Answer
$ W= 1.25 kJ $ . The positive sign indicates that the gas is expanding.
Work Step by Step
The work done for adiabatic process in step $2 \rightarrow 3 $ Since the gas is an ideal gas, according to the 'first law of thermodynamics'.
$\Delta E_{int} = Q - W$ when Q = 0 in adiabatic,
$ W= -\Delta E_{int} $
Taking $\Delta E_{int} $ from (h)
$ W= 1.25 kJ $. The positive sign indicates that the gas is expanding.
