Question

Which of the following complex has minimum magnitude of `Delta^(0)` ?
A. `|Cr(CN)_(6)|^(3-)`
B. `|Co(NH_(3))_(6)|^(3+)`
C. `|CoCl_(6)|^(3-)`
D. `|Cr(H_(2)O)_(6)|^(3+)`

Answer 1

Correct Answer - C
`|Cr(CH)_(6)|^(-3)Cr^(3+)=d^(3)=t_(2g)^(3) , CFSE = - 1.2Delta_(0)`
`|Co(NH_(3))_(6)|^(3+)(NH_(3)rarr "strong field ligand") Co^(3+) = d^(3)= t_(2g)^(6)e_(g)^(0) , CFSE = 2.4 Delta_(0)`
`|CoCl_(6)|^(3-)(Clrarr "weak field ligand")`
`Co^(3+) = d^(6) = t_(2g)^(4)e_(g)^(2) , CFSE = - o .4Delta_(0) |Cr(H_(2)O)_(6)|^(3+)`
`Cr^(3+) = d^(3) = t_(2g)^(3)e_(g)^(0) = - 1.2Delta_(0)`
`:.`"minimum" CFSE is for `|CoCl_(3)|^(3-)`