Textbook Question
Calculate ∆H° for the following equilibrium processes.
(d)
1297
views
Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch. 2 - General Chemistry Translated: Finding the Electrons114
- Ch. 3 - Alkanes and Cycloalkanes: Properties and Conformational Analysis109
- Ch. 4 - Acids and Bases: Electron Flow144
- Ch. 5 - Chemical Reaction Analysis: Thermodynamics and Kinetics118
- Ch. 6 - Stereoisomerism: Arrangement of Atoms in Space112
- Ch. 7 - Principles of Green (Organic) Chemistry3
- Ch. 8 - Alkenes I: Properties and Electrophilic Additions158
- Ch. 9 - Alkenes II: Oxidation and Reduction150
- Ch. 10 - Alkynes: Electrophilic Addition and Redox Reactions101
- Ch. 11 - Properties and Synthesis of Alkyl Halides: Radical Reactions108
- Ch. 12 - Substitution and Elimination: Reactions of Haloalkanes172
- Ch. 13 - Alcohols, Ethers and Related Compounds: Substitution and Elimination239
- Ch. 14 - Structural Identification I: Infrared Spectroscopy and Mass Spectrometry54
- Ch. 15 - Structural Identification II: Nuclear Magnetic Resonance Spectroscopy93
- Ch. 16 - Metals in Organic Chemistry48
- Ch. 17 - Carbonyl Addition Reactions: Aldehydes and Ketones45
- Ch. 18 - Nucleophilic Acyl Substitution I: Carboxylic Acids18
- Ch. 19 - Nucleophilic Acyl Substitution II: Carboxylic Acid Derivatives39
- Ch. 20 - Enolates: Carbonyl Addition and Substitution13
- Ch. 21 - Conjugated Systems I: Stability and Addition Reactions56
- Ch. 22 - Conjugated Systems II: Pericyclic Reactions54
- Ch. 23 - Benzene I: Aromatic Stability and Substitution Reactions64
- Ch. 24 - Benzene II: Reactions Influenced by the Aromatic Ring62
- Ch. 25 - Amines: Structure, Reactions, and Synthesis27
- Ch. 26 - Amino Acids, Proteins, and Peptide Synthesis9
- Ch. 27 - Carbohydrates, Nucleic Acids, and Lipids54
Mullins1st EditionOrganic Chemistry: A Learner Centered ApproachISBN: 9780137566471Not the one you use?Change textbook
All textbooks
Mullins 1st EditionCh. 5 - Chemical Reaction Analysis: Thermodynamics and KineticsProblem 16c
Mullins 1st EditionCh. 5 - Chemical Reaction Analysis: Thermodynamics and KineticsProblem 16cChapter 4, Problem 16c
Which conformation in each of the following pairs has the least strain energy?
(c) 
Verified step by step guidance1
Identify the type of strain energy present in the molecule. Strain energy can arise from torsional strain (eclipsing interactions), steric strain (atoms or groups being too close to each other), or angle strain (bond angles deviating from their ideal values).
Analyze the conformations in the given pair. For example, if the molecule is a cyclohexane derivative, determine whether the conformation is in a chair, boat, or twist-boat form, as these have different strain energies.
If the molecule is a cyclohexane derivative, evaluate the placement of substituents in axial and equatorial positions. Substituents in the equatorial position generally reduce steric strain compared to axial positions.
Compare the torsional strain in the conformations. For example, staggered conformations (e.g., anti or gauche) typically have lower torsional strain than eclipsed conformations.
Select the conformation with the least strain energy by considering all the factors (torsional, steric, and angle strain) and determining which conformation minimizes these interactions.
Verified video answer for a similar problem:
This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1mWas this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Conformational Analysis
Conformational analysis involves studying the different spatial arrangements of atoms in a molecule that can be interconverted by rotation around single bonds. This analysis helps in understanding the stability of various conformations, as certain arrangements can lead to steric hindrance or torsional strain, affecting the overall energy of the molecule.
Recommended video:
Guided course
03:29
Understanding what a conformer is.
Strain Energy
Strain energy refers to the energy stored in a molecule due to the distortion of its normal bond angles and lengths. In organic molecules, factors such as steric strain (from repulsion between atoms) and torsional strain (from eclipsing interactions) contribute to the overall strain energy, influencing the stability and reactivity of different conformations.
Recommended video:
Guided course
02:46What is angle strain?
Staggered vs. Eclipsed Conformations
In conformational analysis, staggered and eclipsed conformations are two key arrangements of atoms around a single bond. Staggered conformations, where atoms are positioned at maximum distance from each other, generally have lower energy and less strain compared to eclipsed conformations, where atoms are aligned and experience increased steric and torsional strain.
Recommended video:
Guided course
03:29Understanding what a conformer is.
Related Practice
Textbook Question
For each of the following processes, indicate whether you expect ∆S° to be greater than, less than, or equal to 0. Explain your answer.
(b) 2 C6H14(l) + 19 O2(g) → 12 CO2(g) + 14 H2O(g)
678
views
Textbook Question
For each of the following processes, indicate whether you expect ∆S° to be greater than, less than, or equal to 0. Explain your answer.
(a) Boiling water
687
views
Textbook Question
The combustion of alkanes is exothermic (∆H° < 0) . Would you expect the combustion of butane or cyclobutane to be more exothermic?
1057
views
Textbook Question
Which conformation in each of the following pairs has the least strain energy?
(a)
1051
views
Textbook Question
Which conformation in each of the following pairs has the least strain energy?
(b)
893
views