The pentaamminenitrocobalt $(III)$ ion exhibits which of the following properties?

Write all the geometrical isomers of $[Pt(NH_3)(Br)(Cl)(Py)]$ and determine how many of these will exhibit optical isomerism.

$A$ compound absorbs light in the wavelength region $490-500 \,nm$. Its complementary colour is

The $d-$ electron configurations of $Cr^{2+}, Mn^{2+}, Fe^{2+}$ and $Co^{2+}$ are $d^4, d^5, d^6$ and $d^7$ respectively. Which one of the following will exhibit the lowest paramagnetic behaviour? (Atomic no. $Cr = 24, Mn = 25, Fe = 26, Co = 27$).

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

Magnetic moment $2.83 \ BM$ is given by which of the following ions?
(At. nos. $Ti = 22, Cr = 24, Mn = 25, Ni = 28$)