Final answer:
To calculate the work done by Refrigerant 134a in a piston-cylinder assembly, data on the pressure and volume changes are required, which are not provided in the question. Without additional information or a thermodynamic diagram, a precise numerical answer cannot be given.
Step-by-step explanation:
Work Done by Refrigerant 134a in a Piston-Cylinder Assembly
The student's question pertains to the calculation of work done by Refrigerant 134a during its heating process in a piston-cylinder assembly. Since we are dealing with thermodynamics, specifically the expansion work done by a vapor, we would need more information to calculate this precisely. Typically, the work done (W) on or by a gas during expansion or compression can be found using the following relationship:
W = P × ΔV, where P represents the pressure and ΔV the change in volume.
However, without information about the pressures or volume changes involved in this process, we cannot calculate the work done using this equation. In a real-world scenario, you would refer to the saturation tables or thermodynamic properties charts for Refrigerant 134a at the specified temperature once you know the volume change to calculate the exact work done. Additional information about the process, such as is it at constant pressure or volume, would also be required to carry out this calculation.
If it is a constant pressure process, you would find the final specific volume at 145 degrees Celsius from the saturation table for Refrigerant 134a, and the work done would be the product of the pressure and the change in specific volume. If it's not a constant pressure process, then knowing the process details or having a pressure-volume diagram would be necessary.
Without the pertinent data or a proper thermodynamic process specified, it is impossible to provide a numerical answer to the question of evaluating the work in kJ/kg for Refrigerant 134a heating to 145 degrees Celsius.