Please help me under stand this, for # 30 this question says (at constant volume). but when the volume is constant the pressure is constant and with that we can't solve for temp. I am so confused.

140 moles of a gas which has y - 1.31 expands from Vi = 0.5m to Vf = 1.8m following the relation P(V) - 2.0 x 10" Pam + 1.2 x 105 Pa m V (2) 30. What is Co, the molar specific heat at constant volume, for this gas? (a) 1.3R (b) 2.3R (c) 3.2R (d) 4.2R (e) 5.2R 31. What is the change in temperature during this process? (a) 198K (b) 308K (c) 327K (d) 460K (e) 506K 32. What is W, the work done by the gas during this process? (a) 1.24 x 105 J (b) 1.88 x 105 J (c) 2.42 x 105 J (d) 3.12 x 105 J (e) 4.36 x 105 J What is Q during this process? (a) 1.40 x 106J (b) 1.46 x 106J (c) 1.58 x 106J (d) 1.72 x 106 J (e) 1.94 x 106J