Determination of Free Acidity as Hydrochloric Acid in Ferric Chloride Solution (RDM-5003)Procedure for Analysis
Ferric iron is complexed with Potassium Fluoride to prevent hydrolysis. The free acid is then titrated with standard Sodium Hydroxide to the Phenolphthalein end point.
- Sodium Hydroxide (NaOH) standard 0.10N solution.
- 33% Potassium Fluoride, neutralized to Phenolphthalein endpoint.
- 1. In 150 ml beaker, weigh accurately 1-2 grams of ferric chloride solution. Add 50 ml of distilled water.
- 2. Add 25 ml of Potassium Fluoride solution and mix.
- 3. Add few drops Phenolphthalein indicator
- 4. Titrate with 0.1N NaOH to first permanent trace of pink
% Free acidity as HCl = mls 0.1N NaOH x 0.365 grams of sample