Question

The correct order of the ligands, $OH ^{-}, NO _{3}^{-}, PPh _{3}$, pyridine, according to their increasing field strength is

• A. $NO _{3}^{-}< OH ^{-}<$ pyridine $< PPh _{3}$
• B. $OH ^{-}< NO _{3}^{-}< PPh _{3}<$ pyridine
• C. $OH ^{-}< NO _{3}^{-}<$ pyridine $< PPh _{3}$
• D. $NO _{3}^{-}< OH ^{-}< PPh _{3}<$ Pyridine

Answer 1

Answer: (A)

Increasing order of crystal field splitting power is as follows:
$\underset{\text{weak field ligand}}{NO^-_{3} < OH^-} < \underset{\text{strong field ligand}}{\text{pyridine} < PPh_3}$