An aqueous pink solution of cobalt (II) chloride changes to deep blue on addition of excess of `HCl`. This is because ....... .

Options

A. `[Co(H_(2)O)_(6)]^(2+)` is transformed into `[CoCl_(6)]^(4-)`
B. `[Co(H_(2)O)_(6)]^(2+)` is transformed into `[CoCl_(4)]^(2+)`
C. `tetrahedral complexes have smaller crystal field splitting than octahedral complexes.
D. tetrahedral complexes have larger crystal field splitting than octahedral complex.

Answer

B, C

Explanation

b,c are both correct options.