Answer to Question #109919 in General Chemistry for Akash Sharma

Question

An aqueous solution of NiSO4 is green in colour which turns deep blue on addition of
ethylenediamine.

Answer 1

An aqueous solution of NiSO4 is green in colour which turns deep blue on addition of

ethylenediamine because of the formation of [Ni(en)₃]SO₄ .

$Ni(SO_4)+3en->[Ni(en)_3]SO_4$

Green Deep blue

NiSO₄ absorbs red and green color is visible whereas [Ni(en)₃]SO₄ containing a strong ligand absorbs orange and blue color is visible.