The degeneracy of $d-$orbitals is lost under:
$I$. Strong field ligand
$II$. Weak field ligand
$III$. Mixed field ligand
$IV$. Chelated ligand field
Choose the correct code:

The electronic configuration of the central atom of the complex $[MnO_4]^{2-}$ is:

Simplified absorption spectra of three complexes $(i), (ii)$ and $(iii)$ of $M^{n+}$ ion are provided below; their $\lambda_{max}$ values are marked as $A, B$ and $C$ respectively. The correct match between the complexes and their $\lambda_{max}$ values is
$(i)$ $[M(NCS)_6]^{(-6+n)}$
$(ii)$ $[MF_6]^{(-6+n)}$
$(iii)$ $[M(NH_3)_6]^{n+}$

The $CFSE$ for $[CoCl_6]^{4-}$ complex is $18000 \ cm^{-1}$. The $\Delta_t$ for $[CoCl_4]^{2-}$ will be ........... $cm^{-1}$.

Match the electronic configurations in List-$I$ with appropriate metal complex ions in List-$II$ and choose the correct option.
[Atomic Number: $Fe=26, Mn=25, Co=27$]

List-$I$	List-$II$
$P$. $t_{2g}^6 e_g^0$	$1$. $[Fe(H_2O)_6]^{2+}$
$Q$. $t_{2g}^3 e_g^2$	$2$. $[Mn(H_2O)_6]^{2+}$
$R$. $e^2 t_2^3$	$3$. $[Co(NH_3)_6]^{3+}$
$S$. $t_{2g}^4 e_g^2$	$4$. $[FeCl_4]^{-}$
	$5$. $[CoCl_4]^{2-}$

For which of the following pairs of complexes is the crystal field splitting energy $\Delta_0$ for $II > \Delta_0$ for $I$?

$I$	$II$
$(a). [Cr(H_2O)_6]^{2+}$	$[Cr(H_2O)_6]^{3+}$
$(b). [Fe(H_2O)_6]^{3+}$	$[Fe(CN)_6]^{3-}$
$(c). [Fe(CN)_6]^{3-}$	$[Ru(CN)_6]^{3-}$
$(d). [NiF_6]^{4-}$	$[NiF_6]^{2-}$