Question

[Ni(H\(_2\)O)\(_4\)]\(^{2+}\) on reaction with ethane-1,2-diamine forms violet color complex. Its formula and magnetic property respectively are

• A. [Ni(H\(_2\)O)\(_4\)(en)\(_2\)]\(^{2+}\), Paramagnetic nature
• B. [Ni(H\(_2\)O)\(_2\)(en)\(_2\)]\(^{2+}\), Diamagnetic nature
• C. [Ni(en)\(_3\)]\(^{2+}\), Paramagnetic nature
• D. [Ni(H\(_2\)O)\(_2\)(en)\(_2\)]\(^{2+}\), Paramagnetic nature

Hint:

Coordination complexes can show varied colors and magnetic properties depending on the metal ion and ligands involved, influencing their electronic structure and properties.

Answer 1

The Correct Option is C

Determine the formula and properties of the complex.

When Ni\(^{2+}\) is complexed with ethane-1,2-diamine (en), it typically forms a coordination complex where ethane-1,2-diamine acts as a bidentate ligand, replacing water molecules. The complete replacement of water by three en ligands forms [Ni(en)\(_3\)]\(^{2+}\), which is known for its violet color and paramagnetic properties due to unpaired electrons in the d-orbital of Ni\(^{2+}\).

Conclusion: The correct formula and properties are given by option (3) [Ni(en)\(_3\)]\(^{2+}\), confirming it as paramagnetic.