Test Index

Thermodynamics

Section: Chemistry

© examsnet.com

Question : 14 of 40

Marks: +1, -0

In thermodynamics, the P – V work done is given by

w=-\int dV P_{\text{ext}}

For a system undergoing a particular process, the work done is,

w=-\int dV \left( \frac{RT}{V-b} - \frac{a}{V^2} \right)

This equation is applicable to a

[JEE Adv 2020 P1]

System that satisfies the van der Waals equation of state
Process that is reversible and isothermal
Process that is reversible and adiabatic
Process that is irreversible and at constant pressure

Solution:

The following expression of P-V work done

W=-\int P_{\text{ext}} dV

is applicable for reversible isobaric as well as isothermal and adiabatic process. If

P_{\text{ext}}

is substituted for a Vander Waals equation then it becomes

W=-\int \left( \frac{RT}{V-b} - \frac{a}{V^2} \right) dV

But it is not applicable for irreversible process which are carried out very fast. So work done is calculated assuming final pressure remains constant throughout the process

© examsnet.com

Go to Question:

Prev Question

Next Question