Which one of the following complex ions possesses ionisation isomerism?

Of the following complex ions,which is diamagnetic in nature?

Identify the homoleptic complexes with an odd number of $d$ electrons in the central metal ion.
$(A) \ [FeO_4]^{2-}$
$(B) \ [Fe(CN)_6]^{3-}$
$(C) \ [Fe(CN)_5 NO]^{2-}$
$(D) \ [CoCl_4]^{2-}$
$(E) \ [Co(H_2O)_3 F_3]$
Choose the correct answer from the options given below $:$

What is the magnetic moment value of $Ni^{2+}$ in an aqueous solution in Bohr Magnetons? (Atomic number: $Ni = 28$)

Total number of stereoisomers of $[Co(acac)_2BrCl]^{\ominus}$ are

Which of the following coordination compounds would exhibit optical isomerism?