Question

The mechanism below can be regarded as a variation of one

proposed by P. G. Blake and S. Ijadi-Maghsoodi [Int. J. Chem. Kinet., 15, 609–618 (1983)] for the thermal decomposition of methyl isocyanate. Trace quantities of CH4 and HCNO are

present in the final products, but the primary product compo- sition is consistent with the stoichiometry

CH3NCO → HCN+H2 +CO

Derive an expression for the rate of disappearance of methyl isocyanate that includes only the indicated rate constants and the concentrations of species appearing in the primary stoichiometric equation. Do not make the long-chain approximation until you have developed the indicated expression. At this point you may simplify this expression as appropriate to determine whether or not this mechanism is consistent with the experimental observation that this reaction is ( 3∕2)-order in CH3 NCO. State explicitly any other assumptions that you make in arriving at your final result.

Answer 1