Using Energy Concepts and the Ideal Gas Model
Two-tenths kmol of nitrogen (N2) in a piston-cylinder assembly undergoes two processes in series as follows:
Process 1−2: Constant pressure at 5 bar from V1 = 1.33 m3 to V2 = 1 m3.
Process 2−3: Constant volume to p3 = 4 bar.
Assuming ideal gas behavior and neglecting kinetic and potential energy effects, determine the work and heat transfer for each process, in kJ.
Step 1 of 3</p>
We are required to calculate the work and heat transfer.
Step 2 of 3</p>
The p-V diagram for the given process can be shown as below.
This process occurs at constant pressure.
The work done at constant pressure and changing volume process is,
From the relation,
For the process 2-3,
Therefore, from table A-23 for nitrogen,
At temperature 300 K, kJ/kmol
At temperature 400 K, kJ/kmol
The heat transferred in process 1-2 is,
Therefore, the heat transferred in the process 1-2 is -582 kJ.