Question

The ligand called p acid is

• A. $CO$
• B. $NH_3$
• C. $C _{2} O _{4}^{2-}$
• D. ethylene diamine

Answer 1

Answer: (A)

$CO$

Answer 2

Carbon monoxide is $\pi$ - acid ligand as it characterises both metal to carbon and carbon to metal bonding. The latter is known as $\pi$-acidic character.