Question No. 4: [15 marks] a. The following mechanism have been proposed for the pyrolysis of ethyl nitrate(C2H5ONO2) studied in a stirred flow reactor.. RY CHONO, -C2H30' + NO C2H50 CH3 + CH20 CH, + CH30NO, CH, NO, + CH30 2CH3O**_CH_CHO + C_H-OH Derive an expression for the rate of disappearance of ethyl nitrate that includes only the indicated rate constants and the concentrations of initial reactants and the final products. [11 Marks! b. The rate law for the thermal decomposition of ethane has been found as follows: .- (ICH Calculate the activation energy of the above reaction from the following activation energies Ex = 350 kI/ mol.E; = 170 kJ/mol, En = 30 kl/mol and Es = 0 kl/mol. The experimental value found for the activation energy of the themial decomposition of ethane is about 290 kJ/mol. Comment on the agreement between the experimental value and that predicted by the mechanism, [4 Marks! Support your answer with amations and calculation