Question

Out of Ti³⁺, Cr³⁺, Fe²⁺ and Ni²⁺ ions, the one which is the most stable ion in aqueous solution is:

• A. Ti³⁺
• B. Cr³⁺
• C. Fe²⁺
• D. Ni²⁺

Hint:

Half-filled and fully filled d-orbital configurations offer extra stability in transition metal ions.

Answer 1

The Correct Option is B

Cr³⁺ (3d³) exhibits a half-filled t_2g configuration in an octahedral field. This configuration provides significant stability due to its symmetrical electron distribution and exchange energy, making Cr³⁺ the most stable ion in aqueous medium.