The number of geometrical isomers possible in triamminetrinitrocobalt $(III)$ is $X$ and in trioxalatochromate $(III)$ is $Y$. Then the value of $X+Y$ is $....$

The spin-only magnetic moment value of $M^{n+}$ ion formed among $Ni$, $Zn$, $Mn$, and $Cu$ that has the least enthalpy of atomisation is $........$ (in nearest integer). Here $n$ is equal to the number of diamagnetic complexes among $K_2[NiCl_4]$, $[Zn(H_2O)_6]Cl_2$, $K_3[Mn(CN)_6]$, and $[Cu(PPh_3)_3I]$.

$A$ metal complex of coordination number six having three different types of ligands $a$,$b$ and $c$ of composition $Ma_2b_2c_2$ can exist in several geometrical isomeric forms; the total number of such isomers is

Which one of the following species does not have a magnetic moment of $1.73 \ BM$ (spin only value)?

The two compounds pentaamminesulphatocobalt $(III)$ bromide and pentaamminesulphatocobalt $(III)$ chloride represent:

Which of the following is not correctly matched?