Question

( (4 pts) The first stage of the Ostwald process is heating ammonia gas with oxygen gas in the presence of a catalyst at 900 K and 5 atm to form nitric oxide gas and water vapor. Write the balanced chemical equation for this reaction. (g) (4 pts) Evaluate AG (k) for this reaction at 900 K. Is the reaction spontaneous under standard conditions at 900 K? (h) (8 pts) The second stage of the Ostwald process begins by oxidizing nitric oxide gas in oxygen gas to nitrogen dioxide gas. Then, the resulting nitrogen dioxide gas is absorbed by water to yielding nitric acid HNO,(aq) and some nitric oxide gas. These reactions are often carried out at-50°C (323 K) and atmospheric pressure. Write these two balanced chemical reactions. () (8 pts) Evaluate AG° (kJ) for each of these reactions at 323 K. Are these reactions spontaneous under standard conditions at 323 K? ) (4 pts) What is the total net balanced chemical equation for the second stage of the Ostwald process, which converts nitric oxide gas into nitric acid? (HINT: combine the two reactions from parts (h).)

Answer 1

HH ULO a fare write on this margin - a NH₃ to catalyst No +2H₂O 19) (9) Satu 19 9 Balancing N on bothsides : a=c. 3a = ad & ab = c+d let (a=a, e=2, d=3, b = 5/2 ) x2 a = 4, c=4, d=6, b =5. | 4 NH3 + 502 Catalyst, I 4 No + 6 H20 || 4 NO + 6 H₂O 5 atm | AG = AH - TAS AH = 2 stig – het hy - [4 x sub + bxoHel- [5x84 +4* ben] = (4x 490-4 + 6x – 241.8] - [5xo + 4X462) = a1089-2 + 184.8 900k No - 904.4 kg UJIAN Similarly Asº -54 x 210.6 +681888] - [5x2050 +4*143,9 - 1975.2 – 1795 = 180-2 / AG"=-904.4 kg - 900 K x 180-2 kJ Toto X 19" = -1066:58 x97 - - 10665 AGLO So, it is spontane

write on this margin On 323k Sepatu 2 Noz ig) 1 atm? Stage 2 t o (9) g) I a No2 (g) +6H₂O(l) IN balance: a-ced 19 +6H₂O(l) CHN e HNO₃ lag) tano, to balance 2a +6= 3c+ d e I'H' balance : abac So, a=36 c=2b d = b let b=1, d=1, car, a=3. 3 NO2 (g) + H₂0 (1) 323k 2 HNO₃ + No tam i) Adding ons ②x②, [2 no tor 3 NO2 + H20 2 NO. 7 x3 2HNO₃ + No] x2 6 NO + 302 6/NO2 6 NO2 + 2H₂O 4HNO₃ + 2No. 4 NO + 30₂ + 2H2O 4HNO₃ g) (9) (29)

this marg FORT WWW संध्या के अतिरिक्त कुछ fet 323 K is a Noo + 02 31 2002 sH - [2x - (2 x 60 cm +2% 04/03] - (2 x 33.8 - 12*90-4+ 2x0)] A#° - [67.6 - 180.8] AH = -113.2 kg As = [2 x A non- (2x058 No + 2x058 ] 3 [2 x 2405 - (2x 210-6 + 2 x 20503 ? 481 - (831-2) A5 - - 350.2 J/k AGⓇ - AH-TAS° = -113-2 kg - 323Kx - 350.247 AG = - 0.0854 kJ | AGCO So, spontaneous 3 Nog + H₂oU) 2 HNO3 + NO laps 9) AH - (2x -2066 +90-4) - (8x 33-8 +-285-2 AH = - 322.8 + 1944 = -138-4 kJ 1500 K WUJUIN AS = (2x 146.0+ 210.6) 502.6 - 651-6 = (3x 240.5 - 69.9) -149 Ik As = AGO = - 138.4 - 323 KX-149 kg AG = -90.273 kJ I AG Contanea