JEE Main 2025 Chemistry question
When Ethane-1,2-diamine is added progressively to an aqueous solution of Nickel (II) chloride, the sequence of colour change observed will be :
Answer: (3)
Solution
[Ni(H2O)6]2+ (green) progressively converts through [Ni(H2O)4(en)]2+ (pale blue) to [Ni(en)3]2+ (blue/violet) with successive en addition.