a) Using only the valence atomic orbitals of a hydrogenatom and a fluorine atom, and following the model ofFigure 9.46, how many MOs would you expect for the HFmolecule?

Verified step by step guidance

Identify the valence atomic orbitals of hydrogen and fluorine. Hydrogen has one 1s orbital, and fluorine has one 2s and three 2p orbitals.

Determine the number of molecular orbitals (MOs) formed. The number of MOs is equal to the number of atomic orbitals combined.

Combine the 1s orbital of hydrogen with the 2s and 2p orbitals of fluorine. This results in four atomic orbitals (1 from H and 3 from F).

Form molecular orbitals by combining these atomic orbitals. You will get bonding and antibonding MOs.

Count the total number of MOs formed. Since we started with four atomic orbitals, we will have four molecular orbitals.

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.

Molecular Orbitals (MOs)

Molecular orbitals are formed when atomic orbitals combine during the formation of a molecule. In the case of diatomic molecules like HF, the valence atomic orbitals of hydrogen and fluorine combine to create bonding and antibonding molecular orbitals. The number of MOs formed is equal to the sum of the atomic orbitals involved, which helps in understanding the electronic structure and stability of the molecule.

Valence Atomic Orbitals

Valence atomic orbitals are the outermost orbitals of an atom that participate in chemical bonding. For hydrogen, the valence orbital is the 1s orbital, while for fluorine, it includes the 2s and 2p orbitals. Understanding these orbitals is crucial for predicting how atoms will interact and bond to form molecules, such as HF.

Bonding and Antibonding Orbitals

In molecular orbital theory, bonding orbitals are lower in energy and stabilize the molecule, while antibonding orbitals are higher in energy and can destabilize it. When atomic orbitals combine, the resulting MOs include both types. For HF, the bonding orbital formed from the combination of hydrogen's 1s and fluorine's 2p orbitals will contribute to the molecule's stability, while any antibonding orbitals formed will have the opposite effect.

Recommended video:

Guided course

03:06

Molecular Orbital Theory

Related Practice

Textbook Question

Molecules that are brightly colored have a small energy gap between filled and empty electronic states (the HOMOLUMO gap; see Exercise 9.104). Suppose you have two samples, one is lycopene which is responsible for the red color in tomato, and the other is curcumin which is responsible for the yellow color in turmeric. Which one has the larger HOMO-LUMO gap?

Textbook Question

Azo dyes are organic dyes that are used for many applications, such as the coloring of fabrics. Many azo dyes are derivatives of the organic substance azobenzene, C12H10N2. A closely related substance is hydrazobenzene, C12H12N2. The Lewis structures of these two substances are

(Recall the shorthand notation used for benzene.) (b) How many unhybridized atomic orbitals are there on the N and the C atoms in each of the substances? How many unhybridized atomic orbitals are there on the N and the C atoms in hydrazobenzene?

Textbook Question

(Recall the shorthand notation used for benzene.) (c) Predict the N¬N¬C angles in each of the substances.

Textbook Question

(b) How many of the MOs from part (a) would be occupied by electrons?

Textbook Question

(c) It turns out that the difference in energies between the valence atomic orbitals of H and F are sufficiently different that we can neglect the interaction of the 1s orbital of hydrogen with the 2s orbital of fluorine.

The 1s orbital of hydrogen will mix only with one 2p orbital of fluorine. Draw pictures showing the proper orientation of all three 2p orbitals on F interacting with a 1s orbital on H. Which of the 2p orbitals can actually make a bond with a 1s orbital, assuming that the atoms lie on the z-axis?

Textbook Question

Carbon monoxide, CO, is isoelectronic to N2. (d) Would you expect the p2p MOs of CO to have equal atomic orbital contributions from the C and O atoms? If not, which atom would have the greater contribution?

views