Analysis of Hydrochloric in Ferric Chloride Etchant RDM-5002

Analysis of Hydrochloric in Ferric Chloride Etchant (RDM-5002)

Procedure for Analysis Theory: This method describes the procedure for the electrometric determination of free acidity.
Reagents Required:

• 0.1N sodium hydroxide in lithium chloride solution:
• Dissolve 4.000 grams A.R. sodium hydroxide in 10M lithium chloride solution and dilute to 1 liter with the same.
• Saturated lithium chloride solution (about 10M):
• Dissolve approximately 610 grams of lithium chloride in demineralized water and dilute to 1 liter.
• MIBK: Methyl Iso-Butyl Ketone

Recommended Range for HCl 0 - 10 grams per Liter

Procedure:
Pipette a 5 ml aliquot of undiluted sample into 50 ml beaker and add 10 ml of saturated lithium chloride solution. Stir for a further 10 min. to complex the Ferric. Add 15 ml of MIBK. and stir for a further 10 min. to extract the complex. Titrate with 0.1N sodium hydroxide in lithium chloride using a pH meter to pH 4.0. This is t4.

Calculation:
Hydrochloric Acid in grams/liter = 0.73 x t4
Or: %HCL ≈ t4 X 0.052