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

Correct increasing order of spin magnetic moment $($in $B.M.)$ for the following complexes is:
$(I) \ [FeF_6]^{3-} \ (II) \ [V(H_2O)_6]^{2+} \ (III) \ [Fe(H_2O)_6]^{2+}$

Draw the structures of the geometrical isomers of $[Fe(NH_3)_2(CN)_4]^-$.

An aqueous solution of titanium chloride,when subjected to magnetic measurement,measured zero magnetic moment. Assuming the octahedral complex in aqueous solution,the formula of the complex is

Which type of isomerism is exhibited by the square planar complex shown in the image?

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 $[Cu(PPh_3)_3I]$.