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

Question

An aqueous pink solution of Cobalt(II) chloride changes to deep blue on addition of excess of HCl. This is because :- (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) both (2) and (3)

Tardigrade Admin · Accepted Answer

Deep blue intense colour present in tetrahedral chloro complex. i.e. [ CoCl 4]2-

Q. An aqueous pink solution of Cobalt(II) chloride changes to deep blue on addition of excess of $H Cl$ . This is because :-

$[C o (H_{2} O)_{6}]^{2 +}$ is transformed into $[C o C l_{6}]^{4 -}$

$[C o (H_{2} O)_{6}]^{2 +}$ is transformed into $[C o C l_{4}]^{2 -}$

tetrahedral complexes have smaller crystal field splitting than octahedral complexes

both (2) and (3)

Deep blue intense colour present in tetrahedral chloro complex.
i.e. $[C o C l_{4}]^{2 -}$

Q. An aqueous pink solution of Cobalt(II) chloride changes to deep blue on addition of excess of HCl. This is because :-

[Co(H2​O)6​]2+ is transformed into [CoCl6​]4−

[Co(H2​O)6​]2+ is transformed into [CoCl4​]2−