Question

W 2. One mole of an ideal gas initially at 37°C and 2 bar pressure is heated and allowed to expand reversibly at constant pressure until the final temperature is 287°C. For this gas, Cum = 2.5R, constant over the temperature range. a. Derive related thermodynamic equations (q, w, U, and H) for an ideal gas, when the temperature is changed (5 points). b. Calculate w (work done on the ideal gas), 9 (the amount of heat absorbed by the ideal gas), AU, and AH for the process (5 points).

Answer 1

a) For adibatic process ( constant pressure) there is no heat excahage.

Thus,

q=0

Now,

7+) 7 W: - K -p+1 V₂ - VI -(x-1) -7+) ๆ Wz K V₂ -V") (2-) 1 ) 7 W = K₂ V 2 V2 - KV. Vi (7-1

Now, O dq=durdw for, adiabatic pro .: du= d W rocess aq Also, du= nCudT = now(Tz - T)

d H= dut a(PV) 7 dH = du RAT + d H = Cudi that 7 dn = dT (Cath) I dH = c d a du = Cp CT₂ - 3
b)
DU= 1 mol x 25 x 8,314 T AU= nadT kmal X nok 7 TOU = 5.196 KT

DH = nCpd T ЭДИ: 1 mgl x3.rt хир и 2 Ди 3.5x2.31ЧX къ ЭДИ: 1.2 15 кг