AP EAMCET202017 Sep 2020Morning ShiftChemistryCoordination CompoundsActual
The correct order for wavelengths of absorption in the visible region for the following complexes will be
Options
- A( [ Ni ( NH ₃ )₆ ]²⁺ < [ Ni ( H ₂ O )₆ ]²⁺ < [ Ni ( NO ₂ )₆ ]⁴⁻ )
- B( [ Ni ( NO ₂ )₆ ]⁴⁻ < [ Ni ( NH ₃ )₆ ]²⁺ < [ Ni ( H ₂ O )₆ ]²⁺ )
- C( [ Ni ( NH ₃ )₆ ]²⁺ < [ Ni ( NO ₂ )₆ ]⁴⁻ < [ Ni ( H ₂ O )₆ ]²⁺ )
- D( [ Ni ( NO ₂ )₆ ]⁴⁻ < [ Ni ( H ₂ O )₆ ]²⁺ < [ Ni ( NH ₃ )₆ ]²⁺ )
Correct answer
B. ( [ Ni ( NO ₂ )₆ ]⁴⁻ < [ Ni ( NH ₃ )₆ ]²⁺ < [ Ni ( H ₂ O )₆ ]²⁺ )
Step-by-step solution
Complexes, (I) ( [ Ni ( NH ₃ )₆ ]²⁺ ), (II) ( [ Ni ( H ₂ O )₆ ]²⁺ ) and (III) ( [ Ni ( NO ₂ )₆ ]⁴⁻ ) are made of ( Ni ²⁺ ) and ligands (- NH ₃,- H ₂ O ) and (- NO ₂⁻ )respectively. The field strength order of the ligands is ( H ₂ O < NH ₃ < NO ₂⁻ ) So, the order CFSE values: ( ₀^ II < ₀^ I < ₀^ III ) We know, (E= h c ) or (E 1 ) So, the order of wavelength of absorption in visible region will be, ( _ III < _ I < _ II )