Question

The homoleptic and octahedral complex of Co²⁺ and H₂O has___ set of orbitals. unpaired electron(s) in the t_2g set of orbitals.

Answer 1

Correct Answer: 1

The homoleptic and octahedral complex [Co(H₂O)₆]²⁺ involves Co²⁺ with a d⁷ electronic configuration. In an octahedral field, the d-orbitals split into two sets: t_2g and e_g. For Co²⁺ in this complex, the electron filling follows the order dictated by Hund's rule and the octahedral crystal field splitting.

1. Electronic configuration of Co²⁺: [Ar] 3d⁷

2. Crystal field splitting in octahedral complexes splits the d-orbitals into lower energy t_2g and higher energy e_g sets.

3. In the [Co(H₂O)₆]²⁺ complex, electrons are filled into the t_2g and e_g sets according to the Aufbau principle and Hund's rule.

4. Distribution of the 7 d-electrons:

- t_2g level: 4 electrons

- e_g level: 3 electrons

5. The t_2g level has one unpaired electron.

6. The unpaired electron count in the t_2g set is 1, which falls within the range (1,1).

Therefore, the homoleptic octahedral complex of Co²⁺ with H₂O has 1 unpaired electron in the t_2g set of orbitals.