Which of the following ligands will cause the smallest crystal field splitting?

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

Which of the following comparisons is correct for the crystal field splitting energy $\Delta_0$ of the following complexes?
$I$- $[Co(H_2O)_6]^{2+}$
$II$- $[Co(H_2O)_6]^{3+}$
$III$- $[Fe(H_2O)_6]^{3+}$
$IV$- $[Fe(CN)_6]^{3+}$

The color of $[Ti(H_2O)_6]^{3+}$ is due to:

Arrange the following ligands in the order of increasing field strength:
$H_2O$ $(I)$,$CO$ $(II)$,$NH_3$ $(III)$,$I^{-}$ $(IV)$,$F^{-}$ $(V)$

Among the following complexes,the one which shows zero crystal field stabilization energy $(CFSE)$ is