Question

Which complex of `Co^(2+)` will have the weakest crystal field splitting
A. `[Co(CN)_(6)]^(4-)`
B. `[CoCl_(6)]^(4-)`
C. `[Co(en)_(3)]^(2+)`
D. `[Co(H_(2)O)_(6)]^(2+)`

Answer 1

Correct Answer - B
Spectrochemical series
`I^(-) lt Br^(-) lt SCN^(-) lt Cl^(-) lt S^(2) lt F^(-)lt OH^(-) lt C_(2)O_(4)^(2-) lt H_(2)O lt NCS^(-) lt EDTA^(4-) lt NH_(3) lt en lt CN^(-) lt CO`
( Strongest)