When we add a large amount of etilendiamine to a solution NiSO4 a lila precipitate is observed, what is this precipitate)
The lilac precipitate observed when adding a large amount of ethylenediamine to a solution of NiSO4 is nickel(II) ethylenediamine complex, also known as nickel ethylenediamine complex.
Ethylenediamine (C2H8N2) is a bidentate ligand, meaning it can form two coordinate bonds with a metal ion. In this case, it forms coordinate bonds with the nickel ions present in the NiSO4 solution. The resulting complex is a coordination compound where the nickel ion is centered in a coordination sphere of ethylenediamine ligands.
To confirm the identity of the precipitate as nickel ethylenediamine complex, you can perform further tests. One way to do this is by carrying out a solubility test. You can dissolve a small amount of the precipitate in water and add dilute hydrochloric acid (HCl) or ammonium hydroxide (NH4OH). If the precipitate dissolves in HCl but reprecipitates upon addition of NH4OH, then it is likely to be nickel ethylenediamine complex. Additionally, you can perform spectroscopic techniques such as UV-Visible spectroscopy or infrared spectroscopy to analyze the compound's absorption spectrum, which can provide further evidence of the formation of the complex.
It is important to note that working with chemicals should be done with caution. Proper safety precautions and handling protocols should always be followed when dealing with potentially hazardous substances.