Question

QUESTION 2: 20 marks 20 points Kinetic studies on a solid-catalyzed reversible gas phase reaction, A B+C yielded the following rate law shown in Equation 1, which is a function of partial pressures of A, B and C i.e. PA, PB and PC from the experimental observations, a) Propose a dual-site mechanism which is consistent with the rate law given above, using the standard guidelines (8 marks) b) Making use of the proposed mechanism, derive a rate law. Compare with the rate law in Equation 1 and comment. (12 marks) * k(PA - Pepe -VA = (1 + KA PA + KBPg + KcPc)2 Equation 1: Experimentally determined Rate Law 1 Add File

Answer 1

A+S As Sop As + s = BS+cs (rate determining) a ) step BS 1 16 11 Bus CS CAS KA kot Surface reac" is the rate determining step all other reac" are cat equilibric, thes [as] PAS o (A) [5] PA [S] [BS] Pes [][s] Pe [s] Pes [c][5] Pels) let so be the total vacant Sites So= [s] + KAPA[s]+ kpPp [s] + Ke Pc (s) (5) - S. kee [cs 3 (1+ Kalat KB PB + kele

From surface reac - k. Pas (S) -Ya Kz Pos Pcs from eq 1, 2 & 3 -8=K, KA PA [s]²- Kz (KB P8) [s] (kPc ) [5] -8=k, KA PA (5)² - Kako kc PBPc [s] 2 from er -7 kika 2 PA Kaks ke PB Pc , so KIKA 11+ Kapat Ks Ppt Kepe)? -7 (PA X PB Pc) Kep (1+ KAPA+ kg Pot k Pc)² Any where, k = kika s² & Kegi kika kz ko kc