Question 1

Which of the following is the correct electron configuration for the homonuclear diatomic molecule O$_2$ (including the 1s electrons)?

Accepted Answer

$1s^2 1s^{*2} 2s^2 2s^{*2} 2p_z^2 2p_x^2 2p_y^2 2p_x^{*1} 2p_y^{*1}$

Question 2

Based on the molecular orbital diagram for Be$_2$, what is the bond order and is the molecule expected to be paramagnetic or diamagnetic?

Accepted Answer

Bond order = 0; diamagnetic

Question 3

Which of the following is a valid resonance structure for CO$_2$?

Accepted Answer

$O=C=O$

Question 4

What is the steric number around the central atom in SF$_4$?

Accepted Answer

5

Question 5

Which type of hybrid orbitals are used by sulfur in SF$_4$?

Accepted Answer

$sp^3d$

Question 6

How many lone pairs are present on the central atom in the Lewis structure of SF$_4$?

Accepted Answer

1

Question 7

Which of the following best describes the electron geometry and molecular shape of SF$_4$?

Accepted Answer

Electron geometry: trigonal bipyramidal; Molecular shape: seesaw

Question 8

Which of the following statements about the molecular orbital diagram of O$_2$ is correct?

Accepted Answer

O$_2$ has two unpaired electrons in its $	ext{2p}^*$ antibonding orbitals, making it paramagnetic.

Question 9

What is the bond order of O$_2$ according to its molecular orbital diagram?

Accepted Answer

2

Question 10

Which process is necessary for the formation of $sp^2$ hybrid orbitals on carbon in CO$_3^{2-}$?

Accepted Answer

Promotion of an electron from the 2s to the 2p orbital, followed by hybridization of one 2s and two 2p orbitals.

Question 11

In the resonance structures of CO$_3^{2-}$, what is the formal charge on each oxygen atom?

Accepted Answer

Two oxygens have a formal charge of -1, one has 0.

Question 12

Which of the following best describes the bonding in CO$_3^{2-}$?

Accepted Answer

One double bond and two single bonds, with delocalized pi electrons.

Question 13

Which hybridization is expected for the central carbon atom in CO$_2$?

Accepted Answer

$sp$

Question 14

Which of the following best explains why Be$_2$ does not exist under normal conditions?

Accepted Answer

The bond order is zero, so there is no net bonding.

Question 15

Which of the following is true about the sigma and pi bonding in CO$_2$?

Accepted Answer

Each C=O bond consists of one sigma and one pi bond.

Question 16

Which of the following is a correct statement about the paramagnetism of O$_2$?

Accepted Answer

O$_2$ is paramagnetic because it has unpaired electrons in its molecular orbitals.

Question 17

Which of the following best describes the hybridization and geometry of the central atom in SF$_4$?

Accepted Answer

Hybridization: $sp^3d$; Geometry: seesaw

Question 18

Which of the following is a correct statement about the resonance in CO$_3^{2-}$?

Accepted Answer

The actual structure is an average of three resonance forms, with delocalized electrons.

Molecular Structure, Bonding, and Hybridization: Study Notes

Study Guide - Practice Questions