Crystal field splitting energy $(CFSE)$ for $[CoCl_6]^{4-}$ is $18000 \ cm^{-1}$. The crystal field splitting energy $(CFSE)$ for $[CoCl_4]^{2-}$ will be (in $cm^{-1}$)

$[Fe(H_2O)_6]^{3+}$ is strongly paramagnetic whereas $[Fe(CN)_6]^{3-}$ is weakly paramagnetic. Explain.

Which one of the following is a strong field ligand?

If the $CFSE$ of $[Ti(H_2O)_6]^{3+}$ is $-96.0 \ kJ / mol$,this complex will absorb maximum at wavelength $........nm$. (nearest integer)
Assume Planck's constant $(h) = 6.4 \times 10^{-34} \ Js$,Speed of light $(c) = 3.0 \times 10^8 \ m / s$ and Avogadro's constant $(N_A) = 6 \times 10^{23} / mol$.

$CuSO_4 \cdot 5 H_2O$ is blue in colour while $CuSO_4$ is colourless. Why?

The $d-$orbital electronic configuration of the complex among $[Co(en)_3]^{3+}$,$[CoF_6]^{3-}$,$[Mn(H_2O)_6]^{2+}$ and $[Zn(H_2O)_6]^{2+}$ that has the highest $CFSE$ is $:$