Question

A frictionless piston-cylinder device contains 0.2 kg of air at 100 kPa and 27°C. The air is now

compressed slowly according to the relation P V^k = constant, where k = 1.4, until it reaches a final temperature of 77°C.

1. Sketch the P-V diagram of the process with respect to the relevant constant temperature lines, and indicate the work done on this diagram.
2. Using the basic definition of boundary work done determine the boundary work done during the process [-7.18 kJ].
3. Using the energy equation determine the heat transferred during the process [0 kJ], and verify that the process is in fact adiabatic.

Derive all equations used starting with the basic energy equation for a non-flow system, the equation for internal energy change for an ideal gas (Δu), the basic equation for boundary work done, and the ideal gas equation of state [P.V = m.R.T]. Use values of specific heat capacity defined at 300K for the entire process.

Answer 1