Textbook Question
The following compounds can all react as bases.
a. For each compound, show its conjugate acid. Show any resonance forms if applicable.
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Ch. 2 - Acids and Bases; Functional Groups
Wade9th EditionOrganic ChemistryISBN: 9780135213728
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Table of contents
- Ch.1 - Structure and Bonding107
- Ch. 2 - Acids and Bases; Functional Groups115
- Ch.3 - Structure and Stereochemistry of Alkanes100
- Ch.4 - The Study of Chemical Reactions99
- Ch.5 - Stereochemistry93
- Ch.6 - Alkyl Halides; Nucleophilic Substitution118
- Ch. 7 - Structure and Synthesis of Alkenes; Elimination158
- Ch.8 - Reactions of Alkenes171
- Ch.9 - Alkynes91
- Ch.10 - Structure and Synthesis of Alcohols143
- Ch.11 - Reactions of Alcohols104
- Ch. 12 - Infrared Spectroscopy and Mass Spectrometry22
- Ch. 13 - Nuclear Magnetic Resonance Spectroscopy45
- Ch. 14 - Ethers, Epoxides, and Thioethers72
- Ch. 15 - Conjugated Systems, Orbital Symmetry, and Ultraviolet Spectroscopy89
- Ch. 16 - Aromatic Compounds74
- Ch. 17 - Reactions of Aromatic Compounds126
- Ch. 18 - Ketones and Aldehydes193
- Ch. 19 - Amines129
- Ch. 20 - Carboxylic Acids77
- Ch. 21 - Carboxylic Acid Derivatives141
- Ch. 22 - Condensations and Alpha Substitutions of Carbonyl Compounds175
- Ch. 23 - Carbohydrates and Nucleic Acids93
- Ch. 24 - Amino Acids, Peptides, and Proteins54
Chapter 2, Problem 45a
The following compounds can all react as acids.
a. For each compound, show its conjugate base. Show any resonance forms if applicable. b. Rank the conjugate bases in the order you would predict, from most stable to least stable.
Verified step by step guidance1
Identify the acidic hydrogen in each compound. For carboxylic acids like CH3COOH, CF3COOH, and CF3CH2COOH, the acidic hydrogen is the one attached to the oxygen in the -COOH group. For alcohols like CH3CH2OH, the acidic hydrogen is the one attached to the oxygen in the -OH group.
Remove the acidic hydrogen from each compound to form the conjugate base. For example, removing the hydrogen from CH3COOH results in CH3COO⁻.
Draw any resonance structures for the conjugate bases. For carboxylate ions like CH3COO⁻, resonance can be shown by delocalizing the negative charge between the two oxygen atoms.
Consider the stability of each conjugate base. Factors affecting stability include resonance, electronegativity, and inductive effects. For instance, the presence of electronegative atoms like fluorine in CF3COO⁻ can stabilize the conjugate base through inductive effects.
Rank the conjugate bases from most stable to least stable based on the factors discussed. Generally, more resonance and greater electronegativity lead to more stable conjugate bases.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Conjugate Bases
A conjugate base is the species that remains after an acid donates a proton (H+). Understanding how to derive the conjugate base from an acid is crucial for predicting acid-base reactions. For example, when acetic acid (CH3COOH) donates a proton, it forms its conjugate base, acetate (CH3COO-). The stability of the conjugate base significantly influences the strength of the corresponding acid.
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03:27
Conjugated states
Resonance Structures
Resonance structures are different ways of drawing the same molecule that illustrate the delocalization of electrons. In the context of conjugate bases, resonance can stabilize the negative charge by spreading it over multiple atoms. For instance, the acetate ion has resonance forms that contribute to its stability, making it a more favorable conjugate base compared to others without such delocalization.
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03:04Drawing Resonance Structures
Acid Strength and Stability of Conjugate Bases
The strength of an acid is inversely related to the stability of its conjugate base; a more stable conjugate base corresponds to a stronger acid. Factors affecting stability include electronegativity, resonance, and inductive effects. For example, a conjugate base with a highly electronegative atom can stabilize a negative charge better, leading to a stronger acid. Ranking the stability of conjugate bases helps predict the relative strengths of the corresponding acids.
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04:31Stability of Conjugated Intermediates
Related Practice
Textbook Question
Predict the products of the following acid–base reactions.
(h)
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Textbook Question
Compare the relative acidity of 1-molar aqueous solutions of the following acids.
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Textbook Question
Consider the following proposed Brønsted–Lowry acid–base reactions. In each case, draw the products of a transfer of the most acidic proton on the acid to the most basic site on the base. Use Appendix 4 to find or estimate the pKa values for the acids and the pKb values for the bases. Then determine which side of the reaction is favored, either reactants or products.
(a)
(b)
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Textbook Question
The following compounds can all react as bases.
b. Rank the conjugate acids in the order you would predict, from most stable to least stable.
2
views
Textbook Question
The following compounds can all react as acids.
c. Rank the original compounds in order, from strongest acid to weakest acid.