(i) What type of isomerism is shown by the complex [Cr(H₂O)₆]Cl₃ ?

(ii) On the basis of crystal field theory, write the electronic configuration for d⁴ ion if _o > P.

(iii) Write the hybridization and shape of [CoF₆]^3-. (Atomic number of Co = 27)

(i) Solvate (hydrate) isomerism is shown by the complex [Cr(H₂O)₆]Cl₃ due to presence of 6 H₂O ligands.

(ii) For electronic configuration of d⁴,

If _o > P,

Then the first 3 electrons will occupy lower t_2g orbital and then the 4^th electron would not be able to go to higher e_g orbital because pairing energy is less than the energy separation (CFSE) and a low spin complex is formed.

Therefore, electronic configuration will be t_2g⁴e_g⁰.

(iii) Hybridization and shape of [CoF₆]^3-:

Co is in +3 oxidation state so its electronic configuration will be Co: 3d⁷4s²

Co³⁺: 3d⁶4s⁰

Since, F^- ions are weak field ligands so they are not able to pair the electrons and outer orbitals are used in hybridization.

Therefore, hybridization and shape of [CoF₆]^3- is sp³d² and octahedral respectively.