Question

Which of the following species contain coordinate covalent bond :

• A. $AlC{l}_3$
• B. $CO$
• C. $\left[Fe\right(CN{)}_6{]}^{4-}$
• D. $N_3^{-}$

Answer 1

Answer: (B), (C), (D)

The correct options are
B $CO$
C $\left[Fe\right(CN{)}_6{]}^{4-}$
D $N_3^{-}$

$:C\equiv O:$ $\to$ In Carbonyl two covalent bonds are present and one coordinate bond is present from O$\to$C.

in $\left[Fe\right(N{)}_6{]}^{4-}\to$ All bonds are coordinate bond between ${CN}^{-}$ and ${Fe}^{+2}$ metal ion.

in $N_3^{-}$$\to [\stackrel{\cdot \cdot }{\underset{\cdot \cdot }{N}}=N=\stackrel{\cdot \cdot }{\underset{\cdot \cdot }{N}}{]}^{-}⟷[\ddot{N}\equiv N-\stackrel{\cdot \cdot }{\underset{\cdot \cdot }{N}}:{]}^{-}$

In $N_3^{-}$ covalent and coordinate both type of bonds are present.

in $Al{Cl}_3$$\to$ Icovalent bond is present only between $Al$ and $Cl$.