In thermodynamics, an isothermal process is a type of thermodynamic process in which the temperature of the system remains constant: ΔT = 0. This typically occurs when a system is in contact with an outside thermal reservoir, and the change in the system will occur slowly enough to allow the system to continue to adjust to the temperature of the reservoir through heat exchange (see quasi-equilibrium). In contrast, an adiabatic process is where a system exchanges no heat with its surroundings (Q = 0).
Simply, we can say that in isothermal process
T
=
constant
{\displaystyle T={\text{constant}}}
Δ
T
=
0
{\displaystyle \Delta T=0}
d
T
=
0
{\displaystyle dT=0}
For ideal gases only, internal energy
Δ
U
=
0
{\displaystyle \Delta U=0}
while in adiabatic processes:
∫Homework Statement
Compress a body reversibly and isothermally from P1 to P2. How much heat goes in or out?Homework Equations
Maxwells four relations, differential forms of the four thermodynamic potentials (Central, Enthalpy, Gibbs, Helmholtz)
The Attempt at a Solution
My problem is that...
A frictionless piston-cylinder compresses 1 mol of nitrogen to a tenth of its original volume isothermally at 300 K. Assume nitrogen is an ideal gas with Cp*=(7/2)R.
(a) Show two different approaches to calculate the compression work required.
(b) What is the corresponding heat flow?
(c) If...
Homework Statement
Derive an expression for the amount of work done when one mole of an ideal gas expands isothermally at a temperature T from an initial volume V1 to a final volume V2.
Homework Equations
PV = nRT
W = V2∫V1Pdv
The Attempt at a Solution
I'm not really sure how to go...
Homework Statement
A system containing 10kg of water undergoes a reversible isothermal process. The initial state can be characterized as saturated vapor at 300°C. The pressure in the final state is 1MPa. The heat transfer during the process in (inKJ)
Homework Equations
Q = m(U2-U1)+W...
β is expansibility , (1/V)(∂V/∂T) at constant temperature
κ is isothermal compressibility , (-1/V)(∂V/∂P) at constant pressure
How to prove (∂P/∂T) at constant V = (β/κ)
Thank you
Homework Statement
Two identical samples of ideal gas are initially at P1 and V1. The first sample undergoes an isothermal transformation to P2, V2 and second sample undergoes an adiabatic transformation to P3, V2. If P3<P2, is V2 higher or lower than V1? Explain
Homework Equations...
Can we define specific heat capacity for an adiabatic process ??
Would it always be zero since dQ is 0 for an adiabatic process?
Also, can we define specific heat capacity for isothermal processes ?
Would it be infinity in all cases?
Just want to verify if I am thinking along the...
Here's the textbook way of calculating the work done by an ideal gas in an isothermal case.
PV=nRT
P.dV=(nRT/V).dV
∴ ∫P.dV=nRT∫dV/V
→ W2-W1=nRT*ln(V2/V1)
My question.
Consider a cylindrical (or of any other shape) container of surface area A and a frictionless movable piston attached...
Hey all,
I was wondering if someone could explain the difference between isothermal and adiabatic processes. I know that in isothermal process, there is no temperature change in the system, and in adiabatic process, there is no heat transfer. However, can someone explain to me what each one is...
Homework Statement
For an ideal gas, undergoing a quasistatic process, the equations below are correct. Evaluate them given that we have an isothermal process
Homework Equations
PV^\alpha=K where K is a constant and \alpha=C-C_P/C-C_V
W = \frac{K}{\alpha -1}...
Homework Statement
I have a general concept inquiry. I was doing some thermal homework, and calculating values of Q in a given cycle. One process was isothermal, however it turned out that Q was not zero, causing me to wonder: How can there be a heat transfer in an isothermal process...
Heat is defined as "the transfer of energy owing to a temperature difference between two bodies".
Consider a gas expanding against a massless frictionless piston. Assume that the process is both isothermal and reversible, and that the gas is ideal, so that its internal energy does not change...
We were shown in class how to get those entropys.
For reversible isothermal - ΔT=0 thus ΔE=0 thus Q = -W.
ΔS(sys) = Qrev/T = nR(V1/V2)
And ΔS(surr) = -nR(V1/V2) because surroundings made opposite work.
For irreversible isothermal in vacuum - ΔT=0 thus ΔE=0.
No work is done by...
http://www.pichem.net/images//reversible-adiabatic//adiabatic-expansion-2.jpg
Evidently the adiabatic curve is steeper than the isothermal curve.
How can I prove this mathematically using the following facts:
P_{1}V_{1} = P_{2}V_{2} for a reversible isothermal process...
Homework Statement
I have hydrogen in a 12 L tank, at T=15 C. Some of it is used, the T = const. and Δp=0.4 MPa,
the molar mass of hydrogen is M=2*10^-3 J/(mol*K). Find the mass of the used hydrogen.
Homework Equations
Am I wrong in simply using:
\Delta m=\frac{M}{RT}V\Delta p ...
Homework Statement
Variables: N (number of particles), μ (chemical potential), P (pression), V (volume).
k is Boltzmann's constant. I often use β=1/kT.
The (isothermal) compressibility is given by
\kappa_{T} = -\frac{1}{V}\left (\frac{\partial V}{\partial P}\right )_{N,T}
The...
Homework Statement
In the graph attached, why is isothermal graph line higher than adiabatic one??
Homework Equations
The Attempt at a Solution
At first, i had thought that work done in an isothermal process is greater than in an adiabatic process...but for comparison we would...
Homework Statement
In calculus, the work done when a gas expands from volume V1 to volume V2 is given by
W = ∫V2V1 P dV
Use this expression to show that the work done by n moles of gas at temperature T during an isothermal expansion from volume V1 to V2 is
W = nRT ln(V2/V1)
Homework...
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...
Homework Statement
A projectile of mass M kg is accelerated from rest to V m/s using a compressed air cannon. conceptually, we may consider the projectile to be a frictionless "piston" within a cylinder that is closed at one end and open to the atmosphere at the other end.
Before firing...
Homework Statement
A 740g quantity of an ideal gas undergoes a reversible isothermal compression at a temperature of 330 K. The compression reduces the volume of the gas from 0.40 m3 initially, to 0.32 m3 finally. The entropy change of the gas is equal to:
A) -43 J/K B) -150 J/K...
Homework Statement
Homework Equations
Work done by an ideal gas, isothermal process: W=n*R*T*ln(V_f / V_i)
Work, constant-pressure process: W=p*(V_f - V_i)
The Attempt at a Solution
I first tried plugging n=1, R=8.31, T=273.15, V_f=17.5 L, V_i=24 L into the first equation and it...
Homework Statement
Using any software, create the enthalpy table for the following two cases of superheated steam:
1. Isobaric process at a chosen pressure in 100 spaces of 5 degrees celcius.
2. Isothermal process at a chosen temperature, given Vg from the book, in 1000 spaces of 0.1 bar...
Homework Statement
I have to simulate an isothermal filling of a cavity using Autodesk Mouldflow Insight.
Homework Equations
The Attempt at a Solution
I tried setting the mould temperature to the melt temperature but I do not seem to get a reasonable answer as the cavity will fill...
Homework Statement
A thermally isolated chamber is pumped down to a very low pressure. At some point, the chamber is vented slowly so that it is filled with air up to atmospheric pressure, whereupon the valve is closed. The temperature of the air surrounding the chamber is T0=300 K. What is...
i'm entirely confused with this.
with analyzing each definition:
adiabatic process : a thermodynamic process in which there is no transfer of heat
if a system is in state (P1, V1, T1) → (P2, V2, T2) if it is adiabatic no heat transfer occurs, if no heat transfer occurs the two states must be...
Homework Statement
A compressor is required to drive acetylene gas at 1.85 kg/s through a horizontal pipe, 68.7 m long. The maximum pressure that may be developed by the compressor is to be found, and gas pressure at the delivery end of the pipeline must be 470 kPa. The system is to...
For a process at constant pressure, ΔH=q.
My textbook clearly says that the only way that enthalpy can change is with a change in temperature. So ΔH=0. But q≠0 for an isothermal process.
I know that ΔU=0 for an isothermal process. So ΔH=0+Δ(PV)=Δ(nRT)=0
It really seems like ΔH should...
Homework Statement
Is work greater in adiabatic or isothermal process?
A piston with oxygen has a final volume 1/4 the initial. The temperature is also 5 times greater. Determine pressure change, heat released or absorbed, and work done on or by gas.
Homework Equations
the work for adiabatic...
Homework Statement
In a reversible isothermal expansion of an ideal gas, as the gas expands, heat is supplied to it, so that the temperature remains constant. Thus, temperature and hence kinetic energy of the molecules does not change but the 'disorder' of the gas increases as it occupies a...
I have these two homework problems, as well as solutions. What I do not understand is why the solution for one is not the solution for the other.
First problem:
A sample consisting of 1.00 mol Ar is expanded isothermally at 0 deg Celc from 22.4 dm3 to 44.8 dm3 reversibly. Calculate q, w, delta...
using the isothermal transformation diagram provided of an iron-carbon alloy at eutectoid composition, determine the final microconstituants and approximate percentages of a small specimen that has been subjected to the following time-temperature heat treatments. in each case assue the specimen...
Homework Statement
To a very good approximation, ammonia obeys the Bertholet equation of state,
which readsPV=nRT+\frac{9}{128}(\frac{nRTc}{Pc})(1-6\frac{Tc^2}{T^2})Pa)Suppose we have 500 grams of ammonia under a pressure of P=3.04 atm
and at T=323K. Calculate the volume of ammonia according...
If U, H are functions of T only, then ΔU and ΔH should be zero for isothermal processes
ΔG and ΔA are only defined at constant T (thus define isothermal processes)
ΔG = ΔH – TΔS thus equals -TΔS always (since ΔH=0)?
this makes no sense since from previous calculations I have done in many...
i have done an isothermal titration calometry with a DNA intercalating drug and a G4 C4DNA sequence. i planned on doing this at different temperatures to obtain a van't hoff enthalpy for the binding reaction. standard papers compare the enthalpy to experimental calorimetric enthalpies to predict...
1. Homework Statement
Two equal masses of an ideal gas initially at the same temperature and pressure are compressed to half of their initial volumes, one of them isothermally, and the other while thermally isolated from its surroundings.
Which one of the following is the same for both...
Hi,
Adiabatic, iosbaric and isochoric processes are good approximations for a lot of thermodynamic phenomena in every day life.
But the conditions for a process to be isothermal are so artificial that i have grave difficulties to fudge a story.
Are there any examples of thermal...
1 mole of an ideal gas is compressed isothermally from 1 to 10 bar at 298 K. Calculate the total entropy change associated with this process if it is carried out
1) Reversibly
2) Irreversibly
S (system) =nRln(vf/vi) for an isothermal process.
I think I am getting a bit...
Homework Statement
200W of power is required for an isothermal process of a larger cyclic process.
Use the first law of thermodynamics to calculate the amount of heat power that is generated by the isothermal process.
Homework Equations
Change in heat energy = change in internal energy +...
1.>Consider a gas in a vessel with a piston on top.Let it expand to a greater volume.
So,
delta H=delta U+delta(PV)
but delta U is 0 as it is isothermal.
now,as the number of moles of gas remains constant,delta(PV) is nR(delta T) which is again 0.
SO delta H is 0.
Thats what my book says...
Isothermal problem!
Imagine an idead cylinder and piston and gas filled in it with the Pgas=Patm.
Ideal gas Equation for initial state is PV=nRT for the gas....(1)
Now is dQ heat is imparted to the gas. Pressure of the gas at that instant increases by dP so it expands by dV to attain...
I have a question on the quantity -(dV/dP)T,N where V = volume, P = pressure, T = temp, N = number of moles and T, N are held constant. I see in textbooks that this quantity is always positive at equilibrium. It makes intuitive sense, as if it were negative, it would be unphysical. I've been...
On any smooth surface one can choose isothermal coordinates in a neighborhood of any point.
What is the physical interpretation of this fact?
Do the isothermals describe an equilibrium distribution of temperature? How would that be true say on a sphere?
Homework Statement
Air with the mass of 10kg, with pressure 15 bar and temperature 50 C comes to a isobaric expansion to 3 times the original volume, then the air cools to the pressure of 6 bar(isovolumetricly). After that it comes to adiabatic expansion to original temperature (50 C i guess)...
Homework Statement
I have a diagram of a process of a monoatomic gas.
and the problem is that I know that the total amount of work = total amount of heat,
so there is no internal energy change. why? because my process started at the same temp that it finished. how ever... it is asking me...
What are Internally reversible processes and why isothermal processes are reversible?
Also, Isothermal process are only internally reversible or they can be "externally" reversible?
I am reviewing material for my thermodynamics class and one of the practice exams says that the change in enthalpy during an isothermal process is equal to zero. This doesn't make any sense to be considering..
\Delta H = \Delta U + PV
and since this is an isothermal process..
\Delta U =...
Homework Statement
Calculate the increase in internal energy of 1 kg of water at 100 degrees Celsius when it is converted into steam at the same temperature and at 1atm. The density of water and steam are 1000kg/m3 and 0.6kg/m3 resp. The latent heat of vaporisation of water is 2.25 x 106...
Homework Statement
One mole of monatomic ideal gas is taken from an initial pressure(P) and volume(V) to a final pressure(2P) and volume(2V). It goes from pressure=P and volume=V to pressure=P/2 and volume=2V through isothermal expansion and from there volume stays constant but the pressure...
Homework Statement
One mole of an ideal monoatomic gas initially at 300 K is expanded from an initial pressure of 10 atm to a final pressure of 1 atm. The molar heat capacity for constant volume for the gas is C_V = 3/2(R).
Calculate ΔU, ΔH, q, w, and the final temperature (Tf) for an...