To calculate the work done by 5kg of saturated water vapor at 300kPa heated to 200°C, the relevant equations include the ideal gas law and the specific volume of steam at the given conditions. The process occurs at constant pressure, which simplifies the work calculation to W = P(V2 - V1). The specific volume values must be determined from steam tables for the initial and final states. The final work done by the steam can then be computed using these values. Accurate calculations require careful attention to the properties of steam at the specified pressures and temperatures.