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Ch.9 - Molecular Geometry and Bonding Theories
Brown - Chemistry: The Central Science 15th Edition
Brown15th EditionChemistry: The Central ScienceISBN: 9780137542970Not the one you use?Change textbook
All textbooksBrown 15th EditionCh.9 - Molecular Geometry and Bonding TheoriesProblem 23
Chapter 9, Problem 23

Give the electron-domain and molecular geometries of a molecule that has the following electron domains on its central atom: (a) four bonding domains and no nonbonding domains (b) three bonding domains and two nonbonding domains (c) five bonding domains and one nonbonding domain (d) four bonding domains and two nonbonding domains.

Verified step by step guidance
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Step 1: Understand the concept of electron-domain geometry and molecular geometry. Electron-domain geometry considers all electron domains (bonding and nonbonding) around the central atom, while molecular geometry considers only the arrangement of bonded atoms.
Step 2: For (a), identify the electron-domain geometry for a central atom with four bonding domains and no nonbonding domains. Use VSEPR theory to determine the shape.
Step 3: For (b), identify the electron-domain geometry for a central atom with three bonding domains and two nonbonding domains. Use VSEPR theory to determine the shape and consider how nonbonding domains affect the molecular geometry.
Step 4: For (c), identify the electron-domain geometry for a central atom with five bonding domains and one nonbonding domain. Use VSEPR theory to determine the shape and consider the effect of the nonbonding domain on the molecular geometry.
Step 5: For (d), identify the electron-domain geometry for a central atom with four bonding domains and two nonbonding domains. Use VSEPR theory to determine the shape and consider how the two nonbonding domains affect the molecular geometry.

Key Concepts

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

Electron-Domain Geometry

Electron-domain geometry refers to the spatial arrangement of all electron domains (bonding and nonbonding) around a central atom in a molecule. It is determined by the number of electron domains, which can include single bonds, double bonds, triple bonds, and lone pairs. The geometry helps predict the overall shape of the molecule based on the repulsion between these electron domains.
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Electron Geometry

Molecular Geometry

Molecular geometry describes the three-dimensional arrangement of the atoms in a molecule, considering only the positions of the nuclei of the atoms. It is influenced by the electron-domain geometry but focuses solely on the bonding pairs of electrons. Different arrangements of bonding pairs lead to distinct molecular shapes, such as tetrahedral, trigonal planar, or octahedral.
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VSEPR Theory

Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of molecules based on the repulsion between electron pairs surrounding a central atom. According to VSEPR, electron pairs will arrange themselves to minimize repulsion, leading to specific geometries. This theory is essential for determining both electron-domain and molecular geometries based on the number of bonding and nonbonding domains.
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Related Practice
Textbook Question

In which of the following molecules can you confidently predict the bond angles about the central atom, and for which would you be a bit uncertain? Explain in each case. (a) H2S, (b) BCl3, (c) CH3I, (d) CBr4, (e) TeBr4.

Textbook Question

Give the electron-domain and molecular geometries for the following molecules and ions: c. SF4

Textbook Question

Would you expect the nonbonding electron-pair domain in NH3 to be greater or less in size than the corresponding one in PH3?

Textbook Question

Give the electron-domain and molecular geometries for the following molecules and ions: a. HCN