The two compounds $[Co(SO_4)(NH_3)_5]Br$ and $[Co(SO_4)(NH_3)_5]Cl$ represent:

The correct statement about the magnetic properties of $[Fe(CN)_6]^{3-}$ and $[FeF_6]^{3-}$ is

Number of complexes from the following with an even number of unpaired $d$ electrons is . . . . . . . . . .
$[V(H_2O)_6]^{3+}, \quad [Cr(H_2O)_6]^{2+}, \quad [Fe(H_2O)_6]^{3+}, \quad [Ni(H_2O)_6]^{3+}, \quad [Cu(H_2O)_6]^{2+}$
[Given atomic numbers: $V=23, Cr=24, Fe=26, Ni=28, Cu=29$]

Select the correct code of $TRUE$ and $FALSE$ for the given statements:
$(a)$ Peroxide ion as well as dioxygen molecule both are paramagnetic species.
$(b)$ In the set of isomers,$[Cr(H_2O)_6]Cl_3$ and $[CrCl(H_2O)_5]Cl_2 \cdot H_2O$,both compounds can easily lose water molecules on treatment with conc. $H_2SO_4$.
$(c)$ During the transformation $NO \to NO^+$,bond length decreases and magnetic behavior changes from paramagnetic to diamagnetic.
$(d)$ An ether is more volatile than an alcohol,both having the same molecular formula.

Which among the following complexes has the maximum number of isomers?

Select the diamagnetic coloured compound: