a)

At constant pressure, the work done for gas to expand is given by:

W = PΔV

⇒W = 1.65 × 10⁵Pa × (0.320 – 0.110)m³= 3.46 × 10⁴J

b)

The total heat (Q) added to the system is used in work done and the remaining energy goes into internal energy.

ΔU = ΔQ-ΔW

⇒ΔU = 1.15 ×10⁵J – 3.46 × 10⁴J = 0.8 × 10⁵ J

c)

It does not matter that the gas is ideal or real because the work done would remain same. It would vary for real gases only at very high pressure.