done in a isobaric system... suppose i want to find the delQ in isobaric system in terms of P & V...now i may assume the delW part would be pdv=p(V2-V1)...as i m compressing the gas... but what happens to the du? and is the...

Suppose the following an isobaric system an ideal heater(1) of infinite area on a single plane in a STP environment the heater is set to a given temperature At a given distance perpendicular to the heater surface, what will the density of the gas be over time? I spent a good part of the...

Foremost, this is my first post on PF, but I have used the sites archives extensively for help on my physics homework this semester, so many thanks to all! You have no idea how much you helped save me time, points, and also improved my understanding of the material. But I'm stuck on a very...

Homework Statement We have an ideal gas of N particles with mass m and temperature T and volume V. a) Calculate \langle E_{kin} \rangle We now reversibly compress the gas from volume V to V/2. During this compression heat Q is added, work W is done on the gas and the energy of the gas...

Homework Statement An ideal gas of N particles is reversibly expanded from V1 to V2 = 4V1. The starting temperature T1 is known and E_1 = \frac{3}{2} N k_B T_1. As of yet E_2 is unknown. a) Express \Delta E = E_1 - E_2 in terms of the added heat Q and work done on the gas W. b) Calculate...