Pls answer this question..
Dear Student,
NO2 - has shortest N-O bond. It has one negative charge which makes two resonating structures. Both N-O bonds acquire partial double bond character. As one negative charge is making pi bonds alternatively between two N-O toms. We can say each N-O bond has 0.5 pi bond contribution between the atoms. In case of NO3- same charge is shared between three N-O bonds. Thus pi bond contribution is 0.33 for each bond. So N-O bond is shorter in NO2-. Rest two molecules have single bond between N and O. So they have even longer N-O bonds. So the correct answer is option b.
Regards
NO2 - has shortest N-O bond. It has one negative charge which makes two resonating structures. Both N-O bonds acquire partial double bond character. As one negative charge is making pi bonds alternatively between two N-O toms. We can say each N-O bond has 0.5 pi bond contribution between the atoms. In case of NO3- same charge is shared between three N-O bonds. Thus pi bond contribution is 0.33 for each bond. So N-O bond is shorter in NO2-. Rest two molecules have single bond between N and O. So they have even longer N-O bonds. So the correct answer is option b.
Regards