The magnetic moment for two complexes of empirical formula $Ni(NH_3)_4(NO_3)_2 \cdot 2H_2O$ is $0$ and $2.84 \ BM$ respectively. The second complex is not a neutral complex. The correct formula and geometry of the first complex is:

In which of the following complex ions is the value of the magnetic moment (spin only) $\sqrt{3} \ B.M.$ and outer $d-$orbitals are used in hybridization?

State the limitations of valence bond theory.

The number of isoelectronic species among $Sc^{3+}$, $Cr^{2+}$, $Mn^{3+}$, $Co^{3+}$, and $Fe^{3+}$ is $n$. If $n$ moles of $AgCl$ are formed during the reaction of the complex with the formula $CoCl_{3}(en)_{2}NH_{3}$ with excess $AgNO_{3}$, then the number of electrons present in the $t_{2g}$ orbital of the complex is . . . . . . .

$[Ni(PPh_3)_2Cl_2]$ is a paramagnetic complex. Identify the $INCORRECT$ statements about this complex.
$A$. The complex exhibits geometrical isomerism.
$B$. The complex is white in colour.
$C$. The calculated spin-only magnetic moment of the complex is $2.84 \ BM$.
$D$. The calculated $CFSE$ (Crystal Field Stabilization Energy) of $Ni$ in this complex is $-0.8 \Delta_0$.
$E$. The geometrical arrangement of ligands in this complex is similar to that in $Ni(CO)_4$.
Choose the correct answer from the options given below:

Total number of $e^-$ in $e_g$ orbitals of $Mn$ for the complex $[MnO_4]^-$ is: