Question

1. (a) Find the change in entropy when 2 kg of Oxygen at 600C are (30) mixed with 6 kg of Nitrogen at 400C in a rigid vessel. The
   initial pressure of each component is 103 kPa and remains
   the same for that of the mixture.

   (b) What is the amount of heat transferred during the mixing process?

   Given, Cv = 0.743 J/g.oK for Nitrogen and Cv = 0.659 J/g.oK for Oxygen.

Answer 1

२ Jl. K Cue 0.743 I + 32 9 mol Steb: 1 Cuiven, Mass of anygen, mar 2 kg Heat capacity at constant volume, G64433 M? Holes of Oz , 399 and 262.5 moles gok Molecular weight of O 3291 mel M109 *1000 2 g nog = 23.7 Ilmolok

R = Universal Gas Constant 1 p = G+ 20 G = 23.7 + 8.314 Go . 39.01 J/moln K oor temperature of O2, To, 600°C boot 273 Ton 873 K 2 2 Meless of Nitrogen, MNA 0.659 Ilmol. K 6 kg Cung 2 Molecular weight of Na, MNO 2 28 g/mol Moles of Na Na 6000 g 1, 289) mol M Ng 2 214.28 moles

G. 0.659 Inglik + 28 g/mol G. 18.45 Il malik G - G+R 18.45 +.8.314 96.74 Il mol. K 2 temperature of Na TNG 2 400 °C 2 400+ 273 Tag - 673 k constant pressure process at 103 kPa.

Step Let 't be the Equilibrium temperature of the mixture by Taking Energy Balance, Ton - T) (T-Tren] M107 MN CPN 2 cror 62.5 miles * 39:01 I (873-1] K 214.28 moles * molek 26.74 Il molok [T-673] K 1746.54.-27 2:5.73T - 3856.18 7.73T 2 5602.7 T 2 724.8 K

For an Ideal Gas, Enkopy change of System to as) System & lm Tz - R lm Pz Т) en P at constant pressure G = Heat Capacity T2, Ti = final cond Initial temperature Final and Initial Pressure P2, P, R Universal Gas Constant

nor Og Com Ton 62.5 mole * 32:01 Il mol: K 2 214.28 male & 26.74 /mol K Here Pope [constant Messure process] lim P₂ zo Enkopy change of Orygen, (as) lm lm 784.8 873 Entropy change of Nitragen, lm 124.8 673 2 – 372.2 J/ K O (AS) MNG CP Ng lm TN T

(As) 424.87 YIK Na Total Entropy change of mining (15) - (As)o + (AS) 2 -372.2 + 424.87 52.67 Ilk 2 (b) Heat transferred Equation can use any Qe nos og [ Toz - 7) = MN CPN (T-TNa] NO2 Con [Tog- 62.5 mole # 32.01 J/mol k 2 (873 – 784.8] K u 296.5 KI This i amount of Heat transferred during the process".