Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure

McMurry8th EditionChemistryISBN: 9781292336145Not the one you use?Change textbook

McMurry 8th Edition

Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure

Problem 107c

Chapter 8, Problem 107c

Carbon monoxide is produced by incomplete combustion of fossil fuels. (c) What is the bond order of CO? Does this match the bond order predicted by the electron-dot structure?

Verified step by step guidance

Step 1: To determine the bond order of a molecule, we need to know the molecular orbital diagram of the molecule. For CO, the molecular orbital diagram shows that there are 10 electrons in bonding orbitals and 2 electrons in antibonding orbitals.

Step 2: The bond order is calculated as the difference between the number of electrons in bonding and antibonding orbitals, divided by 2. So, for CO, the bond order is (10-2)/2 = 4.

Step 3: The electron-dot structure, also known as the Lewis structure, for CO shows a triple bond between the carbon and oxygen atoms. This suggests a bond order of 3.

Step 4: The discrepancy between the bond order calculated from the molecular orbital diagram (4) and the bond order predicted by the electron-dot structure (3) is due to the fact that the electron-dot structure does not take into account the presence of antibonding electrons.

Step 5: Therefore, while the electron-dot structure provides a useful approximation, the molecular orbital theory provides a more accurate description of the bonding in CO.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Bond Order

Bond order is a measure of the number of chemical bonds between a pair of atoms. It is calculated as the difference between the number of bonding electrons and the number of antibonding electrons, divided by two. In the case of carbon monoxide (CO), the bond order can be determined from its molecular orbital configuration, indicating the strength and stability of the bond.

Molecular Orbital Theory

Molecular Orbital Theory describes the behavior of electrons in molecules, where atomic orbitals combine to form molecular orbitals that can be occupied by electrons. For CO, the molecular orbital diagram shows that the bond order is 3, indicating a triple bond between carbon and oxygen. This theory provides a more accurate representation of bonding compared to simple Lewis structures.

Electron-Dot Structure (Lewis Structure)

The electron-dot structure, or Lewis structure, represents the valence electrons of atoms within a molecule. For CO, the Lewis structure suggests a double bond between carbon and oxygen, which may not accurately reflect the actual bond order. This discrepancy highlights the limitations of Lewis structures in predicting molecular properties compared to molecular orbital theory.

Recommended video:

Guided course

04:28

Lewis Dot Structures: Ions

Related Practice

Textbook Question

At high temperatures, sulfur vapor is predominantly in the form of S₂(g) molecules. (a) Assuming that the molecular orbitals for third-row diatomic molecules are analogous to those for second-row molecules, construct an MO diagram for the valence orbitals of S₂(g).

466

views

Textbook Question

Cyclooctatetraene dianion, C₈H₈^2-, is an organic ion with the structure shown. Considering only the p bonds and not the s bonds, cyclooctatetraene dianion can be described by the following energy diagrams of its p molecular orbitals:

(a) What is the hybridization of the 8 carbon atoms?

1074

views

Textbook Question

Carbon monoxide is produced by incomplete combustion of fossil fuels. (a) Give the electron configuration for the valence molecular orbitals of CO. The orbitals have the same energy order as those of the N2 molecule.

346

views

Textbook Question

The dichromate ion, Cr2O72-, has neither Cr¬Cr nor O¬O bonds. (b) How many outer-shell electrons does each Cr atom have in your electron-dot structure? What is the likely geometry around the Cr atoms?

In the cyanate ion, OCN-, carbon is the central atom.(d) Which hybrid orbitals are used by the C atom, and how many p bonds does the C atom form?

1005

views

Textbook Question

Carbon monoxide is produced by incomplete combustion of fossil fuels. (b) Do you expect CO to be paramagnetic or diamagnetic?

393

views