JEE Main 2019ChemistryChemical Bonding and Molecular StructureHardMCQ

JEE Main 2019 — Chemical Bonding and Molecular Structure Question with Solution

JEE Main 2019 (10 Jan Shift 1)

Question

Two pi and half sigma bonds are present in:

Choose an option

Show full solutionCorrect option: B
Correct answer
BN2+

Step-by-step explanation

O 2 − =σ1 s 2 < σ * 1 s 2 <σ2 s 2 < σ * 2 s 2 <σ2 p x 2 =π2 p y 2 =π2 p z 2 < π * 2 p y 2 = π * 2 p z 1

Bond Order = 6−3 2 =1.5

O 2 =σ1 s 2 < σ * 1 s 2 <σ2 s 2 < σ * 2 s 2 <σ2 p x 2 <π2 p y 2 =π2 p z 2 < π * 2 p y 1 = π * 2 p z 1

Bond order = 6−2 2 =2

N 2 =σ1 s 2 < σ * 1 s 2 <σ2 s 2 < σ * 2 s 2 <π2 p z 2 =π2 p z 2 <σ2 p x 2

Bond order = 6−0 2 =3

According to MOT ; electronic configuration of N2+ is:

N 2 + =σ1 s 2 < σ * 1 s 2 <σ2 s 2 < σ * 2 s 2 <π2 p x 2 =π2 p y 2 <σ2 p z 1

Bond order =129-4=2.5

i.e., 2π bonds and 0.5 σ bonds.

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About this question

This is a previous-year question from JEE Main 2019, covering the Chemical Bonding and Molecular Structure chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.