$[Co(NH_3)_4Cl_2]^+$ exhibits

Total number of cis $N-Mn-Cl$ bond angles (that is,$Mn-N$ and $Mn-Cl$ bonds in cis positions) present in $cis-[Mn(en)_2Cl_2]$ is: $(en = NH_2CH_2CH_2NH_2)$

Which of the following has the maximum paramagnetism?

The complex which has facial $(fac)$ and meridional $(mer)$ isomers is
(Given: $py = \text{pyridine}$ and $en = H_2N-CH_2-CH_2-NH_2$)

Which of the following ligands is able to form linkage isomers?

Identify the types of isomers shown in the structures $(i)$ and $(ii)$: