(i) In [Ti (H2O)6 ]2+ , the central metal ion is Ti3+ which has d1 configuration. This single electron occupies one of the ttg orbitals in the octahedral aqua ligand field.
(ii) When white light falls on this complex, the d electron absorbs light and promotes itself to eg level.
(iii) The spectral data show the absorption maximum is at 20000 cm-1 corresponding to the crystal field splitting energy (∆0 ) 239.7 kJ mol-1 . The transmitted colour associated with this absorption is purple and hence the complex appears in purple in colour.