JEE Main · 2007 · 29 Apr 2007 · Offline · Chemical Bonding and Molecular Structure

In which of the following ionization processes, the bond order has increased and the magnetic behaviour has changed?

(A) $C_{2} ⟶ C_{2}^{+}$
(B) $NO ⟶ NO^{+}$ ✓ Correct
(C) $O_{2} ⟶ O_{2}^{+}$
(D) $N_{2} ⟶ N_{2}^{+}$

Answer: (B)

Solution

Removing an electron from

NO

to form

N O^{+}

takes it out of an antibonding

π^{*}

orbital, which raises the bond order from

2.5

3

. At the same time the single unpaired electron of paramagnetic

NO

is lost, so

N O^{+}

is diamagnetic, a real change in magnetic behaviour. The ionisation of nitric oxide is thus the one that both increases the bond order and alters the magnetism.

JEE Main · 2007 · 29 Apr 2007 · Offline · Single correct option

Practise more: all JEE Main PYQs on Chemical Bonding and Molecular Structure →

More JEE Main questions on Chemical Bonding and Molecular Structure

Given below are two statements:

Statement I: The number of species among $SF_{4}$ , $NH_{4}^{+}$ , $[NiCl_{4}]$ , $XeF_{4}$ , $[PtCl_{4}]^{2 -}$ , $SeF_{4}$ and $[Ni (CN)_{4}]^{2 -}$ , that have tetrahedral geometry …
JEE Main 2026View solution →
The formal changes on the atoms marked as (1) to (4) in the Lewis representation of $HnO_{3}$ molecule respectively are
JEE Main 2026View solution →
The correct increasing order of $C - H (A)$ , $C - O (B)$ , $C = O (C)$ and $C \equiv N (D)$ bonds in terms of covalent bond length is:
JEE Main 2026View solution →
Among $H_{2} S, H_{2} O, NF_{3}, NH_{3}$ and $CHCl_{3}$ , identify the molecule $(X)$ with lowest dipole moment value. The number of lone pairs of electrons present on the central atom of the molecule …
JEE Main 2026View solution →
Identify the molecule $(X)$ with maximum number of lone pairs of electrons (obtained using Lewis dot structure) among $HNO X_{3}$ , $H X_{2} SO X_{4}$ , $NF X_{3}$ and $O X_{3}$ . Choose the correct bond angle made by the central atom of the molecule (X).
JEE Main 2026View solution →
Given below are statements about some molecules/ions.

Identify the CORRECT statements.
A. The dipole moment value of $NF_{3}$ is higher than that of $NH_{3}$ .
B. The dipole moment value of $BeH_{2}$ is zero.
C. The bond order of …
JEE Main 2026View solution →