Question

Gaseous ozone undergoes decomposition according to the stochiometric equation: 203(g) →302 (g) Two alternative mechanisms have been proposed to account for this reaction. Mechanism 2 03 302 bimolecular, rate constant k Mechanism II 03 02 + fast equilibrium, equilibrium constant K1 0+ 03 — 202 slow, rate constant k2 A. Derive rate laws for the formation of O2 for each mechanism. B. Thermodynamic measurements give standard enthalpies of formation for each of the following species at 298 K: species AH° 298 (kJ/mol) 02 (8) 0.0 03 (g) 142.3 O(g) 249.4 The observed activation enthalpy Aht for the overall reaction 203302 is 125.5 kJ/mol of O3. Sketch a curve of enthalpy per mol O3 versus reaction coordinate for each of the proposed mechanisms. Label the curves with numerical values for the AH between reactants, products, intermediates, and transition states. (Tinoco #33, p.375) Upload your answers to parts A and B as a file.

Answer 1

203.491 – 38443 Mechanism I ; 20 30 binolecular, rede constant k Mechanism fi 03 Fly to fast bindleclar, ky Ot 0₂ 202 slow, k Rato law for Mechanismi.kz SE203 302 Rate = $(0372 272 |d[03] = { a dr rate law is written in terms of meachaunts raised to the power of stoichiometric.coofficient Only when the Meaction ej elementary löne- step reaction). for a kimelesuar reaction the rused power is called Broder (this may or may nor be equal to the stoichiomemy)

I vaig Lrate law for Mechanism The Los us to step I taula) 0+03 12 200 step (slow) Kl = 102110) ki is equilibrium constant of first 10.TV Step reactiin agais, rate is written in terms of reachaile for the swewest step here slep I Rate = ky[0]3] Theinkimediat concentrulion can be intellžina ús heuns 01_kroucen meccharts LĪZILIMLLuonymoonco Rate = K2 k, 10₂] 10,1 (al H14101 = k10a]?1414/00K = Kike)

The meremedynamisc enthalpius aue as fourg - I AnkJ/mol O219) 0.0 03 ig) 142.3 Ocq) 249-4 ant is 125.5kJ/mol for 203 30₂ Mechanism I Mechanism a (263.03) 1267-8) 210 7 Ant (1423) v. Oslo) Expected wwels fan pele mole iz vs Reaction woordinate.(RC)