Coordination Compounds Part 1

(I) Under weak field ligand, octahedral Mn(II) and tetrahedral Ni(II) both the complexes are high spin complex.
(II) Tetrahedral Ni(II) complex can very rarely be low spin because square planar (under strong ligand) complexes of Ni(II) are low spin complexes.
(III) With strong field ligands Mn (II) complexes can be low spin because they have less number of unpaired electron (unpaired electron =1 )
While with weak field ligands Mn(II) complexes can be high spin because they have more number of unpaired electron (unpaired electron =5 )
(IV) Aqueous solution of Mn(II) ions is pink in colour.