Arrange following complex ions in increasing order of crystal field splitting energy `(Delta_(0))`.

Explanation

CFSE is higher when the complex contains strong field ligand. Thus, crystal field splitting energy increases in the order
`[Cr(Cl)_(6)]^(3-) lt [Cr(NH_(3))_(6)]^(3+) lt [Cr(CN)_(6)]^(3-)`.
Because according to spectrochemical series the order of field strength is
`Cl^(-) lt NH_(3) lt CN^(-)`