Determination of Free Acidity as Hydrochloric Acid in Ferric Chloride Solution RDM-5007

December 11, 2009
RD Chemical Company in Chemical Milling, Process

Determination of Free Acidity as Hydrochloric Acid in Ferric Chloride Solution (RDM-5007)

Procedure for Analysis

Theory:
Ferric iron is complexed with Potassium Oxalate to prevent hydrolysis. The free acid is then titrated with standard Sodium Hydroxide to an electrometric end point.

Reagents Required:

• Sodium Hydroxide, standard 0.10N solution.
• 33% Potassium Oxalate (anhyd) pH adjusted to 7.8.

Equipment Required:

• pH meter
• magnetic stirrer
• Buret

Procedure:

• 1. In 150 ml beaker, weigh 180 grams of Potassium Oxalate solution.
• 2. Add 10.0 grams Ferric solution.
• 3. Put pH probe into solution.
• 4. Titrate with standard NaOH to pH 7.8.

Calculation:
% Free acidity as HCl = mls 0.1N NaOH x 0.3645 grams of sample

RD Chemical presents these procedures in good faith, based on laboratory and field testing. Ultimate responsibility for propriety of use, however, must rest with the purchaser and user. RD Chemical Company recommends thorough testing of its products and procedures before use.

Article originally appeared on RD Chemical Company - Manufacturing Chemists (http://rdchem.com/).