Date: 31st october 2013
Name of the experiment: Identification of basic radical ( Al3+ & Mg2+ ) from supplied marketed dosage form
To identify basic radical ( Al3+ ,Mg2+ ) from supplied marketed dosage form.
Apparatus and reagents: Test tube
Disodium hydrogen phosphate
Preparation of the sample:
Ten of marketed products (tablets/ capsule) is taken and crushed in mortar pastle. This powder is used as a sample through out the experiment. Sample is taken, then dilute HCl is added, when dissolved the solution then filtered the sample, which is a stock solution.
Test for Magnesium
20ml of stock solution is taken in a flask and then 10mg of NH4Cl, 10 mg of NH4OH and excess disodium hydrogen phosphate solution is added. Then shaken and rubbed the wall of test tube. If white ppt is formed the Mg2+ is present.
Mg2+ + NH4Cl + NH4OH + Na2HPO4 →Mg(NH4)PO4 ↓ + Na+ + H2O Magnesium Ammonium Phosphate
Test for Aluminum:
Taking 20ml of stock solution in a flask & then added 10ml of NH4OH.Then a white gelatinous ppt is formed which indicates the presence of Aluminum.
Al3+ +NH4OH→Al(OH)3↓+ +NH4
Taken 20ml of stock solution ina flask & then add 10ml of sodium hydroxide solution slowly, a white gelatinous ppt is formed.
Al3+ +NaOH → Al(OH)3↓+Na+ Then more NaOH is added to dissolve the ppt.
After sometimes added AlCl3 & Cobalt nitrate, then a blue ppt observed.
Al3+ +Co(NO3)2+NH4Cl→Co(AlO2) ↓ Discussion: The name of the experiment is identification of basic radical ( Al3+, Mg2+) from supplied marketed dosage form. These reactions are known as precipitaion and we identified these basic radicals by observing the color of the precipitate formed from the experiment. White precipitate indicates the presence of Mg2+, which is Magnesium ammonium phosphate and gelatenious white precipitate indicates the presence of Al3+ which is Al(OH)3. Since this experiment was a qualitative experiment rather than quantitave experiment we were less careful about the measurement of reagents and our main focus on the precipitate's color. But we had to crush the tablest with mortar pastle into powder because the size of the tablet was big so crushing it made the surface area higher for dissolving. Initially the solution was white cloudy but after a while we saw that the white precipitate deposited in the bottom of the test tube
1. Acid should be added drop wise.
2.Contamination should be avoided.
3.All the apparatus should be washed properly with distilled water before starting the experiment.
4.We should wear gloves while doing the experiment.
5. we should use fume hood while adding ammonium hydroxide to avoid the toxic fumes.