Kinetics of ammonolysis

In reacting ammonia with organic compounds it is usually the practice to use a substantial excess of ammonia. Under this condition there is no appreciable change in concentration of ammonia compared to the other reactant, and the rate expression for the process becomes pseudo first order. Actually, the reaction is bimolecular in nature and involves the reaction of one molecule of ammonia with one molecule of the other reactant so tliat the second-order rate expression is more indicative of the actual mechanism. 

The terms C and C refer to the concentration of the two reactants, and k is the reaction-rate constant. 

Reactions of ammonia and organic compounds are effected in both vapor and liquid phases. The liquid-phase systems include anhydrous liquid ammonia, anhydrous ammonia in an organic diluent, and aqueous ammonia, occasionally in the presence of an organic solvent. 

Studies of the kinetics of the reaction have been concerned principally with the liquid-phase ammonolysis of esters and aromatic chloro compounds, presumably because the reactions are more cleancut and there is less tendency to form by-products. For example, in the ammonolysis of esters, the amide is essentially the only product, whereas with the reaction of aliphatic alcohols and ammonia an equilibrium mixture of mono-, di-, and trialkylainines is obtained. 

The reaction of esters and ammonia proceeds directly to the amide according to the following equation  

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The series of investigations carried out at the L. Ya. Karpov Physicochemical Institute by A. I. Shatenshtein, V. A. Pleskov, A. M. Monoszon, and others has been concerned with the properties of acid-base equilibria in liquid ammonia. Measurements have been made of the kinetics of ammonolysis catalysed by acids (Shatenshtein... 

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