The Hydrolysis of Propionitrile in Concentrated Hydrochloric Acid Solutions

The hydrolysis of propionitrile has been studied in aqueous hydrochloric acid solutions from 0.5 to 10 N and over a range of temperatures at six acid concentrations. The rate of hydrolysis as measured by ammonia formation is dependent upon the decomposition of the intermediate amide at acid concentrations above 4 N. The system represented by nitrile [Formula: see text] amide [Formula: see text] acid affords a good example of consecutive, irreversible unimolecular reactions over the complete range [Formula: see text] (below 4 N) to [Formula: see text] (above 11 N). A marked increase in rate with increasing acid concentration is accounted for in large measure by a decrease in observed activation energy of 6.7 Cal. over the range 1 to 10 N.