An insulated piston-cylinder device contains 1 L of saturated liquid water at pressure of 150 kPa. An electric resistance heater inside the cylinder is now turned on, and 2869.47 kJ of heat is transferred to the water. The inside H2O pressure maintains constant at 150 kPa during the process. Determine: the entropy change of the water during this heating process, in kJ/K.

Explanation:

In this problem,

we will determine the enthalpy at the end of heat input and we get the condition is the super heated state.

so the entropy change will be due to latent heat at 150 kPa and also due to temperature change at the super heated state.

All the temperature, enthalpy is evaluated with the help of the steam table.

mass is calculated with the help of a specific volume at initial condition.

see image below

3 1/4 %

explanation: