The magnetic moments of the complexes given below are in the order:
$I. [Ni(CO)_4]$
$II. [Mn(CN)_6]^{4-}$
$III. [Cr(NH_3)_6]^{3+}$
$IV. [CoF_6]^{3-}$

The number of possible optical isomers for $[Co(en)_2 Cl_2]^+$ is ....

Atomic numbers of $Cr$ and $Fe$ are $24$ and $26$ respectively. Which of the following is paramagnetic?

Which of the following represents a pair of enantiomers?

An octahedral complex with molecular composition $M \cdot 5NH_3 \cdot Cl \cdot SO_4$ has two isomers,$A$ and $B$. The solution of $A$ gives a white precipitate with $AgNO_3$ solution and the solution of $B$ gives a white precipitate with $BaCl_2$ solution. The type of isomerism exhibited by the complex is

$(a) \ CoCl_{3} \cdot 4 NH_{3}$
$(b) \ CoCl_{3} \cdot 5 NH_{3}$
$(c) \ CoCl_{3} \cdot 6 NH_{3}$
$(d) \ CoCl(NO_{3})_{2} \cdot 5 NH_{3}$
Number of complex(es) which will exist in $cis-trans$ isomerism is/are ....