According to crystal field theory, for which of the following coordination entities is $\Delta_o$ maximum?

Among the following $Cr(III)$ complexes,which one will have the highest octahedral crystal field splitting?

Complexes with $CN^{-}$ ligands are generally .......

The $3d$ metal ions form coloured compounds because the energy corresponding to the following lies in the visible range of the electromagnetic spectrum:

For which of the following types of ions is the number of unpaired electrons in octahedral complexes fixed at the same number as in the free ion,no matter how weak or strong the crystal field is?

Arrange the following complex ions in increasing order of crystal field splitting energy $(\Delta_{0}):$ $[Cr(Cl)_{6}]^{3-}, [Cr(CN)_{6}]^{3-}, [Cr(NH_{3})_{6}]^{3+}$