On the basis of VB theory explain the nature of bonding in ` [Co(C_2O_4)_3 ]^(3-)`

Explanation

`[Co(C_2O_4)_3]^(3-) `
outer electronic configuration ` -3d^(7) 4s^(2) ` Co in G.S.
` (##SUR_CHE_XII_V01_C05_E02_028_S01.png" width="80%">
Cobalt exits in +3 oxidation state in the given complex
` Co^(3+) ` in excited state
` (##SUR_CHE_XII_V01_C05_E02_028_S02.png" width="80%">
Oxalate is a weak field ligand .So no pairing of 3d orbitals occurs
` Co3+ "in " [Co(C_2O_4)_3]^(3-) `
` (##SUR_CHE_XII_V01_C05_E02_028_S03.png" width="80%">
hybridisation : `sp^(3) d^(2) `
geometry: Octahedral
Magnetic character : Since it has 4 unpaired electron .The complex is paramagnetic