| 0.05 M Disodium edetate |
| 1.0 Scope: This procedure is applicable for preparation and standardization of 0.05 M disodium edetate solution. 2.0 Instrument/Apparatus: 2.1 1000 ml volumetric flask 2.2 500-ml beaker 2.3 100 ml graduated burette 2.4 2 ml and 10 ml volumetric pipette 2.5 100 ml volumetric flask 2.6 Magnetic stirrer 3.0 Reagents: 3.1 Disodium-edetate AR grade 3.2 Calcium carbonate AR grade 3.3 Dilute hydrochloric acid solution 3.4 Sodium hydroxide solution 3.5 Hydroxy naphthol blue AR grade To read this GTP click here Preparation of 1 M Sulphuric acid. 4.0 Preparation of reagents: Dilute hydrochloric acid solution: Dilute 8.5 ml of hydrochloric acid to 100 ml with distilled water and store in a well fitted transparent glass bottle. 5.0 Preparation: Dissolve 18.6 g of disodium-edetate in sufficient purified water to produce 1000 ml. 6.0 Standardization: Accurately weight about 0.20 gm of chelometric standard calcium carbonate, previously dried at 110 degree Celsius for 2 hours, and cooled in a desicator, transfer to a 500ml beaker, add 10 ml of purified water/water for injection and swirl to form a slurry. Covered the beaker with a watch glass and introduce 2 ml of dilute hydrochloric acid (HCl)from a pipette inserted between lip of the beaker and the edge of the watch glass. Swirl the contents of the beaker to dissolved the calcium carbonate(CaCO3). Wash down the sides of the beaker, the outer surface of the pipet, and the watch glass with water and dilute with purified water/water for injection to about 100 ml. While stirring solution, preferable with a magnetic stirrer, and about 30 ml of the 0.05 M disodium edetate solution from a 50 ml burette and titrate with 0.05M disodium edetate(EDTA) solution. Add 15 ml of sodium hydroxide(NaOH) solution add 300 mg of hydroxy naphthol blue indicator and continue the titration with the 0.05 M disodium edetate solution to a blue end point. Each ml of 0.05 M disodium edetate is equivalent to 100.09 mg of calcium carbonate. To read this GTP click here Preparation of 0.05 M Silver Nitrate. 7.0 Calculation : Wt. N=———————- V X 100.09 Where: N = molarity of disodium edetate solution Wt.= weight of Calcium carbonate in mg V = Consumed volumes of 0.05 M disodium edetate solution in ml. 8.0 Storage: Store in a well fitted plastic bottle. |
