Problem- when 200 mol of o2 treated as ideal are heated at

Question

Problem- When 2.00 mol of O2 (treated as ideal) are heated at a constant pressure of 4.00 atm, its temperature increases from 260 K to 285 K. Knowing that the molar heat capacity of O2 at constant pressure is 29.4 J•K-1•mol-1,

calculate:

(a) The heat

(b) The change in enthalpy

(c) The change in internal energy

I just need a general explanation of it please- Thanks!