Preliminary Analysis of Free Hydrochloric Acid in Iron Chloride

Fall 1987

Preliminary Analysis of Free Hydrochloric Acid in Iron Chloride Solution

Mark Amrich and William Lehrer, Photofabrication Engineering, Inc.

Objective: To measure the free hydrochloric acid in a ferric chloride etching solution.

Principle: Ferric Chloride is mixed with potassium fluoride in a nonaqueous environment. The ferric & ferrous irons are precipitated out as ferric fluoride leaving the free hydrochloric acid to be analyzed by simple titration, using the millivolt scale on a ph meter.