Textbook Question
Four different structures (a), (b), (c), and (d) can be drawn for compounds named dibromobenzene, but only three different compounds actually exist. Explain.(a) (b) (c) (d)
472
views
Ch.7 - Covalent Bonding and Electron-Dot Structures
McMurry8th EditionChemistryISBN: 9781292336145
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 - Chemical Tools: Experimentation & Measurement170
- Ch.2 - Atoms, Molecules & Ions160
- Ch.3 - Mass Relationships in Chemical Reactions169
- Ch.4 - Reactions in Aqueous Solution199
- Ch.5 - Periodicity & Electronic Structure of Atoms102
- Ch.6 - Ionic Compounds: Periodic Trends and Bonding Theory92
- Ch.7 - Covalent Bonding and Electron-Dot Structures61
- Ch.8 - Covalent Compounds: Bonding Theories and Molecular Structure59
- Ch.9 - Thermochemistry: Chemical Energy122
- Ch.10 - Gases: Their Properties & Behavior155
- Ch.11 - Liquids & Phase Changes54
- Ch.12 - Solids and Solid-State Materials73
- Ch.13 - Solutions & Their Properties120
- Ch.14 - Chemical Kinetics98
- Ch.15 - Chemical Equilibrium125
- Ch.16 - Aqueous Equilibria: Acids & Bases110
- Ch.17 - Applications of Aqueous Equilibria147
- Ch.18 - Thermodynamics: Entropy, Free Energy & Equilibrium86
- Ch.19 - Electrochemistry154
- Ch.20 - Nuclear Chemistry96
- Ch.21 - Transition Elements and Coordination Chemistry156
- Ch.22 - The Main Group Elements187
- Ch.23 - Organic and Biological Chemistry51
Chapter 7, Problem 102
Draw the resonance structure indicated by the curved arrows. Assign formal charges, and evaluate which of the two structures is a larger contributor to the resonance hybrid.
Verified step by step guidance1
Identify the movement of electrons as indicated by the curved arrows. The first arrow shows the movement of a lone pair from the oxygen to form a double bond with the carbon. The second arrow shows the movement of the double bond between carbon and nitrogen to form a lone pair on nitrogen.
Draw the new resonance structure based on the electron movement. The oxygen now has a single bond with carbon and a positive formal charge, while the nitrogen has a lone pair and a negative formal charge.
Assign formal charges to each atom in the new resonance structure. Oxygen will have a +1 formal charge, and nitrogen will have a -1 formal charge.
Compare the stability of the two resonance structures. Consider factors such as the placement of formal charges and the electronegativity of the atoms involved.
Evaluate which resonance structure is the larger contributor to the resonance hybrid. The structure with the formal charges on the more electronegative atoms and fewer formal charges overall is typically the larger contributor.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
4mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Resonance Structures
Resonance structures are different Lewis structures for the same molecule that depict the same arrangement of atoms but differ in the distribution of electrons. These structures are used to represent delocalized electrons within certain molecules, indicating that the actual structure is a hybrid of these forms. Understanding resonance is crucial for predicting the stability and reactivity of molecules.
Recommended video:
Guided course
01:42
Resonance Structures
Formal Charge
Formal charge is a theoretical charge assigned to an atom in a molecule, calculated by comparing the number of valence electrons in the free atom to the number of electrons assigned to it in the Lewis structure. It helps in determining the most stable resonance structure, as the structure with the lowest formal charges on atoms is generally more favorable. Assigning formal charges correctly is essential for evaluating the contribution of each resonance structure.
Recommended video:
Guided course
01:53Formal Charge
Resonance Hybrid
The resonance hybrid is the actual structure of a molecule that is a weighted average of all its resonance structures. It reflects the delocalization of electrons across the molecule, leading to increased stability. The contribution of each resonance structure to the hybrid is determined by factors such as formal charge, electronegativity, and overall stability, making it important to evaluate which structure is the most significant contributor.
Recommended video:
Guided course
00:51Hybridization
Related Practice
Textbook Question
Use the following information plus the data given in Tables 6.2 and 6.3 to calculate the second electron affinity, Eea2, of oxygen. Is the O2-ion stable in the gas phase? Why is it stable in solid MgO?Heat of sublimation for Mg1s2 = +147.7 kJ/mol Bond dissociation energy for O21g2 = +498.4 kJ/mol Eea1 for O1g2 = -141.0 kJ/mol Net energy change for formation of MgO(s) from its elements = -601.7 kJ/mol
489
views
Textbook Question
Assign formal charges to the atoms in the following structures. Which of the two do you think is the more important contributor to the resonance hybrid?(a)(b)
459
views
Textbook Question
Propose structures for molecules that meet the following descriptions. (b) Contains an N atom that has one p bond and two s bonds
506
views
Textbook Question
In the cyanate ion, OCN-, carbon is the central atom.(b) Which resonance structure makes the greatest contributionto the resonance hybrid? Which makes the leastcontribution? Explain.
1336
views
Textbook Question
The dichromate ion, Cr2O72-, has neither Cr¬Cr nor O¬O bonds. (a) Taking both 4s and 3d electrons into account, draw an electron-dot structure that minimizes the formal charges on the atoms.
982
views