Draw isomers of the complex ion `[Co(en)_(2)Cl_(2)]^(+)`

(i) Write the geometrical isomer of the complex [Co(en)_(2)Cl_(2)]^(+) . (ii) [NiCl_(4)]^(2-) is paramagnetic while [Ni(CN)_(4)]^(2-) is diamagnetic through both are tetrahedral . Why ?

(a) For the complex [Fe(CN)_(6)]^(3-) , write the hybridisation type, magnetic character and spin nature of the complex .(At. Number : Fe = 26) (b) Draw one of the geometrical isomers of the complex [Pt(en)_(2)Cl_(2)]^(2+) which is optically active .