preparation and standardization of 0.1M Disodium Edetate(EDTA)
Preparation: weigh accurately 37.2 g of disodium edetate and transfer in 1000 ml volumetric flask dissolve and dilute with purified water upto the mark.
Standardization:Weigh accurately about 0.8 gm of granulated zinc. dissolve by
gentle warming in 12 ml of dilute hydrochloric acid and 0.1 ml of bromine water. Boil to remove excess bromine, cool and add sufficient water to produce 200.0 ml. Pipette 20.0 ml of the
resulting solution into a flask and nearly neutralise with 2 M sodium hydroxide. Dilute to about 150 ml with water, add
sufficient ammonia buffer pH 10.0 to dissolve the precipitate and add 5 ml in excess. Add 50 mg of mordant black II mixture and titrate with the disodium edetate solution until the solution turns green.
1 ml of 0.1 Mdisodium edetate is equivalent to 0.00654 g of Zn.