NEET2019ChemistryCoordination CompoundsActual
Correct increasing order for the wavelength of absorption in the visible region for the complexes of Co ³⁺ is
Options
- A[ Co ( CN )₆ ]³⁻, [ Co ( NH ₃ )₆ ]³⁺ , [ Co ( NH ₃ )₅ ( H ₂ O ) ]³⁺, [ Co ( NH ₃ )₅ Cl ]²⁺
- Baligned & [ Co ( CN )₆ ]³⁻, [ Co ( NH ₃ )₅ ( H ₂ O ) ]³⁺ & [ Co ( NH ₃ )₅ Cl ]²⁺, [ Co ( NH ₃ )₆ ]³⁺ aligned
- Caligned & [ Co ( NH ₃ )₆ ]³⁺, [ Co ( CN )₆ ]³⁻, & [ Co ( NH ₃ )₅ ( H ₂ O ) ]³⁺, [ Co ( NH ₃ )₅ Cl ]²⁺ aligned
- D[ Co ( NH ₃ )₅ Cl ]²⁺, [ Co ( NH ₃ )₅ ( H ₂ O ) ]³⁺ , [ Co ( NH ₃ )₆ ]³⁺, [ Co ( CN )₆ ]³⁻
Correct answer
A. [ Co ( CN )₆ ]³⁻, [ Co ( NH ₃ )₆ ]³⁺ , [ Co ( NH ₃ )₅ ( H ₂ O ) ]³⁺, [ Co ( NH ₃ )₅ Cl ]²⁺
Step-by-step solution
Strength of ligands attached with Co ³⁺ ion is in the order of CN ⁻> NH ₃> H ₂ O > Cl ⁻ . So, order of crystal field splitting energy (values of _o ) will be in the same order. Wavelength of absorbing light 1 _o