Predict the magnetic susceptibilities (para- or diamagnetic) and determine the number of unpaired electrons of each of the following complexes (consider C2O42- and H2O as strong field ligands which cause a large splitting of the d-orbitals).
K3[Cr(C2O4)3] * 3H2O
K2[Cu(C2O4)2] * 3H2O
K3[Fe(C2O4)3] * 3H2O
K3[Al(C2O4)3] * 3H2O