Question
Chemistry Question on Molecular Orbital Theory
The correct order of C−O bond length among CO,CO32−, CO2 is
A
CO2<CO32−<CO
B
CO<CO32−<CO2
C
CO32−<CO2<CO
D
CO<CO2<CO32−
Answer
CO<CO2<CO32−
Explanation
Solution
A bond length is the average distance between the centres of nuclei of two bonded atoms.
A multiple bond (double or triple bonds) is always shorter than the corresponding single bond.
The C-atom in CO32− is sp2 hybridised as shown:
The C-atom in CO2 is sp hybridised with bond distance carbon-oxygen is 122pm.
O=C=O↔+O≡C−O−↔
\hspace37mm O−−C≡O+
The C-atom in CO is sp hybridised with C-O bond distance is 110 pm.
:C≡O+:
So, the correct order is
CO<CO2<CO32−