Using crystal field theory, draw energy level diagram, write electronic configuration of the central metal atom/ion and determine the magnetic moment value in the following :
(i) \([CoF_6]^{3-}, [Co(H_2O)_6]^{2+},[Co(CN)_6]^{3-}\) 
(ii) \([FeF_6]^{3-}, \ [Fe(H_2O)_6]^{2+}, [Fe(CN)_6]^{4-}\).

Using valence bond theory, explain the following in relation to the complexes given below :
\([Mn(CN)_6]^{3-}, [Co(NH_3)_6]^{3+}, [Cr(H_2O)_6]^{3+}, [FeCl_6]^{4-}\)
(i) Type of hybridisation    
(ii) Inner or outer orbital complex.    
(iii) Magnetic behaviour.    
(iv) Spin only magnetic moment value.

CoSO₄Cl.5 NH₃ exists in two isomeric forms 'A' and 'B' gives white precipitate with BaCl₂ but does not react with AgNO₃.  Answer the following questions.
(i) Identify 'A' and 'B' and write their structure formulas.    
(ii) Name the type of isomerism involved    
(iii) Give the IUPAC name of 'A' and 'B'.

What is the relationship between observed colour of the complex and the wavelength of light absorbed by the complex ?

Why are different colours observed in octahedral and tetrahedral complexes for the same metal and same ligands ?