A Comparison of Steady State Procedures and Equilibrium Conditions in the Reversible Reaction

7 A Comparison of Steady State Procedures and Equilibrium Conditions in the Reversible Reaction 

Many complex reactions involve a reversible step followed by one or more other steps. If the intermediate(s) are present in steady state concentrations, then the steady state analysis will give a general procedure for deducing the rate expression. If the intermediate(s) are present in equilibrium concentrations, an equilibrium analysis is appropriate. But if the intermediate ) are not in either of these two categories, analysis becomes very complex (Sections 3.22 and 8.4). A comparison of the predicted and observed rate expressions can give considerable insight, e.g. Problem 6.4 above, and Problem 6.5 below. 

This problem focuses on the difference between steady state methods and the assumption of a pre-equilibrium for a reaction where the first two steps are reversible. 

Question. The following mechanism is common to both inorganic and organic reactions  

Now assume that the reversible reaction is at equilibrium, and deduce the rate expression. 

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