Method for Preparation and Standardization of 0.1 (M) di-Sodium EDTA di-hydrate Solution

 Ø  Apparatus:-

·         250 ml conical flask

·         100 ml cylinder

·         50 ml burette

 

Ø  Reagents:-

·         di-Sodium EDTA dehydrate (A.R Grade)

·         Eriochrome Black T (EBT) Indicator

·         Magnesium Sulphate Heptahydrate (A.R. Grade)

·         pH 10 Ammonia Buffer Solution

 

Ø  Preparation of Solution:-

·         0.1 (N) di-Sodium EDTA dihydrate:- 

Weight accurately 37.224 g di-Sodium EDTA dihydrate and dissolve in 1L DM water.

·         Eriochrome Black T (EBT) Indicator:-

Dissolve 0.5 g of EBT and 5.0 g of hydroxylamine hydrochloride in sufficient methyl alcohol to produce 100 ml.

·         pH 10 Ammonia Buffer Solution:-

Dissolve 64.0 g of ammonium chloride in 600 mL of concentrated ammonia. Slowly and carefully add 400 mL DM water.

Ø  Procedure:-

Take accurately about 0.560 g Magnesium Sulphate Heptahydrate (A.R Grade) in a conical flask. Add approximately 50 ml DM water and shake gently until dissolution. Then add 5 ml to 10 ml Ammonia Ammonium Chloride Buffer (pH 10). Then titrate it with 0.1 (M) di-Sodium EDTA dihydrate solution with EBT indicator until the colour changes from red to blue.  

 

Ø  Calculation:-