Titration of Chlorides

Potentiometric Determination of Chlorides Using Automatic Titrators

Chloride determination is a fundamental analytical task, especially in fields such as environmental protection, pharmaceuticals, and food analysis.

Chloride analysis plays a crucial role in various industries due to its widespread presence. The potentiometric titration method offers a reliable and accurate way to determine chloride concentrations. Silver nitrate (AgNO3) serves as the titrant, and a silver electrode is used for indication. 

he following equipment is essential for chloride titrations:

1. Titrator with DET Mode: The automatic titrator facilitates precise and efficient titrations.
2. Burets: Use either a 10 mL or 20 mL buret, depending on the titrant and chloride concentration in the sample.
3. Stirrer: Ensures proper mixing during the titration process.

Electrodes

Select the appropriate electrode based on the sample’s chloride content:

• Ag-Titrode or AgCl RG electrode: Suitable for general applications.
• Combined Ag-ring electrode (AgCl 65 ): Offers versatility.
• Separate Ag electrode: Useful for specific  rare cases.

1. Sample Preparation:
   • Prepare the sample according to its type and chloride content.
2. Titer Determination:
   • Weigh, pipette, or dispense the appropriate amount of NaCl or KCl standard.
   • Add c(HNO3) = 2 mol/L or c(H2SO4) = 1 mol/L and approximately 60 mL distilled water.
   • Immerse the electrode(s) and titrate using c(AgNO3) as the titrant.
   • Adjust the mV measuring range as needed.

Reagents and Solutions

• Distilled Water: Used for dilution purposes.
• Titrant (c(AgNO3)): Concentration varies (0.001 to 0.1 mol/L).
• Acidifying Solution (c(HNO3) or c(H2SO4)): For adjusting pH.
• Standard Potassium Chloride (c(KCl)): or Dried Sodium Chloride: .
• in some cases there is an additive of Polyvinyl Alcohol