Estimation of Magnesium Sulfate by Complexometric Titration

Estimations of magnesium sulfate by complexometric titration involves titrating with EDTA using Eriochrome Black T as an indicator to determine magnesium content.

Introduction of Estimation of Magnesium Sulfate by Complexometric Titration:

• Estimation of Magnesium Sulfate by Complexometric Titration In pharmaceutical analysis, the estimations of magnesium sulfate (MgSO₄) is done using complexometric titration with EDTA as the titrant. This method relies on the formation of a stable complex between EDTA and magnesium ions (Mg²⁺).

Apparatus and Reagents:

1. Burette
2. Erlenmeyer flask
3. pH meter or pH indicator
4. Magnesium sulfate solution (sample)
5. Standard EDTA solution (0.01 M)
6. Buffer solution (pH ~10)
7. Eriochrome Black T indicator (optional)

Procedure of Estimation of Magnesium Sulfate by Complexometric Titration:

1. Preparation of Sample:

   • Weigh a sample of magnesium sulfate, dissolve it in distilled water, and transfer it to an Erlenmeyer flask.

2. Prepare EDTA Solution:

   • Use a standard EDTA solution (typically 0.01 M).

3. Buffering:

   • Add a buffer solution to the sample to maintain a pH of ~10.

4. Add Indicator (optional):

   • If using Eriochrome Black T, add a few drops. The solution will turn pink due to the presence of magnesium ions.

5. Titration:

   • Titrate the magnesium sulfate solution with the EDTA solution from the burette.
   • As EDTA complexes with Mg²⁺, the solution’s color (pink if using Eriochrome Black T) will remain until all magnesium ions are bound.

6. Endpoint Detection:

   • The endpoint is reached when the color changes, typically from pink to blue (if using Eriochrome Black T), or there is a noticeable color change.

7. Record Volume:

   • Note the volume of EDTA required to reach the endpoint.

Calculations:

• Amount of MgSO₄ (in grams):
• The factor of 2 accounts for the reaction stoichiometry, as each Mg²⁺ ion reacts with one mole of EDTA.