Question

If NO reacts with $\left[Cr\right(CO{)}_6]$, how many NO(s) are required to replace maximum number of CO groups?

• A. 4
• B. 6
• C. 2
• D. 5

Answer 1

The correct option is A 4

$CO$ is 2 electron donor and $NO$ is 3 electron donor so maximum 6 $CO$ replaced by $4NO$.
$Cr(CO{)}_6$
$6CO$ are present
number of $CO$ molecule $\times$ 2 = number of $NO$ molecule $\times$ 3
6 $\times$ 2= x $\times$ 3 (x = number of $NO$ molecule )
$x=4$