Calculating work in a one-step expansion/compression

  • Thread starter Thread starter Footballer010
  • Start date Start date
  • Tags Tags
    Work
Click For Summary
SUMMARY

This discussion focuses on calculating work done during a one-step expansion/compression of an ideal gas under thermodynamic principles. The process involves 1 mole of gas transitioning from an initial pressure of 3 atm to a final pressure of 0.75 atm at a constant temperature of 25°C. The work can be calculated using the formula W = P(ΔV), where ΔV is derived from the initial and final volumes determined through the ideal gas law (PV = nRT) and Boyle's Law (P1V1 = P2V2). The discussion emphasizes that for net transitions, the intermediate step can be disregarded.

PREREQUISITES
  • Understanding of the Ideal Gas Law (PV = nRT)
  • Familiarity with Boyle's Law (P1V1 = P2V2)
  • Knowledge of thermodynamic work calculations (W = PΔV)
  • Basic concepts of irreversible processes in thermodynamics
NEXT STEPS
  • Study the application of the Ideal Gas Law in various thermodynamic processes
  • Explore advanced topics in irreversible thermodynamics
  • Learn about calculating work in multi-step thermodynamic cycles
  • Investigate the implications of temperature changes on gas behavior
USEFUL FOR

This discussion is beneficial for students and professionals in thermodynamics, particularly those studying ideal gas behavior and work calculations in irreversible processes.

Footballer010
Messages
14
Reaction score
0
Hello. I'm having problems with one thermodynamics. I've used several equations but I'm still unable to get the right answer. A push in the right direction would be helpful. Thanks.


Consider a process involving 1 mole of an ideal gas that takes place by the following pathway, at a constant temperature of 25oC:
P1 = 3 atm → P2 = 0.75 atm → P3 = 3 atm
Both steps occur irreversibly.

work=?
 
Chemistry news on Phys.org
W=P[delta]V

Boyle's Law: P1V1=P2V2

PV=nRTSo, use the ideal gas equation (PV=nRT) to solve for the initial volume of gas present. Then you can use Boyle's law to calculate the new volume after the change has occurred (the new volume is V2, the initial pressure is P1, etc) you can then multiply the new pressure by the CHANGE in volume (ie, the difference between V1 and V2) to get the work. Repeat process for the next step of the transfer. If you only need to calulate work for the net transition, completely ignore the middle step.
 

Similar threads

Thermodynamics: gas expansion formula or approximation error?
  • · Replies 2 ·
Replies
2
Views
1K
Thermodynamics - expansion, compression, work
  • · Replies 3 ·
Replies
3
Views
5K
Undergrad Joule-Thomson Expansion
  • · Replies 4 ·
Replies
4
Views
902
Entropy Change - Irreversible Isothermal Compression
  • · Replies 5 ·
Replies
5
Views
3K
Undergrad Why work is PdV and not (P+dP)dV in an isothermal process?
  • · Replies 6 ·
Replies
6
Views
952
Undergrad About Reversible vs Irreversible Gas Compression and Expansion Work
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Filling a rigid tire from a pressure regulated compressed air line
  • · Replies 67 ·
3
Replies
67
Views
6K
Confusion about the use of partial molar Gibbs free energy
  • · Replies 11 ·
Replies
11
Views
3K
Work and Volume in Adiabatic Expansion
  • · Replies 11 ·
Replies
11
Views
3K
Graduate Work done during adiabatic expansion on piston
  • · Replies 8 ·
Replies
8
Views
4K