The crystal field stabilization energy of $[Co(NH_3)_6]Cl_3$ is $......... \Delta_0$

Why are low spin tetrahedral complexes not formed?

State the limitations of crystal field theory $(CFT)$.

The hexaquo manganese $(II)$ ion contains five unpaired electrons,while the hexacyano manganese $(II)$ ion contains only one unpaired electron. Explain using Crystal Field Theory.

If $[Cu(H_{2}O)_{4}]^{2+}$ absorbs light of wavelength $600 \ nm$ for $d-d$ transition,then the value of octahedral crystal field splitting energy for $[Cu(H_{2}O)_{6}]^{2+}$ will be $..... \times 10^{-21} \ J$. (Nearest Integer)
(Given: $h = 6.63 \times 10^{-34} \ Js$ and $c = 3.08 \times 10^{8} \ ms^{-1}$)

Identify the correct decreasing order of wavelength of light absorbed for the following complex ions:
$I. [Co(H_2O)_6]^{3+}$
$II. [Co(CN)_6]^{3-}$
$III. [CoI_6]^{3-}$
$IV. [Co(en)_3]^{3+}$