Specify the number of unpaired electrons in [Ni(H₂O)₆]³⁺ (weak field).

Question

Quizplus · Accepted Answer

The coordination number of Ni is 6, so there are 6 ligands, including H₂O, ₆, and one unknown ligand denoted as X. First, we need to determine the oxidation state of Ni. We can set up an equation: 1 Ni + 1 X + 12 S from H₂O + 16 S from ₆ + 13+ = 0 (charge of the ion) Simplifying, we get: 1 Ni + 1 X + 28 S = -13 Since each ligand in the coordination sphere of Ni has a charge of -1, the charge of Ni must be +3 to balance the overall charge of the complex. Now we can determine the electronic configuration of Ni3+. The electron configuration of Ni in its ground state is [Ar]3d84s2, so Ni3+ has lost 3 electrons and the electronic configuration becomes [Ar]3d7. In a weak field ligand environment, the electrons in the d orbitals have low energy, and will fill the lower energy orbitals before pairing up. The three unpaired electrons will occupy three of the five d orbitals in the Ni3+ ion. Therefore, the number of unpaired electrons is 3.

Specify the Number of Unpaired Electrons in [Ni(H2O)6]3+ (Weak Field)

Specify the Number of Unpaired Electrons in [Ni(H₂O)₆]³⁺ (Weak Field)