Nitrogen gas in an expandable container is cooled from 50.0C to 10.0C with the pressure held constant

Question:

Nitrogen gas in an expandable container is cooled from 50.0°C to 10.0°C with the pressure held constant at 3.00 X 105 Pa. The total heat liberated by the gas is 2.50 X 104 J. Assume that the gas may be treated as ideal
(a) Fond the number of moles of gas.
(b) Find the change in internal energy of the gas.
(c) Find the work done by the gas.
(d) How much heat would be liberated by the gas for the same temperature change if the volume were constant?