An ideal gas contained in a piston cylinder undergoes two processes.

The first process is a polytropic process with n = -1 which begins with p_1 = 2 bar, V_1 = 4 m^3 and ends at V_2 = 2 m^3.

The second process is at constant pressure and ends at V_3 = 1 m^3.

Calculate the work, in kJ, for the second process.