Question:
An aqueous pink solution of cobalt(II) chloride changes to deep blue on the addition of an excess of HCl. This is because____________.
(i) [Co(H2O)6]2+ is transformed into [CoCl6]4–
(ii) [Co(H2O)6]2+ is transformed into [CoCl4]2–
(iii) tetrahedral complexes have smaller crystal field splitting than octahedral complexes.
(iv) tetrahedral complexes have larger crystal field splitting than octahedral complex.
Solution:
Option (ii) [Co(H2O)6]2+ is transformed into [CoCl4]2– and (iii) tetrahedral complexes have smaller crystal field splitting than octahedral complexes. are the answers.