A horizontal cylinder equipped with a frictionless piston contains 785 cm3 of steam at 420.0 K and 125 kPa. A total of 106.2 J of heat is transferred to the steam, causing the steam temperature to rise and the cylinder volume to increase. A constant restraining force is maintained on the piston throughout the expansion, so that the pressure exerted by the piston on the steam remains constant at 125 kPa. The specific enthalpy of steam at 125 kPa varies with temperature approximately as