Textbook Question
If hydrogen were used as a fuel, it could be burned according to this reaction: H2(g) + 1/2 O2(g) → H2O(g) Which fuel yields more energy per gram?
Ch.10 - Chemical Bonding I: The Lewis Model
Tro6th EditionChemistry: A Molecular ApproachISBN: 9780137832217
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Table of contents
- Ch.1 - Matter, Measurement & Problem Solving118
- Ch.2 - Atoms & Elements106
- Ch.3 - Molecules and Compounds131
- Ch.4 - Chemical Reactions and Chemical Quantities56
- Ch.5 - Introduction to Solutions and Aqueous Solutions82
- Ch.6 - Gases114
- Ch.7 - Thermochemistry96
- Ch.8 - The Quantum-Mechanical Model of the Atom60
- Ch.9 - Periodic Properties of the Elements90
- Ch.10 - Chemical Bonding I: The Lewis Model89
- Ch.11 - Chemical Bonding II: Molecular Shapes, VSEPR & MO Theory85
- Ch.12 - Liquids, Solids & Intermolecular Forces51
- Ch.13 - Solids & Modern Materials47
- Ch.14 - Solutions90
- Ch.15 - Chemical Kinetics115
- Ch.16 - Chemical Equilibrium68
- Ch.17 - Acids and Bases136
- Ch.18 - Aqueous Ionic Equilibrium153
- Ch.19 - Free Energy & Thermodynamics93
- Ch.20 - Electrochemistry106
- Ch.21 - Radioactivity & Nuclear Chemistry74
- Ch.22 - Organic Chemistry140
Chapter 10, Problem 113b
Draw the Lewis structure for each compound. b. H3PO3 (two OH bonds)
Verified step by step guidance1
Count the total number of valence electrons in the molecule. Phosphorus (P) has 5 valence electrons, each hydrogen (H) has 1, and each oxygen (O) has 6. Since there are three hydrogens and three oxygens, the total number of valence electrons is 5 (from P) + 3 (from H) + 18 (from O) = 26 valence electrons.
Place the least electronegative atom in the center, which is phosphorus in this case. Then, attach the oxygen and hydrogen atoms to the central phosphorus atom. Remember that two of the oxygens are bonded to hydrogen as OH groups.
Distribute the electrons around the atoms to complete the octets (or duet for hydrogen) while keeping in mind the total number of valence electrons. Each hydrogen will share two electrons, forming a single bond with oxygen. Each oxygen in the OH groups will form a single bond with hydrogen and a single bond with phosphorus.
Place any remaining electrons on the oxygen atoms to complete their octets. Oxygen typically needs 8 electrons to complete its octet, which includes shared and lone pairs.
Check the formal charges on each atom to ensure the most stable structure. The sum of the formal charges should equal the overall charge of the molecule, which is neutral in this case.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Lewis Structures
Lewis structures are diagrams that represent the bonding between atoms in a molecule and the lone pairs of electrons that may exist. They use dots to represent valence electrons and lines to represent bonds between atoms. Understanding how to draw Lewis structures is essential for visualizing molecular geometry and predicting the behavior of molecules in chemical reactions.
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04:28
Lewis Dot Structures: Ions
Valence Electrons
Valence electrons are the outermost electrons of an atom and are crucial in determining how an atom bonds with others. The number of valence electrons influences the atom's ability to form bonds, either by sharing electrons (covalent bonds) or transferring them (ionic bonds). For H3PO3, knowing the valence electrons of hydrogen, phosphorus, and oxygen is key to constructing its Lewis structure accurately.
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Molecular Geometry
Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. It is influenced by the number of bonds and lone pairs around the central atom, which can affect the molecule's reactivity and properties. In the case of H3PO3, understanding its geometry helps predict how it interacts with other molecules and its overall stability.
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Related Practice
Textbook Question
The azide ion, N3-, is a symmetrical ion, all of whose contributing resonance structures have formal charges. Draw three important contributing structures for this ion.
Textbook Question
Draw the Lewis structure for each compound. c. H3AsO4
Textbook Question
If hydrogen were used as a fuel, it could be burned according to this reaction: H2(g) + 1/2 O2(g) → H2O(g) Which fuel yields more energy per mole?
Textbook Question
If hydrogen were used as a fuel, it could be burned according to this reaction: H2(g) + 1/2 O2(g) → H2O(g) Use average bond energies to calculate ΔHrxn for the combustion of methane (CH4).
Textbook Question
List the following gas-phase ion pairs in order of the quantity of energy released when they form from separated gas-phase ions. List the pair that releases the least energy first. Na+ F-, Mg2+F-, Na+O2-, Mg2+O2-, Al3+O2-.