Question

Bond length of C - O is minimum in
(A) $CO$
(B) \[C{O_2}\]
(C) $C{O_3}^{ - 2}$
(D) $HCO{O^ - }$

Answer 1

Hint:The bond is the connection between two atoms. The bond length is minimum or maximum according to their attraction power. To find the bond length between two atoms, we need to use bond order and resonating structure.

Complete step by step answer:
Firstly we discuss bond length.
Bond Length-The distance between atoms is known as bond length.
The main point is that the atoms have a strong bond and have minimum bond length. While those atoms have maximum bond length they are weak in nature.
Resonance structure-In chemistry, a single compound is described by a much different structure is known as resonance structure.
Here, we will find the minimum bond length of \[C\, - \, O\] among the given options. The main point is maximum bond length has a minimum bond order.
So, find the bond order
Bond Order$ = \dfrac{{total\,number\,of\,bond\,in\,all\,respected\,structure\,between\,two\,atom}}{{total\,number\,of\,resonance\,structure}} \\
  \, \\
\ $
Another formula is
Bond Order =$\dfrac{{(number{\text{ }}of{\text{ }}bonding{\text{ }}electrons - number{\text{ }}of{\text{ }}antibonding{\text{ }}electrons)}}{2}$
The bond order of carbon monoxide is $3$. Because isoelectronic has the same bond order according to molecular orbital theory. We know that the total electron of ${N_2}$ and $CO$ is $14$.
$6$ - carbon
$8$ - oxygen
$C{O_2}$ bond order is $2$, due to a double bond.
$O = C = O$
Bond order of $C{O_3}^{ - 2}$ is
\[\mathop O\limits_{\mathop {||}\limits_{{}_{{}_{\mathop /\limits_{{{^O}^ - }} }}{C_{_{_{{\backslash _O}}}}}} } \] \[\mathop {{O^ - }}\limits_{\mathop |\limits_{{}_{{}_{\mathop {//}\limits_{{{^O}^{}}} }}{C_{_{_{{\backslash _{{O^ - }}}}}}}} } \] \[\mathop {{O^ - }}\limits_{\mathop {||}\limits_{{}_{{}_{\mathop /\limits_{{{^O}^ - }} }}{C_{_{_{\backslash {\backslash _O}}}}}} } \]

According to formula B.O = $\dfrac{4}{3}$ = $1.33$
bond order of $HCO{O^ - }$
\[\mathop {\,\,\,O}\limits_{\mathop {\,\,\,||}\limits_{\,\,\,H - C - {O^ - }} } \,\,\,\,\] $ \to $ \[\mathop {\,\,\,\,{O^ - }}\limits_{\mathop {\,\,\,|}\limits_{\,\,\,H - C = O} } \,\,\,\,\]

B.O$ = \dfrac{3}{2}$ $ = 1.5$

$CO$ has maximum bond order so, that's why it has a minimum bond length.

Here, option A is the correct answer.

Note:
The bond length is measured in the picometer. Bonds have three kinds among them: single stronger than a double and third bond. Isoelectronic elements have the same number of electrons. If elements have the same number of valence electrons and structure, they are also called isoelectronic. Valence electrons are the outermost electrons that are also responsible to form a bond between atoms.