Determination of Free Nitric Acid in UNH Solutions, Problem Assignment No. 208-X2A, Progress Report (open access)

Determination of Free Nitric Acid in UNH Solutions, Problem Assignment No. 208-X2A, Progress Report

Technical report abstract: Since UNH is a highly dissociated compound which ionizes to NO3 and (UO2), the latter ion being very weakly basic, a solution of pure UNH is quite acid (pH about 3). It is possible to titrate to a phenolphthalein and point with standard caustic solution and obtain a figure which represents the free acid plus the NO3 from the the UNH. However, titration of the free nitric acid alone in such a solution presents quite a problem. By precipitating and removing uranium from solution by means of potassium ferrocyanide, the residual free acid may be titrated directly by means of standard caustic using either methyl red or phenolphthalein indicators, with an error of less than 4%. A method is given to determine formic acid, should that acid be present in the mixture.
Date: April 21, 1944
Creator: Parlour, A. K. & Hammond, C. W.
System: The UNT Digital Library