Textbook Question
a. How many alkenes could you treat with H2, Pd/C to prepare methylcyclopentane?
b. Which of the alkenes is the most stable?
c. Which of the alkenes has the smallest heat of hydrogenation?
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Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
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Table of contents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 1)31
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding (Part 2)65
- Ch. 2 - Acids and Bases: Central to Understanding Organic Chemistry84
- Ch. 3 - An Introduction to Organic Compounds:Nomenclature, Physical Properties, and Structure183
- Ch. 4 - Isomers: The Arrangement of Atoms in Space121
- Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics83
- Ch. 6 - The Reactions of Alkenes • The Stereochemistry of Addition Reactions175
- Ch. 7 - The Reactions of Alkynes • An Introduction to Multistep Synthesis119
- Ch. 8 - Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene148
- Ch. 9 - Substitution and Elimination Reactions of Alkyl Halides212
- Ch. 10 - Reactions of Alcohols, Ethers, Epoxides, Amines, and Sulfur-Containing Compounds131
- Ch. 11 - Organometallic Compounds60
- Ch. 12 - Radicals90
- Ch. 13 - Mass Spectrometry; Infrared Spectroscopy; UV/Vis Spectroscopy62
- Ch. 14 - NMR Spectroscopy95
- Ch. 15 - Reactions of Carboxylic Acids and Carboxylic Acid Derivatives123
- Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives141
- Ch. 17 - Reactions at the Alpha-Carbon101
- Ch. 18 - Reactions of Benzene and Substituted Benzenes144
- Ch. 19 - More About Amines • Reactions of Heterocyclic Compounds49
- Ch. 20 - The Organic Chemistry of Carbohydrates80
- Ch. 21 - Amino Acids, Peptides, and Proteins57
- Ch. 22 - Catalysis in Organic Reactions and in Enzymatic Reactions35
- Ch. 23 - The Organic Chemistry of the Coenzymes—Compounds Derived from Vitamins1
- Ch. 28 - Pericyclic Reactions58
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Bruice 8th EditionCh. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and KineticsProblem 59
Bruice 8th EditionCh. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and KineticsProblem 59Chapter 6, Problem 59
a. Which of the following reactions has the larger ∆S° value?
b. Is the ∆S° value positive or negative?
Verified step by step guidance1
Step 1: Understand the concept of entropy (∆S°). Entropy is a measure of disorder or randomness in a system. A positive ∆S° indicates an increase in disorder, while a negative ∆S° indicates a decrease in disorder.
Step 2: Analyze the reactions provided (if any). Compare the number of reactant molecules to the number of product molecules. Reactions that produce more molecules or transition from a solid/liquid to a gas generally have a larger positive ∆S° value.
Step 3: Consider the physical states of the reactants and products. For example, gas formation increases entropy significantly compared to liquids or solids.
Step 4: Evaluate whether the ∆S° value is positive or negative based on the changes in molecular complexity, physical states, and the number of molecules involved in the reaction.
Step 5: If no specific reactions are provided, note that the larger ∆S° value typically corresponds to reactions with greater increases in disorder, such as decomposition reactions or reactions producing gases.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Entropy (∆S°)
Entropy, denoted as ∆S°, is a measure of the disorder or randomness in a system. In chemical reactions, a positive ∆S° indicates an increase in disorder, often associated with the formation of gases or the breaking of bonds, while a negative ∆S° suggests a decrease in disorder. Understanding how molecular arrangements change during reactions is crucial for predicting the sign and magnitude of ∆S°.
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Explaining what entropy is.
Factors Affecting Entropy
Several factors influence the entropy change in a reaction, including the states of matter (solid, liquid, gas), the number of moles of reactants and products, and temperature. Generally, reactions that produce more gas molecules than they consume will have a positive ∆S°, while those that result in fewer gas molecules will have a negative ∆S°. Recognizing these factors helps in comparing different reactions.
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Thermodynamic Spontaneity
The spontaneity of a reaction is determined by the Gibbs free energy change (∆G), which incorporates both enthalpy (∆H) and entropy (∆S°) changes. A reaction is spontaneous at constant temperature and pressure if ∆G is negative, which can occur when ∆S° is positive and/or when the enthalpy change is favorable. Understanding this relationship is essential for predicting the direction of chemical reactions.
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Related Practice
Textbook Question
Draw the structure of a compound with molecular C8H14 that reacts with one equivalent of H2 over Pd/C to form a meso compound
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Textbook Question
Draw structures for the following:
c. (3Z,5Z)-4,5-dimethyl-3,5-nonadiene
d. (3E,5E)-2,5-dibromo-3,5-octadiene
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Textbook Question
Given the reaction coordinate diagram for the reaction of A to form G, answer the following questions:
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a. How many intermediates are formed in the reaction?
b. Which letters represent transition states?
c. What is the fastest step in the reaction?
d. Which is more stable: A or G?
e. Does A or E form faster from C?
f. Which is the more stable intermediate?
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Textbook Question
Using curved arrows, show the mechanism of the following reaction:
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Textbook Question
a. What is the equilibrium constant for a reaction that is carried out at 25 °C (298 K) with ∆H° = 20 kcal/mol and ∆S° = 5.0 × 10-2 kcal mol-1 K-1?
b. What is the equilibrium constant for the same reaction carried out at 125 °C?
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