The magnetic moment of $Cr(CO)_6$ is .....

Amongst $Ni(CO)_4$,$[Ni(CN)_4]^{2-}$ and $[NiCl_4]^{2-}$,which of the following statements is correct regarding their magnetic properties?

$Ni(CO)_4$ and $[Ni(NH_3)_4]^{2+}$ do not differ in

In a particular isomer of $[Co(NH_3)_4Cl_2]^0$,the $Cl-Co-Cl$ angle is $90^\circ$. This isomer is known as:

Select the correct code regarding the total number of stereoisomers for the following compounds:
$I. [Ma_3b_2c]^{n \pm}, II. [M(AB)_3]^{n \pm}, III. [Ma_2b_2c_2]^{n \pm}$
$I - II - III$

An octahedral complex of $M^{+3}$ with $NH_3$ and $NO_2^{-}$ ligands has four $M-N$ linkages and two $M-O$ linkages. Which type of isomerism will such a complex exhibit?