Ch. 3 - Acids and BasesWorksheetSee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Solution: Consider the following reaction given below. One of the 5 resonance structures (Lewis structures) that contribute to the resonance hybrid of the conjugate base of phenol is represented (below) as one of the products in the given chemical equation. (a) Draw the additional 4 different resonance structures (Lewis structures) that contribute to the resonance hybrid of the conjugate base of toluene. For each of the four Lewis structures (resonance structures) that you give, you must show all atoms, all bonding valence electrons, all unshared valence electrons, and each nonzero formal charge. (b) Clearly give the numerical value (in degrees) for the HCH bond angle in the conjugate base of toluene. (c) The equilibrium shown below lies to the left. This, of course, means that phenol is more acidic than toluene. Using structural considerations, provide a clear, concise explanation (but in as much detail as possible) why this equilibrium lies to the left. NOTE that a correct answer to this part is not that “the pKa of phenol is less than the pKa of toluene” because this is merely a restatement of the fact that phenol is more acidic than toluene. 

Solution: Consider the following reaction given below. One of the 5 resonance structures (Lewis structures) that contribute to the resonance hybrid of the conjugate base of phenol is represented (below) as one

Problem

Consider the following reaction given below. One of the 5 resonance structures (Lewis structures) that contribute to the resonance hybrid of the conjugate base of phenol is represented (below) as one of the products in the given chemical equation. (a) Draw the additional 4 different resonance structures (Lewis structures) that contribute to the resonance hybrid of the conjugate base of toluene. For each of the four Lewis structures (resonance structures) that you give, you must show all atoms, all bonding valence electrons, all unshared valence electrons, and each nonzero formal charge. (b) Clearly give the numerical value (in degrees) for the HCH bond angle in the conjugate base of toluene. (c) The equilibrium shown below lies to the left. This, of course, means that phenol is more acidic than toluene. Using structural considerations, provide a clear, concise explanation (but in as much detail as possible) why this equilibrium lies to the left. NOTE that a correct answer to this part is not that “the pKa of phenol is less than the pKa of toluene” because this is merely a restatement of the fact that phenol is more acidic than toluene.