What is the magnetic moment value of $Cr(CO)_6$ in Bohr Magneton units?

The calculated spin-only magnetic moments of $[Cr(NH_3)_6]^{3+}$ and $[CuF_6]^{3-}$ in $BM$,respectively,are (Atomic numbers of $Cr$ and $Cu$ are $24$ and $29$,respectively).

There are four complexes of $Ni$. Select the complex(es) which will be attracted by a magnetic field:
$(I) \ [Ni(CN)_4]^{2-}, \ (II) \ [NiCl_4]^{2-}, \ (III) \ [Ni(CO)_4]$
$(IV) \ [Ni(H_2O)_6]^{2+}$

The number of enantiomeric pairs possible for the complex having general formula $[M(AB)_3]$ with coordination number $6$ is

The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is

The magnetic moment of an octahedral homoleptic $Mn(II)$ complex is $5.9 \ BM$. The suitable ligand for this complex is: