0.05 M EDTA Solution Preparation and Standardization

0.05 M EDTA Solution Preparation:

For 0.05 M EDTA Solution Preparation firstly Weigh accurately about 18.60 gm of disodium edetate and transfer to a 1000mL (1 Liter) grade A volumetric flask. Dissolve disodium edetate in sufficient purified water and makeup the volume with purified water. 

  • EDTA full form is  Edathamil; Ethylenediaminetetraacetic Acid; [Ethylenedinitrilo]tetraacetic Acid (C10H16N2O8 ).
  • EDTA is well known medication used in toxicity management & treatment due to heavy metal.

Standardization of 0.05 M EDTA

Method 1:

  • Weigh precisely about 0.10 g of calcium carbonate (CaCO3) and transfer to a conical flask.
  • Dissolve in 3.0 mL of dilute hydrochloric acid (10 %v/v  HCl) and 10.0 mL of purified water.
  • Boil for solution for about 10 minutes. Then cool it & dilute to 50.0 mL with purified water (CO2 free).
  • Add few drops of Erichrom Black T indicator by means of the dropper and Titrate the solution with 0.05 M disodium edetate (EDTA) till endpoint.
  • Record the volume of disodium edetate solution used during titration.
  • Same procedure shall be repeated for two more times.
  • Calculate the molarity of the solution by below-given formula.
Standardization and Preparation of 0.05 M EDTA


W = Weight of calcium carbonate (in gm).  

V   = Consumed Volume of disodium edetate solution (in mL).  

Method 2:

  • Weigh precisely about 0.40 gm granulated zinc (Zn), dissolve by moderate warming in 12 mL of dilute hydrochloric acid (HCl) and 0.05 mL of bromine water.
  • Boil to remove excess bromine, cool and sufficient water to produce 200.0 mL.
  • Pipette 20.0 mL of the resultant solution into a volumetric flask and nearly neutralize with 2M sodium hydroxide (2M NaOH).
  • Dilute to about 150.0 mL with purified water, add adequate qty. of ammonia buffer pH 10.0 to dissolve the precipitate and add 5.0 mL in extra.
  • Add 50.0 mg of mordant black-II mixture and titrate with the disodium edentate solution until the solution truns green.  


  • Each ml of 0.05M disodium edetate is equivalent to 0.00327g of Zn.
Standardization of 0.05 M EDTA
  • Determine the molarity in triplicate (3 Times) and calculate the average value (Result Variation should not be more than 0.2%.)
  • Standardized frequently: Every 15 days.  

Validity & Precaution of EDTA Solution:

  • 30 Days from the date of preparation and ideally Re-Standardization after15 days and when required.
  • Precaution: Check before use of the solution for the physical appearance (Mainly change in color), fungal growth and sedimentation.

Preparation of 0.1 M edetate disodium

  • Dissolve 37.22 gm of disodium EDTA in purified water to make 1000 mL

Preparation of 0.01 M EDTA

  • Transfer 100 mL of 0.1 M edetate disodium to a 1000 mL volumetric flask. Dilute with purified water to volume.

Standardization of 0.01 M Edetate Disodium as per USP:

  • Accurately weigh about 40.0 mg of secondary standard calcium carbonate, previously dried at 110°C for 2 hr in a oven and cooled in a desiccator, or dried according to the label instructions, transfer to a 400 mL beaker.
  • Protection the beaker with a watch glass, and add 4.0 mL of diluted hydrochloric acid (HCl- 10%v/v) from a pipet inserted between the lip of the beaker and the edge of the watch glass.
  • Wash down the sides of the beaker, the outer surface of the pipet, and the watch glass with water, and dilute with purified water to about 200 mL.
  • While stirring the solution, preferably with a magnetic stirrer, add about 30.0 mL of the edetate disodium (EDTA) solution from a 50.0 mL burette.
  • Adjust the solution with sodium hydroxide (NaOH) to a pH of 12.0 to 13.0, add 300 mg of hydroxy naphthol blue, and continue the titration with edetate disodium (EDTA) solution to a blue endpoint.


M= (gm CaCO3) × (1000) / 100.09 × mL EDTA

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