Question 1

Which statement best describes the main idea behind Valence Bond Theory (VBT)?

Accepted Answer

Atoms bond by overlapping their atomic orbitals, allowing electrons to be shared in localized regions between nuclei.

Question 2

Which of the following molecules is predicted to be paramagnetic according to Molecular Orbital Theory?

Accepted Answer

$\mathrm{O_2}$

Question 3

According to VSEPR theory, what is the molecular geometry of $\mathrm{SF_4}$?

Accepted Answer

Seesaw

Question 4

Which of the following best explains why $\mathrm{CO_2}$ is a nonpolar molecule despite having polar bonds?

Accepted Answer

The molecule is linear, and the bond dipoles are equal and opposite, cancelling each other.

Question 5

Which of the following statements about the HOMO-LUMO gap is correct?

Accepted Answer

It represents the energy difference between the highest occupied and lowest unoccupied molecular orbitals.

Question 6

Which of the following molecules has a bond order of 2 according to Molecular Orbital Theory?

Accepted Answer

$\mathrm{N_2}$

Question 7

A molecule has the following electron domain geometry: trigonal bipyramidal. If it has three bonding pairs and two lone pairs, what is its molecular shape?

Accepted Answer

T-shaped

Question 8

Which of the following is NOT a key assumption of VSEPR theory?

Accepted Answer

Bonding is explained by the overlap of atomic orbitals.

Question 9

Which of the following best describes the difference between sigma ($\sigma$) and pi ($\pi$) bonds?

Accepted Answer

$\sigma$ bonds result from end-to-end overlap, while $\pi$ bonds result from side-to-side overlap.

Question 10

Which molecule would you expect to have the largest bond dissociation energy based on bond order?

Accepted Answer

$\mathrm{N_2}$

Question 11

Using Molecular Orbital Theory, which molecule is predicted to be diamagnetic?

Accepted Answer

$\mathrm{N_2}$

Question 12

Which of the following is a consequence of the overlap of atomic orbitals in Valence Bond Theory?

Accepted Answer

Formation of localized bonds between atoms.

Question 13

Which of the following best explains why $\mathrm{H_2}$ does not absorb visible light?

Accepted Answer

Its HOMO-LUMO gap is too large for visible light absorption.

Question 14

Which of the following statements about molecular orbital diagrams is correct?

Accepted Answer

Bonding orbitals are lower in energy than antibonding orbitals.

Question 15

Which of the following molecules has a bond angle closest to $109.5^\circ$?

Accepted Answer

$\mathrm{CH_4}$

Question 16

A molecule has a central atom with two bonding pairs and two lone pairs. What is its molecular geometry?

Accepted Answer

Bent (angular)

Question 17

Which of the following is a key application of molecular orbital theory in solar energy conversion?

Accepted Answer

Understanding the HOMO-LUMO gap for efficient light absorption.

Question 18

Which of the following molecules has delocalized electrons according to molecular orbital theory?

Accepted Answer

$\mathrm{C_6H_6}$ (benzene)

Question 19

Which of the following best describes the effect of lone pairs on molecular geometry?

Accepted Answer

Lone pairs decrease bond angles due to increased repulsion.

Question 20

Which of the following is true regarding the bond order calculated from a molecular orbital diagram?

Accepted Answer

Bond order $= \dfrac{	ext{number of electrons in bonding orbitals} - 	ext{number of electrons in antibonding orbitals}}{2}$

Study Guide: Chemical Bonding II – Molecular Shapes, VSEPR, and Molecular Orbital Theory

Study Guide - Practice Questions

Study Guide - Flashcards