Question

What is reversible isothermal expansion?

Answer 1

Hint :All reactions between molecules or atoms in an ideal gas are completely elastic, and there is no intermolecular force of attraction because the molecules in an ideal gas travel so quickly and are so far apart that they do not interact at all. In the case of real gas, intermolecular attractive forces are marginal. There is no such thing as ideal gas in nature.
Gases, on the other hand, behave well at high temperatures and low pressures. In an ideal gas, all internal energy is in the form of particle kinetic energy, and any variation in internal energy results in a change in temperature.

Complete Step By Step Answer:
Reversible isothermal expansion is a process where there is a rise in volume at a constant temperature. The operation is performed indefinitely slowly in theory, such that the microscopic reversal from the final state regenerates the original state exactly.
From the first law of thermodynamics , an ideal gas whose internal energy U is a function of temperature can be represented as:
 $\mathrm{\Delta }U=q_{rev}+w_{rev}=0$
Since, the temperature is constant. Hence, $\mathrm{\Delta }T=T_2-T_1=0$ .
Therefore, $w_{rev}=-\int PdV=-q_{rev}$
Where $q$ is heat flow
Here, the work done is calculated with respect to the system.
All the reversible isothermal $PV$ work $w_{rev}$ which is done by an ideal gas to expand was possible by reversibly absorbing heat $q_{rev}$ into the ideal gas.

Note :
There are countless isothermal processes in the fields of science and engineering. Depending on chemical reactions and mechanical applications, isothermal processes may be concerned. From isothermal titration calorimetric to making blasting agents and rocket propellants, there are countless numbers of isothermal processes for engineering applications.