Answer:
(a) 1 atm, 8.72 L and 298 K respectively.
(b) 1 atm, 16.72 L and 573.35 K respectively.
(c) 
Explanation:
Hello,
(a) In this case, considering that neon could be considered as an ideal gas, we can compute its volume as follows:

Thus, initial conditions of pressure volume and temperature are 1 atm, 8.72 L and 298 K respectively.
(b) Since the process was carried out at constant pressure, the work is defined as:

Thus, the final volume is:

And the final temperature is computed by considering the pressure-constant specific heat of neon (1.03 J/g*K) and the added heat:

Therefore, final volume is 16.72 L, final pressure is also 1 atm and final temperature is 573.35 K for this expansion process.
(c) Finally, the change in the internal energy is computed via the first law of thermodynamics:

Best regards.