A rigid tank contains 2.0 kg of superheated steam initially at temperature of 250 °C and pressure 0.5 MPa (state 1). Heat is added to the steam leading to a rise in temperature and pressure. The final pressure at state 2 is 1.0 MPa. Consider that the specific volume remains constant throughout the process as the tank is rigid.

Calculate final temperature and heat added. I can find enthalpy at state 1 from tables, but then I am stuck.

This can be approximated as ideal gas and using ideal gas equation P1v1/T1=P2v2/T2

(v1=v2) you can find out T2. Once you know T2 calculate heat transfer using Q=mcvdT.

You can verify this by using h-s plot (Mollier chart) or steam table. The answers should be close to above values.