Exams › JEE Main › Chemistry

When Ethane-1,2-diamine is added progressively to an aqueous solution of Nickel (II) chloride, the sequence of colour change observed will be : (1) Pale Blue → Blue → Green → Violet (2) Pale Blue → Blue → Violet → Green (3) Green → Pale Blue → Blue → Violet (4) Violet → Blue → Pale Blue → Green

1. Pale Blue → Blue → Green → Violet
2. Pale Blue → Blue → Violet → Green
3. Green → Pale Blue → Blue → Violet
4. Violet → Blue → Pale Blue → Green

Correct answer: Green → Pale Blue → Blue → Violet

Solution

The correct sequence reflects the changes in the coordination environment of the nickel ions as ethane-1,2-diamine is added, leading to the formation of different complexes that exhibit distinct colors, starting from green and transitioning through pale blue, blue, and finally violet.

Related JEE Main Chemistry questions

• When sodium hydroxide is introduced into an aqueous Zn2+ solution, a white precipitate forms, and this precipitate dissolves when more NaOH is added. In such a solution, zinc is present in the:
• When excess ammonia is added to a copper sulphate solution, a deep blue colour appears because of the formation of which species?
• In the nitroprusside ion, iron and NO are present as Fe$^{2+}$ and NO$^+$ instead of Fe$^{3+}$ and NO. These two formulations can be distinguished by
• In the brown ring test for nitrite and nitrate ions, the characteristic brown ring is produced because a complex ion is formed with which formula?
• What is the spin-only magnetic moment, expressed in Bohr magnetons (μB), for Ni²⁺ in aqueous solution? (Atomic number of Ni = 28)
• Silver chloride dissolves in aqueous ammonium hydroxide because it leads to the formation of which species?

⚔️ Practice JEE Main Chemistry free + battle 1v1 →