A cylinder with a piston contains 0.130 mol of nitrogen at 1.80x10^5 Pa and 290 K. The nitrogen might be treated as an ideal gas. The gas is first compressed isobaric ally to half its original volume. It then expands adiabatically back to its original volume, and finally it is heated isochoric ally to its original pressure.

1. Calculate the work done, the heat added, and the internal energy change during the final heating.

2. Calculate the work done by the gas, the heat added to it, and its internal energy change through the initial compression.

3. Calculate the work done by the gas, the heat added to it, and its internal energy change through the adiabatic expansion.