Question

Which is the strongest field ligand?

• A. $N{O}_2^{-}$
• B. $C{N}^{-}$
• C. $N{H}_3$
• D. $en$

Answer 1

Answer: (B)

$C{N}^{-}$ is the strongest field ligand. Thus spectrochemical series order is:
$I^{-}<Br<C{l}^{-}<F^{-}<[C_2{O}_4{]}^{2-}<H_{2}O<py<N{H}_3<en<N{O}_2<C{N}^{-}<CO.$