C

Step 1: Identify the given parameters:
Initial Temperature (T1) = 100ºC = 373 K
Initial Pressure (P1) = 600 kPa
Final Pressure (P2) = 100 kPa
Polytropic index (n) = 1.2

Step 2: Apply the polytropic process equation: P1 * V1^n = P2 * V2^n
Rearranging, we get:
V2 = (P1/P2)^(1/n) * V1

Step 3: Find Vi at initial conditions using the ideal gas law: V1 = (nRT)/P1 = (1 * 0.2968 * 373) / 600 = 0.184 m³/kg
Using the volume relationship: V2 = (600/100)^(1/1.2) * V1 = 6^(1/1.2) * 0.184 ≈ 0.405 m³/kg

Step 4: Calculate the work done using the formula for polytropic processes: W = (P2 * V2 - P1 * V1)/(n-1) = (100 * 0.405 - 600 * 0.184)/(1.2-1) = -153.79 kJ/kg (work is done on the system).

Step 5: Apply the first law of thermodynamics to find heat transfer: \Delta Q = W + \Delta U, where \Delta U = nC_v(T2 - T1).

Step 6: For nitrogen, Assume C_v = 0.743 kJ/kg.K. Find T2 using the ideal gas law with final conditions: T2 = (P2 * V2) / (R) = (100 * 0.405) / 0.2968 = 1365.19 K.

Step 7: Calculate \Delta U = nC_v(T2 - T1) = (1)(0.743)(1365.19 - 373) = 634.85 kJ/kg.

Step 8: Finally, heat transfer Q = W + \Delta U = -153.79 + 634.85 = 481.06 kJ/kg.
Thus, the work done is approximately -153.79 kJ/kg, and the heat transfer is about 481.06 kJ/kg.