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Isothermal Reversible And Isothermal Irreversible is considered one the most difficult concept.
16 Questions around this concept.
What will be the magnitude of work done when at of oxygen is expanded to occupy for times its original volume?
What will be if at
, I mole of an ideal gas was isothermally expanded from
to
?
A gas sample occupies at
and 1 bar pressure. If the gas undergoes an isothermal expansion to
, what is the final pressure?
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A gas of amount 0.2 mole undergoes a reversible isothermal compression at a constant temperature of . The gas is compressed from an initial volume of 10 liters to a final volume of 5 liters. Calculate the work done on the gas during the process.
A sample of one mole of a diatomic ideal gas initially occupies a volume of 8 liters at a temperature of The gas is allowed to expand isothermally to a final volume of 20 liters. Calculate:
Isothermal reversible and irreversible
Let us consider a cylinder fitted with a frictionless and weightless piston having an area of cross-section as 'A'. If the extemal pressure (P) is applied on this piston and the value of P is slightly less than that of the internal pressure of the gas When the gas undergoes a little expansion and the piston is pushed out by a small distance dx the work done by the gas on the piston is given by as
Isothermal irreversible expansion of an ideal gas
When a gas expands against a constant external . There is a considerable difference between the gas pressure (inside the cylinder) and the external pressure. The temperature does not change during the process.
Work done in Isothermal reversible expansion of an ideal gas
As a small amount of work done dW on the reversible expansion of a gas through a small volume dV against an external pressure 'P' can be given as
So the total work done when the gas expands from initial volume V1 to final volume V2 is given as
Here negative sign indicates work of expansion and it is generally greater than work in the irreversible process
As in such a case, the temperature is kept constant and internal energy depends only on temperature so it internal energy is constant.
Hence, during isothermal expansion, work is done by the system at the expense of heat absorbed.
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