The two complexes given below are $............$.

The number of geometrical isomers of the complex $[Co(NO_2)_2(NH_3)_2]$ is

The correct order of the number of unpaired electrons in the given complexes is
$A$. $[Fe(CN)_6]^{3-}$; $B$. $[FeF_6]^{3-}$; $C$. $[CoF_6]^{3-}$; $D$. $[Cr(oxalate)_3]^{3-}$; $E$. $[Ni(CO)_4]$
Choose the correct answer from the options given below:

Which of the following isomerism is not possible for complexes having molecular formulas:
$(i) \ Pt(SCN)_2 \cdot 3PEt_3$
$(ii) \ CoBr \cdot SO_4 \cdot 5NH_3$
$(iii) \ FeCl_3 \cdot 6H_2O$

Choose the complexes which are paramagnetic from the following:
$(i)$ $K_4[Fe(CN)_6]$
(ii) $K_3[Cr(CN)_6]$
(iii) $K_3[Fe(CN)_6]$
(iv) $K_2[Ni(CN)_4]$

The correct order of spin-only magnetic moment of the following complex ions is: (Given At. No. $Fe: 26, Co: 27$)