Determination of Free Acid in Presence of Hydrolyzable Ions

Abstract

AN IMPORTANT and recurring problem is the determina-±\_ tion of the free acid in the presence of hydrolyzable ions such as iron, chromium, aluminum, etc., or mixtures of such ions.Direct pH measurements are impossible in solutions of high acid-

Analytical chemistry

“…A simple apparatus for conductimetric titration has been described.421 A conductimetric titration method has been proposed for the determination of free acid in the presence of hydrolysable salts, and is applicable both to very small aliquots of solution and to solutions of low concentration, so that it is recommended for the titration of highly radioactive solutions. 422 The sulphate titration with barium solution has been studied, and it is pointed out 423 that the conductimetric end-point and the true equivalence-point are not necessarily coincident, the former being affected by composition and concentration of the solution. Such divergence should be taken into account in precise work.…”

Determination of Free Acid in Presence of Hydrolyzable Ions

“…Pepkowitz, Sabol, and Dutina (5) found that nitric or sulfuric acid could be determined in the presence of large amounts of aluminum and lesser amounts of stainless steel components by complexing with fluoride and determining the acid-base end point by conductance measurement. The ratio of fluoride to hydrolyzable ion had to be kept within fairly narrow limits to ensure good end points and stoichiometric recovery of acid.…”