Why is no work done in free expansion?

The gas expands on its own without external pressure acting on it. So according to the equation of work in thermodynamics W=Pext Δ V. Since external pressure is zero, the work done during the free expansion is zero.

What is the difference between isothermal and adiabatic process?

As per the thermodynamic terminology, in the adiabatic process, there is no exchange of heat from the system to its surroundings neither during expansion nor during compression. Whereas in the isothermal process, the temperature remains constant throughout the work.

What is work done in adiabatic process?

When an ideal gas is compressed adiabatically (Q=0), work is done on it and its temperature increases; in an adiabatic expansion, the gas does work and its temperature drops.

Is free expansion isothermal process?

If there is also no work done, i.e. a free expansion, there is no change in internal energy. For an ideal gas, this means that the process is also isothermal. Thus, specifying that a process is isothermal is not sufficient to specify a unique process.

Why isothermal process is very slow?

In isothermal process, temperature of the system is constant and also equal to that of surroundings in contact with the system. Since the temperature difference would be small, the rate of heat transfer would be very slow. So from a practical point of view, the isothermal process is very slow.

How is isothermal work calculated?

A curve in a P-V diagram generated by the equation PV = const is called an isotherm. For an isothermal, reversible process, the work done by the gas is equal to the area under the relevant pressure -volume isotherm. It is given as WA→B=NkTlnVBVA W A → B = NkT ln ⁡ V B V A .

Which work done is more adiabatic or isothermal?

Both start from the same point A, but the isothermal process does more work than the adiabatic because heat transfer into the gas takes place to keep its temperature constant. This keeps the pressure higher all along the isothermal path than along the adiabatic path, producing more work.

What is expansion give an example?

Expansion is defined as the act of getting bigger or something added onto something else. An example of an expansion is an extra three rooms built onto a house.

Is adiabatic expansion reversible?

Adiabatic free expansion of a gas For an ideal gas, the temperature remains constant because the internal energy only depends on temperature in that case. Since at constant temperature, the entropy is proportional to the volume, the entropy increases in this case, therefore this process is irreversible.

What is work and heat?

Heat and work are two different ways of transferring energy from one system to another. Heat is the transfer of thermal energy between systems, while work is the transfer of mechanical energy between two systems.

Is free expansion reversible?

The Joule expansion (also called free expansion) is an irreversible process in thermodynamics in which a volume of gas is kept in one side of a thermally isolated container (via a small partition), with the other side of the container being evacuated.

In which process work is maximum?

The maximum work is done when the external pressure Pext of the surroundings on the system is equal to P, the pressure of the system. If V is the volume of the system, the work performed as the system moves from state 1 to 2 during an isobaric thermodynamic process, W12, is the maximum work as given by Eq.

What is adiabatic process example?

Adiabatic Process Example It is a process where there is a gas compression and heat is generated. One of the simplest examples would be the release of air from a pneumatic tire. Adiabatic Efficiency is applied to devices such as nozzles, compressors, and turbines. One of the good applications of the adiabatic process.

What is work done in free expansion process?

In free expansion process as there is no work done as there is no external pressure so work done is 0.

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