Using the Peng-Robinson equation of state, calculate the work needed in (kJ/mol) for a steady-state flow reversible adiabatic compression of gaseous FREON-12, a refrigerant, from a pressure of 0.75 MPa and temperature of 325 K to a pressure of 2 MPa.

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.