Textbook Question
The following models represent the structures of binary hydrides of second-row elements:
b. Draw an electron-dot structure for each hydride. For which hydride is there a problem in drawing the structure? Explain.
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Ch.22 - The Main Group Elements
McMurry8th EditionChemistryISBN: 9781292336145
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Table of contents
- Ch.1 - Chemical Tools: Experimentation & Measurement143
- Ch.2 - Atoms, Molecules & Ions134
- Ch.3 - Mass Relationships in Chemical Reactions149
- Ch.4 - Reactions in Aqueous Solution157
- Ch.5 - Periodicity & Electronic Structure of Atoms92
- Ch.6 - Ionic Compounds: Periodic Trends and Bonding Theory73
- Ch.7 - Covalent Bonding and Electron-Dot Structures47
- Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure51
- Ch.9 - Thermochemistry: Chemical Energy104
- Ch.10 - Gases: Their Properties & Behavior138
- Ch.11 - Liquids & Phase Changes43
- Ch.12 - Solids and Solid-State Materials56
- Ch.13 - Solutions & Their Properties98
- Ch.14 - Chemical Kinetics79
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Aqueous Equilibria: Acids & Bases94
- Ch.17 - Applications of Aqueous Equilibria125
- Ch.18 - Thermodynamics: Entropy, Free Energy & Equilibrium66
- Ch.19 - Electrochemistry130
- Ch.20 - Nuclear Chemistry73
- Ch.21 - Transition Elements and Coordination Chemistry122
- Ch.22 - The Main Group Elements155
- Ch.23 - Organic and Biological Chemistry43
Chapter 22, Problem 22.141a
a. Why is the SO3 molecule trigonal planar but the SO32– ion is trigonal pyramidal?
Verified step by step guidance1
Determine the number of valence electrons for each species: SO_3 and SO_3^{2-}.
For SO_3, sulfur (S) has 6 valence electrons and each oxygen (O) has 6 valence electrons, totaling 24 valence electrons.
For SO_3^{2-}, add 2 extra electrons to the total from SO_3 due to the 2- charge, resulting in 26 valence electrons.
Draw the Lewis structures for both SO_3 and SO_3^{2-}, ensuring to distribute electrons to satisfy the octet rule where possible.
Use VSEPR theory to determine the molecular geometry: SO_3 has no lone pairs on the central sulfur, resulting in a trigonal planar shape, while SO_3^{2-} has one lone pair on sulfur, leading to a trigonal pyramidal shape.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Molecular Geometry
Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is determined by the number of bonding pairs and lone pairs of electrons around the central atom, which influence the shape due to repulsion between electron pairs. Understanding molecular geometry is crucial for predicting the physical and chemical properties of substances.
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01:33
Molecular Geometry with Two Electron Groups
VSEPR Theory
Valence Shell Electron Pair Repulsion (VSEPR) theory is a model used to predict the geometry of individual molecules based on the repulsion between electron pairs in the valence shell of the central atom. According to VSEPR, electron pairs will arrange themselves to minimize repulsion, leading to specific molecular shapes, such as trigonal planar or trigonal pyramidal.
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02:13Molecular Shapes and VSEPR
Formal Charge and Ion Stability
Formal charge is a concept used to determine the distribution of electrons in a molecule or ion, helping to assess its stability. In the case of the SO3 molecule and the SO3^2– ion, the formal charge influences the arrangement of electrons and the resulting molecular shape. Understanding formal charge is essential for predicting the behavior of ions and their geometries.
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01:53Formal Charge
Related Practice
Textbook Question
Which compound in each of the following pairs is more ionic?
(b) P4O6 or Ga2O3
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Textbook Question
Consider the six second- and third-row elements in groups 4A–6A of the periodic table:
Possible structures for the binary fluorides of each of these elements in its highest oxidation state are shown below.
(a) Identify the nonfluorine atom in each case, and write the molecular formula of each fluoride.
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Textbook Question
Which compound in each of the following pairs is more covalent?
(a) PCl3 or AlF3
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Textbook Question
Select the group 4A element that best fits each of the following descriptions.
b. Is the least dense semimetal
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Textbook Question
Which element in each of the following pairs has more nonmetallic character?
(a) Se or Te
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