Domanda del libro di testo
Calculate the percentage of isopropylcyclohexane molecules that have the isopropyl substituent in an equatorial position at equilibrium. (Its ∆G° value at 25 °C is -2.1 kcal/mol.)
1448
views
Ch. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics
Bruice8th EditionOrganic ChemistryISBN: 9780135213711
Non è quello che usi tu?Cambia libro di testoScegli un libro di testo diverso
TOC.tableOfContents
- Ch. 1 - Remembering General Chemistry: Electronic Structure and Bonding31
- 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
Tutti i libri di testo
Bruice 8th EditionCh. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and KineticsProblema 22
Bruice 8th EditionCh. 5 - Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and KineticsProblema 22Capitolo 5, Problema 22
a. For a reaction with ∆H° = -12 kcal/mol and ∆S° = 0.01 kcal mol-1 K-1, calculate the ∆G° and the equilibrium constant at:
1. 30 °C and 2. 150 °C.
b. How does ∆G° change as T increases?
c. How does Keq change as T increases?
Guida verificata passo dopo passo1
Step 1: Recall the Gibbs free energy equation: ΔG° = ΔH° - TΔS°. Here, ΔH° is the enthalpy change, ΔS° is the entropy change, and T is the temperature in Kelvin. Convert the given temperatures (30 °C and 150 °C) to Kelvin using the formula T(K) = T(°C) + 273.
Step 2: For part (a), calculate ΔG° at each temperature using the Gibbs free energy equation. Substitute the values of ΔH° (-12 kcal/mol), ΔS° (0.01 kcal/mol·K), and the respective temperatures in Kelvin into the equation. Perform the subtraction to find ΔG° for each temperature.
Step 3: To calculate the equilibrium constant (Keq), use the relationship between ΔG° and Keq: ΔG° = -RT ln(Keq), where R is the gas constant (0.001987 kcal/mol·K). Rearrange the equation to solve for Keq: Keq = e^(-ΔG°/RT). Substitute the values of ΔG°, R, and T for each temperature to find Keq.
Step 4: For part (b), analyze how ΔG° changes as T increases. Since ΔG° = ΔH° - TΔS°, observe that the term TΔS° becomes larger as T increases. If ΔS° is positive, the magnitude of ΔG° decreases (becomes less negative or more positive) as T increases.
Step 5: For part (c), analyze how Keq changes as T increases. Since Keq = e^(-ΔG°/RT), if ΔG° becomes less negative or more positive as T increases, the exponent (-ΔG°/RT) becomes smaller, leading to a decrease in Keq. Conversely, if ΔG° becomes more negative, Keq increases.
Risposta video verificata per un problema simile:
Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.
Durata del video:
8mConcetti chiave
Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.
Gibbs Free Energy (∆G°)
Gibbs Free Energy (∆G°) is a thermodynamic potential that measures the maximum reversible work obtainable from a thermodynamic system at constant temperature and pressure. It is calculated using the equation ∆G° = ∆H° - T∆S°, where ∆H° is the change in enthalpy, T is the temperature in Kelvin, and ∆S° is the change in entropy. A negative ∆G° indicates a spontaneous reaction, while a positive value suggests non-spontaneity.
Video consigliato:
05:02
Breaking down the different terms of the Gibbs Free Energy equation.
Equilibrium Constant (Keq)
The equilibrium constant (Keq) quantifies the ratio of the concentrations of products to reactants at equilibrium for a reversible reaction. It is related to Gibbs Free Energy by the equation ∆G° = -RT ln(Keq), where R is the universal gas constant and T is the temperature in Kelvin. Changes in temperature can affect Keq, as they influence the position of equilibrium and the favorability of the reaction.
Video consigliato:
02:19The relationship between equilibrium constant and pKa.
Temperature Dependence of ∆G° and Keq
The temperature dependence of Gibbs Free Energy (∆G°) and the equilibrium constant (Keq) is significant in thermodynamics. As temperature increases, the term T∆S° becomes more influential in the Gibbs Free Energy equation, potentially leading to a decrease in ∆G° if ∆S° is positive. Consequently, an increase in temperature can shift the equilibrium constant (Keq), favoring the formation of products or reactants depending on the sign of ∆H° and ∆S°.
Video consigliato:
Percorso guidato
1:44Polymers Structure and Properties Concept 3
Pratica correlata
Domanda del libro di testo
What alkene would you start with if you wanted to synthesize
b. ethylcyclopentane?
1165
views
Domanda del libro di testo
What alkene would you start with if you wanted to synthesize
a. pentane?
1163
views
Domanda del libro di testo
Why is the percentage of molecules with the substituent in an equatorial position greater for isopropylcyclohexane than for fluorocyclohexane?
1103
views
Domanda del libro di testo
a. For which reaction in each set will ∆S° be more significant?
b. For which reaction will ∆S° be positive?
1. A ⇌ B or A + B ⇌ C
2. A ⇌ B + C or A + B ⇌ C + D
1426
views
Domanda del libro di testo
How many different alkenes can be hydrogenated to form
a. butane?
b. 3-methylpentane?
1310
views