Ncert Exercises & Solutions

Q. 32 Arrange following complex ions in increasing order of crystal field splitting energy $(∆_{0})$ .

${[C r {(C l)}_{6}]}^{3 -}, {[C r {(C N)}_{6}]}^{3 -}, [C r (N H]$ ₃)63+.

CFSE is higher when the complex contains strong field ligand. Thus, crystal field spitting

energy increases in the order

${[C r {(C l)}_{6}]}^{3 -}, {[C r {(C N)}_{6}]}^{3 +}, {[C r {(N H_{3})}_{6}]}^{3 -}$

Because according to spectrochemical series the order of field strength is

$C l^{-} < N H_{3} < C N^{-}$