Preparation and Standardization of 0.1 M Disodium Edetate (EDTA)

Disodium Edetate Solution Preparation

• Take about 100 ml of water in a cleaned and dried 1000 ml volumetric flask.
• Add about 37.2 gm of Disodium Edetate with continues stirring. 
• Add more about 700 ml of water mix. 
• Make up the volume 1000 ml with water. Mix the solution thoroughly. 
• Keep the solution for at least one hour and then carry out the standardization.

Related: Determination of Shelf Life of Solutions in Laboratory

Disodium Edetate Solution Standardization

• Weigh accurately about 400 mg of Calcium Carbonate.
• Previously dried at about 110°C for about 2 hours.
• Transfer it in a cleaned and dried 500 ml conical flask and add about 10 ml of water with gentle stirring to form the slurry. 
• Dissolve the carbonate in 2 ml of dilute hydrochloric acid and shake well until it dissolves.
• Add 100 ml water through the inner surface of the flask with the stirring of the solution.
• Add 30 ml of 0.1 M Disodium Edetate (prepared) from the burette with constant stirring.
• Add 15 ml of Sodium Hydroxide solution with constant stirring.
• Add 300 mg of Hydroxy Naphthol Blue solution as an indicator. 
• Add 0.1 M Disodium Edetate (prepared) with constant stirring and titrate it until the solution gives a blue color.
• Calculate the molarity by the following formula:

                 W x 1000
M = ----------------------
               BR x 100.09